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Background Limited data from small series have suggested that brain metastases from biliary tract cancers (BrM-BTC) affect ≤2% of patients with BTC. We sought to review our experience with patients with BrM-BTC and to identify associations of tumor-related molecular alterations with outcomes. Materials and Methods A retrospective review of patients with BTC seen at a tertiary referral center from 2005 to 2021 was performed; patients with BrM-BTC were identified, and clinical and molecular data were collected. Results Twenty-one of 823 patients with BTC (2.6%) developed BrM. For patients with BrM-BTC, median follow-up time was 27.9 months after primary BTC diagnosis and 3.1 months after BrM diagnosis. Median time from primary diagnosis to diagnosis of BrM was 14.4 [range, 1.1-66.0] months. Median overall survival (OS) from primary diagnosis was 31.5 [2.9-99.8] months and median OS from BrM diagnosis was 4.2 [0.2-33.8] months. Patients who underwent BrM-directed therapy trended toward longer OS following BrM diagnosis than patients receiving supportive care only (median 6.5 vs 0.8 months, P = .060). The BrM-BTC cohort was enriched for BRAF (30%), PIK3CA (25%), and GNAS (20%) mutations. patients with BrM-BTC with BRAF mutations trended toward longer OS following BrM diagnosis (median 13.1 vs 4.2 months, P = .131). Conclusion This is the largest series of patients with BrM-BTC to date and provides molecular characterization of this rare subgroup of patients with BTC. Patients with BrM-BTC may be more likely to have BRAF mutations. With advances in targeted therapy for patients with BTC with actionable mutations, continued examination of shifting patterns of failure, with emphasis on BrM, is warranted.

Definitive radiation therapy with concurrent chemotherapy is curative for nonmetastatic squamous cell carcinoma of the anus (SCCA). However, the true effect of chemoradiation on long-term functional outcomes is poorly understood owing to limited follow-up and patient-reported outcomes (PROs).We conducted a cross-sectional survey of 248 patients with SCCA treated with definitive intensity modulated radiation and concurrent chemotherapy from 2010 to 2018 who were alive and without recurrence. PRO measures were collected, including Functional Assessment of Cancer Therapy-General (FACT-G7), Fecal Incontinence Quality of Life (FIQoL), Low Anterior Resection Syndrome (LARS), and International Consultation on Incontinence Questionnaires (ICIQ). Models were used to determine the association between demographic, tumor, treatment, and dosimetric data with PROs.One hundred twelve (45%) patients completed PROs. Median [interquartile range (IQR)] time from radiation completion to survey was 51 [37-85] months. The median scores [IQR] for FACT-G7, FIQoL, and LARS were 21 [15-24], 14 [11-16], and 32 [25-37], respectively. For men, median subscores [IQR] for ICIQ voiding and incontinence subscores were 5 [2-6] and 1 [1-3], respectively. For women, median subscores [IQR] for ICIQ voiding, incontinence, and filling were 1 [1-3], 5 [3-8], and 4 [2-5], respectively. Higher (better) FIQoL scores were associated with higher (better) FACT-G7 scores (β = 0.83; 95% confidence interval, 0.58-1.09; P.001), and higher (worse) LARS scores were associated with lower (worse) FACT-G7 scores (β = -0.22; 95% confidence interval, -0.31 to -0.13; P.001). A separate multivariable analysis revealed higher bowel bag D1% was associated with lower (worse) FIQoL (P = .001) and higher (worse) LARS (P = .003) scores. Higher bladder V40 Gy was associated with increased (worse) ICIQ voiding subscore (P = .001).Patients treated with modern chemoradiation for SCCA experience significant long-term bowel toxic effects with considerable effect on quality of life. Minimizing bowel hotspots and bladder V40 Gy may improve bowel and urinary function. Other interventions to reduce long-term toxic effects and improve quality of life are needed.

The benefit of radiation therapy for pancreatic ductal adenocarcinoma (PDAC) remains unclear. We hypothesized that a new mechanistic mathematical model of chemotherapy and radiation response could predict clinical outcomes a priori, using a previously described baseline measurement of perfusion from computed tomography scans, normalized area under the enhancement curve (nAUC).We simplified an existing mass transport model that predicted cancer cell death by replacing previously unknown variables with averaged direct measurements from randomly selected pathologic sections of untreated PDAC. This allowed using nAUC as the sole model input to approximate tumor perfusion. We then compared the predicted cancer cell death to the actual cell death measured from corresponding resected tumors treated with neoadjuvant chemoradiation in a calibration cohort (n = 80) and prospective cohort (n = 25). After calibration, we applied the model to 2 separate cohorts for pathologic and clinical associations: targeted therapy cohort (n = 101), cetuximab/bevacizumab + radiosensitizing chemotherapy, and standard chemoradiation cohort (n = 81), radiosensitizing chemotherapy to 50.4 Gy in 28 fractions.We established the relationship between pretreatment computed v nAUC to pathologically verified blood volume fraction of the tumor (r = 0.65; P = .009) and fractional tumor cell death (r = 0.97-0.99; P.0001) in the calibration and prospective cohorts. On multivariate analyses, accounting for traditional covariates, nAUC independently associated with overall survival in all cohorts (mean hazard ratios, 0.14-0.31). Receiver operator characteristic analyses revealed discrimination of good and bad prognostic groups in the cohorts with area under the curve values of 0.64 to 0.71.This work presents a new mathematical modeling approach to predict clinical response from chemotherapy and radiation for PDAC. Our findings indicate that oxygen/drug diffusion strongly influences clinical responses and that nAUC is a potential tool to select patients with PDAC for radiation therapy.

Human papillomavirus (HPV) infection causes 600,000 new cancers worldwide each year. HPV-related cancers express the oncogenic proteins E6 and E7, which could serve as tumor-specific antigens. It is not known whether immunity to E6 and E7 evolves during chemoradiotherapy or affects survival. Using T cells from 2 HPV16+ patients, we conducted functional T-cell assays to identify candidate HPV-specific T cells and common T-cell receptor motifs, which we then analyzed across 86 patients with HPV-related cancers. The HPV-specific clones and E7-related T-cell receptor motifs expanded in the tumor microenvironment over the course of treatment, whereas non–HPV-specific T cells did not. In HPV16+ patients, improved recurrence-free survival was associated with HPV-responsive T-cell expansion during chemoradiotherapy.

Background Although intensity-modulated radiation therapy (IMRT) is considered the standard of care for the treatment of squamous cell carcinoma of the anus (SCCA), few large series have reported oncologic outcomes and toxicities. In this retrospective report, we aim to describe outcomes and toxicities after IMRT-based chemoradiation (CRT) for the treatment of SCCA, evaluate the impact of dose escalation (>54 Gy), and compare concurrent fluoropyrimidine in combination with either mitomycin or with cisplatin as chemosensitizers. Methods Patients treated at The University of Texas MD Anderson Cancer Center between January 1, 2003 and December 31, 2018 with IMRT-based CRT were included. Median time to locoregional recurrence, time to colostomy, and overall survival were estimated using the Kaplan–Meier method. Results A total of 428 patients were included; median follow-up was 4.4 years. Three hundred and thirty-four patients (78.0%) were treated with concurrent cisplatin and fluoropyrimidine, and 160 (37.4%) with >54 Gy. Two- and 5-year freedom from locoregional failure, freedom from colostomy failure, and overall survival were 86.5% and 81.2%, respectively, 90.0% and 88.3%, respectively, and 93.6% and 85.8%, respectively. Neither dose escalation nor mitomycin-based concurrent chemotherapy resulted in improved outcomes. Mitomycin-based concurrent chemotherapy was associated with in approximately 2.5 times increased grade 3 or greater acute toxicity. Radiation dose >54 Gy was associated with approximately 2.6 times increased Grade 3 or greater chronic toxicity. Conclusions Our results suggest IMRT-based CRT with concurrent fluoropyrimidine and cisplatin is a safe and feasible option for patient with SCCA and may cause less acute toxicity. The role for radiation dose escalation is unclear and requires further study.

PURPOSE/OBJECTIVES: To estimate the effects of interfractional anatomic changes on dose to organs-at-risk (OARs) and tumors, as measured with cone-beam computed tomography (CBCT) image guidance for pancreatic stereotactic body radiotherapy (SBRT). MATERIALS/METHODS: We evaluated 11 patients with pancreatic cancer, whom were treated with SBRT (33–40 Gy in 5 fractions) using daily CT-on-rails (CTOR) image guidance immediately before treatment with breath-hold motion management. CBCT alignment was simulated in the treatment planning software by aligning the original planning CT to each fractional CTOR image set via fiducial markers. CTOR datasets were used to calculate fractional doses after alignment by applying the rigid shift of the planning CT and CTOR image sets to the planning treatment isocenter and recalculating the fractional dose. Accumulated dose to the gross tumor volume (GTV), tumor vessel interface (TVI), duodenum, small bowel, and stomach were calculated by summing the 5 fractional absolute dose-volume histograms (DVHs) into a single DVH for comparison with the original planned dose. RESULTS: Four patients had a GTV D100% of at least 1.5 Gy less than the fractional planned value in several fractions; 4 patients had fractional underestimation of duodenum dose by 1.0 Gy per fraction. The D1.0 cm(3)

PurposeDiscrepancies between planned and delivered dose to GI structures during radiation therapy (RT) of liver cancer may hamper the prediction of treatment outcomes. The purpose of this study is to develop a streamlined workflow for dose accumulation in a treatment planning system (TPS) during liver image-guided RT and to assess its accuracy when using different deformable image registration (DIR) algorithms.Materials and MethodsFifty-six patients with primary and metastatic liver cancer treated with external beam radiotherapy guided by daily CT-on-rails (CTOR) were retrospectively analyzed. The liver, stomach and duodenum contours were auto-segmented on all planning CTs and daily CTORs using deep-learning methods. Dose accumulation was performed for each patient using scripting functionalities of the TPS and considering three available DIR algorithms based on: (i) image intensities only; (ii) intensities + contours; (iii) a biomechanical model (contours only). Planned and accumulated doses were converted to equivalent dose in 2Gy (EQD2) and normal tissue complication probabilities (NTCP) were calculated for the stomach and duodenum. Dosimetric indexes for the normal liver, GTV, stomach and duodenum and the NTCP values were exported from the TPS for analysis of the discrepancies between planned and the different accumulated doses.ResultsDeep learning segmentation of the stomach and duodenum enabled considerable acceleration of the dose accumulation process for the 56 patients. Differences between accumulated and planned doses were analyzed considering the 3 DIR methods. For the normal liver, stomach and duodenum, the distribution of the 56 differences in maximum doses (D2%) presented a significantly higher variance when a contour-driven DIR method was used instead of the intensity only-based method. Comparing the two contour-driven DIR methods, differences in accumulated minimum doses (D98%) in the GTV were >2Gy for 15 (27%) of the patients. Considering accumulated dose instead of planned dose in standard NTCP models of the duodenum demonstrated a high sensitivity of the duodenum toxicity risk to these dose discrepancies, whereas smaller variations were observed for the stomach.ConclusionThis study demonstrated a successful implementation of an automatic workflow for dose accumulation during liver cancer RT in a commercial TPS. The use of contour-driven DIR methods led to larger discrepancies between planned and accumulated doses in comparison to using an intensity only based DIR method, suggesting a better capability of these approaches in estimating complex deformations of the GI organs.

Patients with gastrointestinal (GI) cancer frequently experience unplanned hospitalizations, but predictive tools to identify high-risk patients are lacking. We developed a machine learning model to identify high-risk patients.In the study, 1341 consecutive patients undergoing GI (abdominal or pelvic) radiation treatment (RT) from March 2016 to July 2018 (derivation) and July 2018 to January 2019 (validation) were assessed for unplanned hospitalizations within 30 days of finishing RT. In the derivation cohort of 663 abdominal and 427 pelvic RT patients, a machine learning approach derived random forest, gradient boosted decision tree, and logistic regression models to predict 30-day unplanned hospitalizations. Model performance was assessed using area under the receiver operating characteristic curve (AUC) and prospectively validated in 161 abdominal and 90 pelvic RT patients using Mann-Whitney rank-sum test. Highest quintile of risk for hospitalization was defined as "high-risk" and the remainder "low-risk." Hospitalizations for high- versus low-risk patients were compared using Pearson's χOverall, 13% and 11% of patients receiving abdominal and pelvic RT experienced 30-day unplanned hospitalization. In the derivation phase, gradient boosted decision tree cross-validation yielded AUC = 0.823 (abdominal patients) and random forest yielded AUC = 0.776 (pelvic patients). In the validation phase, these models yielded AUC = 0.749 and 0.764, respectively (P.001 and P = .002). Validation models discriminated high- versus low-risk patients: in abdominal RT patients, frequency of hospitalization was 39% versus 9% in high- versus low-risk groups (P.001) and 6-month survival was 67% versus 92% (P = .001). In pelvic RT patients, frequency of hospitalization was 33% versus 8% (P = .002) and survival was 86% versus 92% (P = .15) in high- versus low-risk patients.In patients with GI cancer undergoing RT as part of multimodality treatment, machine learning models for 30-day unplanned hospitalization discriminated high- versus low-risk patients. Future applications will test utility of models to prompt interventions to decrease hospitalizations and adverse outcomes.

Introduction For maximum utility of molecular characterization by next-generation sequencing (NGS) and better understanding of tumor microenvironment with immune correlates analysis, biopsy specimens must yield adequate tumor tissue, and sequential biopsy specimens should sample a consistent site. We developed a web-based lesion selection tool (LST) that enables management and tracking of the biopsy specimen collections. Methods Of 145 patients, the LST was used for 88 patients; the other 57 served as controls. We evaluated consistency of the lesion biopsied in longitudinal collections, number of cores obtained, and cores with adequate tumor cellularity for NGS. The Fisher exact test and Wilcoxon rank sum test were used to identify differences between the groups. Results The analysis included 30 of 88 (34%) patients in the LST group and 52 of 57 (91%) in the control group. The LST workflow ensured 100% consistency in the lesions biopsied compared with 75% in the control group in longitudinal collections and increased the proportion of patients in whom at least five cores were collected per biopsy. Conclusions The novel LST platform facilitates coordination, performance, and management of longitudinal biopsy specimens. Use of the LST enables sampling of the designated lesion consistently, which is likely to accurately inform us the effect of the treatment on tumor microenvironment and evolution of resistant pathways. Such studies are important translational component of any clinical trials and research as they guide the development of next line of therapy, which has significant effect on clinical utility. However, validation of this approach in a larger study is warranted.

Pancreatic ductal adenocarcinoma (PDAC) is almost uniformly fatal and characterized by early metastasis. Oncogenic KRAS mutations prevail in 95% of PDAC tumors and co-occur with genetic alterations in the TP53 tumor suppressor in nearly 70% of patients. Most TP53 alterations are missense mutations that exhibit gain-of-function phenotypes that include increased invasiveness and metastasis, yet the extent of direct cooperation between KRAS effectors and mutant p53 remains largely undefined. We show that oncogenic KRAS effectors activate CREB1 to allow physical interactions with mutant p53 that hyperactivate multiple prometastatic transcriptional networks. Specifically, mutant p53 and CREB1 upregulate the prometastatic, pioneer transcription factor FOXA1, activating its transcriptional network while promoting WNT/β-catenin signaling, together driving PDAC metastasis. Pharmacologic CREB1 inhibition dramatically reduced FOXA1 and β-catenin expression and dampened PDAC metastasis, identifying a new therapeutic strategy to disrupt cooperation between oncogenic KRAS and mutant p53 to mitigate metastasis. Significance: Oncogenic KRAS and mutant p53 are the most commonly mutated oncogene and tumor suppressor gene in human cancers, yet direct interactions between these genetic drivers remain undefined. We identified a cooperative node between oncogenic KRAS effectors and mutant p53 that can be therapeutically targeted to undermine cooperation and mitigate metastasis. This article is highlighted in the In This Issue feature, p. 1861

Neoadjuvant FOLFIRINOX and gemcitabine/nab-paclitaxel (GemNP) therapies are increasingly used to treat patients with pancreatic ductal adenocarcinoma (PDAC). However, limited data are available on their clinicopathologic prognosticators. We examined the clinicopathologic factors and survival of 213 PDAC patients who received FOLFIRINOX with 71 patients who received GemNP. The FOLFIRINOX group was younger (p < 0.01) and had a higher rate of radiation (p = 0.049), higher rate of borderline resectable and locally advanced disease (p < 0.001), higher rate of Group 1 response (p = 0.045) and lower ypN stage (p = 0.03) than the GemNP group. Within FOLFIRINOX group, radiation was associated with decreased lymph node metastasis (p = 0.01) and lower ypN stage (p = 0.01). The tumor response group, ypT, ypN, LVI and PNI, correlated significantly with both DFS and OS (p < 0.05). Patients with the ypT0/T1a/T1b tumor had better DFS (p = 0.04) and OS (p = 0.03) than those with ypT1c tumor. In multivariate analysis, the tumor response group and ypN were independently prognostic factors for DFS and OS (p < 0.05). Our study demonstrated that the FOLFIRINOX group was younger and had a better pathologic response than the GemNP group and that the tumor response group, ypN, ypT, LVI and PNI, are significant prognostic factors for survival in these patients. Our results also suggest that the tumor size of 1.0 cm is a better cut off for ypT2. Our study highlights the importance of systemic pathologic examination and the reporting of post-treatment pancreatectomies.

Single-institution studies have shown the oncologic benefit of ablative liver radiotherapy (A-RT) for patients with unresectable intrahepatic cholangiocarcinoma (ICC). However, adoption of A-RT across the United States and its associated outcomes are unknown.We queried the National Cancer Data Base for nonsurgically managed patients with ICC diagnosed between 2004 and 2018. Patients were labeled A-RT for receipt of biologically effective doses (BEDOf 27,571 patients, the most common treatments were chemotherapy without liver RT (45%), no chemotherapy or liver RT (42%), and liver RT ± chemotherapy (13%). Use of liver RT remained constant over time. Of 1112 patients receiving liver RT with known doses, RT was 73% Conv-RT (median BEDAlthough A-RT has been increasingly used, use of liver RT as a whole in the United States remained constant despite growing evidence supporting its use, suggesting continued unmet need. A-RT is associated with longer survival versus Conv-RT.Bile duct cancer is a rare, deadly disease that often presents at advanced stages. Single-institution retrospective studies have demonstrated that use of high-dose radiotherapy may be associated with longer survival, but larger studies have not been conducted. We used a large, national cancer registry of patients diagnosed between 2004 and 2018 to show that liver radiotherapy use remains low in the United States, despite growing evidence that patients who receive it live longer. Furthermore, we showed that patients who received high-dose radiotherapy lived longer than those who received lower doses. Greater awareness of the benefits of liver radiotherapy is needed to improve patient outcomes.

The critical roles of oxygen homeostasis in metabolism are indisputable and hypoxic responses are correlated with the pathogenesis of gastrointestinal, pulmonary, renal diseases and cancers. Evaluating tissue hypoxia to predict treatment outcome is challenging, however, due to the lack of rapid, accurate and non-invasive methods. Hypoxia enhances prolyl-4-hydroxylase α1 (P4HA1) expression, which can convert bradykinin (BK) to hydroxyprolyl-BK (Hyp-BK), leading us to hypothesize that circulating Hyp-BK/BK ratios may reflect tissue hypoxia and predict treatment outcomes. Direct quantification of Hyp-BK peptides in serum or plasma by conventional MALDI-TOF MS analysis is technically challenging. In our study, a nanopore-based fractionation and enrichment protocol was utilized to allow the simple workflow for circulating Hyp-BK/BK analysis. Hypoxia is linked to poor prognosis due to its role in promoting pancreatic cancer progression and metastasis. Here we show that P4HA1 expression was increased in pancreatic tumors versus adjacent tissue, associated with poor survival, and corresponded with tumor expression of the hypoxia inducible factor 1α (HIF-1α) and carbonic anhydrase 9 (CA9). Hypoxia-induced P4HA1 expression and BK conversion to Hyp-BK were found to be HIF-1α dependent, pre-treatment serum Hyp-BK/BK ratios corresponded with tissue HIF-1α and P4HA1 expression, and high Hyp-BK/BK levels corresponded with poor response to therapy. These results suggest that pre-treatment circulating Hyp-BK/BK ratios may have value as a non-invasive, surrogate indicator of tissue hypoxia and tumor responses to therapy.

Effective consolidative chemoradiation (CRT) regimens are lacking. In this phase 1 trial, we evaluated the safety and efficacy of nab-paclitaxel, capecitabine, and radiation therapy after induction chemotherapy in patients with locally advanced and borderline-resectable pancreatic cancer (LAPC and BRPC). Also, we evaluated a computed tomography (CT)-based biomarker of response.Eligible patients had pathologically confirmed pancreatic ductal adenocarcinoma, underwent computed tomography-imaging, received a diagnosis of LAPC or BRPC, and received induction chemotherapy. Standard 3 + 3 study design was used, with 3 escalating nab-paclitaxel dose levels (50, 75, and 100 mg/mTwenty-three patients started and finished on protocol (LAPC = 14, BRPC = 9). No grade 3 and 4 toxicities were reported in level 1 (n = 3) or level 2 (n = 3) initial groups. Two patients in the initial level 3 group developed dose limiting toxicity, establishing level 2 dose as the maximal tolerated dose. Level 2 group was expanded for additional 15 patients (for a total of 23 on trial), 5 of whom developed grade 3 toxicities. Seven patients underwent surgical resection. Median OS and PFS were 21.2 and 8.1 months, respectively. Type I IR was associated with better OS (P = .004) and PFS (P = .03) compared with type II IR.We established the maximum tolerated dose for nab-paclitaxel in a consolidative CRT regimen for pancreatic ductal adenocarcinoma. Preliminary efficacy results warrant phase 2 trial evaluation. IR may be used for personalized treatment.

The identification of transcriptomic and protein biomarkers prognosticating recurrence risk after chemoradiation of localized squamous cell carcinoma of the anus (SCCA) has been limited by a lack of available fresh tissue at initial presentation. We analyzed archival FFPE SCCA specimens from pretreatment biopsies prior to chemoradiation for protein and RNA biomarkers from patients with localized SCCA who recurred (N = 23) and who did not recur (N = 25). Tumor cells and the tumor microenvironment (TME) were analyzed separately to identify biomarkers with significantly different expression between the recurrent and non-recurrent groups. Recurrent patients had higher mean protein expression of FoxP3, MAPK-activation markers (BRAF, p38-MAPK) and PI3K/Akt activation (phospho-Akt) within the tumor regions. The TME was characterized by the higher protein expression of immune checkpoint biomarkers such as PD-1, OX40L and LAG3. For patients with recurrent SCCA, the higher mean protein expression of fibronectin was observed in the tumor and TME compartments. No significant differences in RNA expression were observed. The higher baseline expression of immune checkpoint biomarkers, together with markers of MAPK and PI3K/Akt signaling, are associated with recurrence following chemoradiation for patients with localized SCCA. These data provide a rationale towards the application of immune-based therapeutic strategies to improve curative-intent outcomes beyond conventional therapies for patients with SCCA.

Background: Optimal patient selection for radiotherapy in pancreatic ductal adenocarcinoma (PDAC) is unestablished. Molecular profiling may select patients at high risk for locoregional recurrence (LRR) who would benefit from radiation. Methods: We included resectable pancreatic cancer (R-PDAC) patients, divided into training and validation cohorts, treated among three institutions with surgery and adjuvant chemotherapy, and borderline resectable or locally advanced pancreatic cancer (BR/LA-PDAC) patients treated with chemotherapy with or without radiation at the primary study institution. We isolated RNA from R-PDAC surgical specimens. Using NanoString, we identified miRNAs differentially expressed between normal and malignant pancreatic tissue. ElasticNet regression identified two miRNAs most predictive of LRR in the training cohort, miR-181b/d and miR-575, which were used to generate a risk score (RS). We evaluated the association of the median-dichotomized RS with recurrence and overall survival (OS). Results: We identified 183 R-PDAC and 77 BR/LA-PDAC patients with median follow up of 37 months treated between 2001 and 2014. On multivariable analysis of the R-PDAC training cohort (n = 90), RS was associated with worse LRR (HR = 1.34, 95%CI 1.27–11.38, p = 0.017) and OS (HR = 2.89, 95%CI 1.10–4.76, p = 0.027). In the R-PDAC validation cohort, RS was associated with worse LRR (HR = 2.39, 95%CI 1.03–5.54, p = 0.042), but not OS (p = 0.087). For BR/LA-PDAC, RS was associated with worse LRR (HR = 2.71, 95%CI 1.14–6.48, p = 0.025), DR (HR = 1.93, 95%CI 1.10–3.38, p = 0.022), and OS (HR = 1.97, 95%CI 1.17–3.34, p = 0.011). Additionally, after stratifying by RS and receipt of radiation in BR/LA-PDAC patients, high RS patients who did not receive radiation had worse LRR (p = 0.018), DR (p = 0.006), and OS (p &lt, 0.001) compared to patients with either low RS or patients who received radiation, irrespective of RS. Conclusions: RS predicted worse LRR and OS in R-PDAC and worse LRR, DR, and OS in BR/LA-PDAC. This may select patients who would benefit from radiation and should be validated prospectively.

Purpose: Intraductal papillary mucinous neoplasms (IPMN) are bona fide precursors to pancreatic ductal adenocarcinoma (PDAC). While genomic alterations during multistep IPMN progression have been well cataloged, the accompanying changes within the tumor immune microenvironment (TIME) have not been comprehensively studied. Herein, we investigated TIME-related alterations during IPMN progression, using multiplex immunofluorescence (mIF) coupled with high-resolution image analyses. Experimental Design: Two sets of formalin-fixed, paraffin-embedded tissue samples from surgically resected IPMNs were analyzed. The training set of 30 samples consisted of 11 low-grade IPMN (LG-IPMN), 17 high-grade IPMN (HG-IPMN), and 2 IPMN with PDAC, while a validation set of 93 samples comprised of 55 LG-IPMN and 38 HG-IPMN. The training set was analyzed with two panels of immuno-oncology–related biomarkers, while the validation set was analyzed with a subset of markers found significantly altered in the training set. Results: Cell types indicative of enhanced immune surveillance, including cytotoxic and memory T cells, and antigen-experienced T cells and B cells, were all found at higher densities within isolated LG-IPMNs compared with HG-IPMNs. Notably, the TIME of LG-IPMNs that had progressed at the time of surgical resection (progressor LGD) resembled that of the synchronous HG-IPMNs, underscoring that attenuated immune surveillance occurs even in LG-IPMNs destined for progression. Conclusions: Our findings provide a basis for interception of cystic neoplasia to PDAC, through maintenance of sustained immune surveillance using vaccines and other prevention approaches.

PURPOSE Effective preoperative regimens and biomarkers for pancreatic ductal adenocarcinoma (PDAC) are lacking. We prospectively evaluated fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX)-based treatment and imaging-based biomarkers for borderline resectable PDAC. METHODS Eligible patients had treatment-naïve, histology-confirmed PDAC and one or more high-risk features: mesenteric vessel involvement, CA 19-9 level of 500 mg/dL or greater, and indeterminate metastatic lesions. Patients received modified FOLFIRINOX and chemoradiation before anticipated pancreatectomy. Tumors were classified on baseline computed tomography as high delta (well-defined interface with parenchyma) or low delta (ill-defined interface). We designated computed tomography interface response after therapy as type I (remained or became well defined) or type II (became ill defined). The study had 80% power to differentiate a 60% from 40% resection rate (α = .10). Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method, and subgroups were compared using log-rank tests. RESULTS Thirty-three patients initiated therapy; 45% underwent pancreatectomy. The median OS was 24 months (95% CI, 16.2 to 29.6 months). For patients who did and did not undergo pancreatectomy, the median OS was 42 months (95% CI, 17.7 months to not estimable) and 14 months (95% CI, 9.0 to 24.8 months), respectively. Patients with high-delta tumors had lower 3-year PFS (4% v 40%) and 3-year OS rates (20% v 60%) than those with low-delta tumors (both P < .05). Patients with type II interface responses had lower 3-year PFS (0% v 29%) and 3-year OS rates (16% v 47%) than those with type I responses (both P < .001). CONCLUSION Preoperative FOLFIRINOX followed by chemoradiation for high-risk borderline resectable PDAC was associated with a resection rate of 45% and median OS of approximately 2 years. Our imaging-based biomarker validation indicates that personalized treatment may be achieved using these biomarkers at baseline and post-treatment.

Purpose Ablative radiation therapy is increasingly being used for hepatocellular carcinoma (HCC) resulting in excellent local control rates; however, patients without evidence of disease progression often die from liver failure. The clinical benefit of proton- over photon-based radiation therapy is unclear. We therefore sought to compare clinical outcomes of proton versus photon ablative radiation therapy in patients with unresectable HCC. Methods and Materials This is a single-institution retrospective study of patients treated during 2008 to 2017 with nonmetastatic, unresectable HCC not previously treated with liver-directed radiation therapy and who did not receive further liver-directed radiation therapy within 12 months after completion of index treatment. The primary outcome, overall survival (OS), was assessed using Cox regression. Secondary endpoints included incidence of non–classic radiation-induced liver disease (defined as increase in baseline Child-Pugh score by ≥2 points at 3 months posttreatment), assessed using logistic regression, and locoregional recurrence, assessed using Fine-Gray regression for competing risks. All outcomes were measured from radiation start date. Results The median follow-up was 14 months. Of 133 patients with median age 68 years and 75% male, 49 (37%) were treated with proton radiation therapy. Proton radiation therapy was associated with improved OS (adjusted hazard ratio, 0.47; P = .008; 95% confidence interval [CI], 0.27-0.82). The median OS for proton and photon patients was 31 and 14 months, respectively, and the 24-month OS for proton and photon patients was 59.1% and 28.6%, respectively. Proton radiation therapy was also associated with a decreased risk of non–classic radiation–induced liver disease (odds ratio, 0.26; P = .03; 95% CI, 0.08-0.86). Development of nonclassic RILD at 3 months was associated with worse OS (adjusted hazard ratio, 3.83; P Conclusions Proton radiation therapy was associated with improved survival, which may be driven by decreased incidence of posttreatment liver decompensation. Our findings support prospective investigations comparing proton versus photon ablative radiation therapy for HCC.

Pancreatic ductal adenocarcinoma (PDAC) is a deadly cancer that progresses without any symptom, and oftentimes, it is detected at an advanced stage. The lack of prior symptoms and effective treatments have created a knowledge gap in the management of this lethal disease. This issue can be addressed by developing novel noninvasive imaging-based biomarkers in PDAC. We explored in vivo hyperpolarized (HP) 13C MRS of pyruvate to lactate conversion and ex vivo 1H NMR spectroscopy in a panel of well-annotated patient-derived PDAC xenograft (PDXs) model and investigated the correlation between aberrant glycolytic metabolism and aggressiveness of the tumor. Real-time metabolic imaging data demonstrate the immediate intracellular conversion of HP 13C pyruvate to lactate after intravenous injection interrogating upregulated lactate dehydrogenase (LDH) activity in aggressive PDXs. Total ex vivo lactate measurement by 1H NMR spectroscopy showed a direct correlation with in vivo dynamic pyruvate-to-lactate conversion and demonstrated the potential of dynamic metabolic flux as a biomarker of total lactate concentration and aggressiveness of the tumor. Furthermore, the metabolite concentrations were very distinct among all four tumor types analyzed in this study. Overexpression of LDH-A and hypoxia-inducible factor (HIF-1α) plays a significant role in the conversion kinetics of HP pyruvate-to-lactate in tumors. Collectively, these data identified aberrant metabolic characteristics of pancreatic cancer PDXs and could potentially delineate metabolic targets for therapeutic intervention. Metabolic imaging with HP pyruvate and NMR metabolomics may enable identification and classification of aggressive subtypes of patient-derived xenografts. Translation of this real-time metabolic technique to the clinic may have the potential to improve the management of patients at high risk of developing pancreatic diseases.

When pancreatic cancer cannot be removed surgically, patients frequently experience morbidity and death from progression of their primary tumor. Radiation therapy (RT) cannot yet substitute for an operation because radiation causes fatal bleeding and ulceration of the nearby stomach and intestines before achieving tumor control. There are no FDA-approved medications that prevent or reduce radiation-induced gastrointestinal injury. Here, we overcome this fundamental problem of anatomy and biology with the use of the oral EGLN inhibitor FG-4592, which selectively protects the intestinal tract from radiation toxicity without protecting tumors. A total of 70 KPC mice with autochthonous pancreatic tumors received oral FG-4592 or vehicle control ± ablative RT to a cumulative 75 Gy administered in 15 daily fractions to a limited tumor field. Although ablative RT reduced complications from local tumor progression, fatal gastrointestinal bleeding was observed in 56% of mice that received high-dose RT with vehicle control. However, radiation-induced bleeding was completely ameliorated in mice that received high-dose RT with FG-4592 (0% bleeding, P < 0.0001 compared with vehicle). Furthermore, FG-4592 reduced epithelial apoptosis by half (P = 0.002) and increased intestinal microvessel density by 80% compared with vehicle controls. EGLN inhibition did not stimulate cancer growth, as treatment with FG-4592 alone, or overexpression of HIF2 within KPC tumors independently improved survival. Thus, we provide a proof of concept for the selective protection of the intestinal tract by the EGLN inhibition to enable ablative doses of cytotoxic therapy in unresectable pancreatic cancer by reducing untoward morbidity and death from radiation-induced gastrointestinal bleeding. Significance: Selective protection of the intestinal tract by EGLN inhibition enables potentially definitive doses of radiation therapy. This might allow radiation to be a surgical surrogate for unresectable pancreatic cancer.

IntroductionPancreatic adenocarcinoma (PAC) has some of the worst treatment outcomes for any solid tumor. PAC creates substantial difficulty for effective treatment with traditional RT delivery strategies primarily secondary to its location and limited visualization using CT. Several of these challenges are uniquely addressed with MR-guided RT. We sought to summarize and place into context the currently available literature on MR-guided RT specifically for PAC.MethodsA literature search was conducted to identify manuscript publications since September 2014 that specifically used MR-guided RT for the treatment of PAC. Clinical outcomes of these series are summarized, discussed, and placed into the context of the existing pancreatic literature. Multiple international experts were involved to optimally contextualize these publications.ResultsOver 300 manuscripts were reviewed. A total of 6 clinical outcomes publications were identified that have treated patients with PAC using MR guidance. Successes, challenges, and future directions for this technology are evident in these publications. MR-guided RT holds theoretical promise for the treatment of patients with PAC. As with any new technology, immediate or dramatic clinical improvements associated with its use will take time and experience. There remain no prospective trials, currently publications are limited to small retrospective experiences. The current level of evidence for MR guidance in PAC is low and requires significant expansion. Future directions and ongoing studies that are currently open and accruing are identified and reviewed.ConclusionsThe potential promise of MR-guided RT for PAC is highlighted, the challenges associated with this novel therapeutic intervention are also reviewed. Outcomes are very early, and will require continued and long term follow up. MR-guided RT should not be viewed in the same fashion as a novel chemotherapeutic agent for which dosing, administration, and toxicity has been established in earlier phase studies. Instead, it should be viewed as a novel procedural intervention which must be robustly tested, refined and practiced before definitive conclusions on the potential benefits or detriments can be determined. The future of MR-guided RT for PAC is highly promising and the potential implications on PAC are substantial.

PURPOSE/OBJECTIVE(S) Few studies have long-term follow-up assessing patient-reported outcomes (PROs) after intensity-modulated radiation therapy (IMRT)-based chemoradiation (CRT) for squamous cell carcinoma of the anus (SCCA). There is poor agreement between physician-graded toxicity and PROs regarding quality of life (QOL) in patients with SCCA. Therefore, we surveyed SCCA survivors ≥ 2 years out from CRT with validated PRO instruments assessing bowel, bladder, and sexual function. MATERIALS/METHODS We identified 248 patients with SCCA treated with definitive IMRT-based CRT at a large tertiary cancer center from 2010-2018, who were alive and without recurrence. Patients were asked to complete five PRO instruments: Fecal Incontinence QOL Scale (FIQOL), Low Anterior Resection Syndrome Score (LARS), International Consultation on Incontinence Questionnaire (ICIQ), male and female lower urinary tract symptoms (MLUTS and FLUTS, respectively), International Index of Erectile Function (IIEF), and Female Sexual Function Index (FSFI). FIQOL, LARS, IIEF, and FSFI scores were dichotomized and logistic regression used to identify predictors of QOL scores. RESULTS One hundred eight (44%) patients completed the PROs. Respondents' median [interquartile range, (IQR)] age was 66 [59-72] years, 80% were female, and 95% were white. Median [IQR] gross tumor volume (GTV) was 45 [27-71] cc; dose to GTV was 50 Gray (Gy), 54 Gy and 58 Gy in 25%, 53%, and 22%, respectively. Median [IQR] time from CRT was 51 [37-84] months. Median [IQR] FIQOL score was 14.3/20 [11.2-16.1]; higher is better. Larger GTV size (OR 0.99; P = 0.03) was associated with lower FIQOL score. Sixty-one (56%) patients met major LARS criteria. There was a trend towards a higher incidence of major LARS with GTV dose ≥ 54 Gy (OR 2.39; P = 0.08). Men had median [IQR] ICIQ MLUTS voiding and incontinence scores of 5/20 [2-6] and 1/24 [1-3], respectively. Women had median [IQR] ICIQ FLUTS voiding and incontinence scores of 1/12 [1-3] and 5/20 [3-8], respectively; higher is worse. Fifty-nine (55%) patients reported being sexually active in the last month. Men had a median [IQR] IIEF score of 14/25 [6-19]; higher is better. Only age (OR 1.17; P = 0.04) was significantly associated with IIEF ≤ 11 (moderate or severe ED). Women had a median [IQR] FSFI score of 20.2/26 [13.6-24.9]; higher is better. Age < 65 was associated with sexual dysfunction, defined as FSFI < 26.55 (OR, 5.5; P = 0.04). Forty (37%) patients disagreed or strongly disagreed that they were prepared for long-term side effects. Seventy (65%) patients agreed or strongly agreed that educational materials would have been helpful. CONCLUSION SCCA survivors experience significant long-term bowel and sexual toxicities from modern CRT. Larger tumors and higher RT doses may be associated with worse function. Interventions to reduce toxicities and improve patient education are needed.

PURPOSE/OBJECTIVE(S) Current GI toxicity models are limited by the uncertainty in the estimated delivered dose used to develop the models. The purpose of this study is to assess the benefit of harnessing deep learning and biomechanical models to improve the understanding of the dose-toxicity relationship. MATERIALS/METHODS Retrospective dose accumulation was conducted on 75 patients with primary and metastatic liver cancer treated with external beam radiotherapy guided by daily CT-on-rails (CTOR), based on a novel deformable image registration (DIR) approach that applies biomechanical model-based and intensity-based DIR inside and outside the liver, respectively. The liver was auto-segmented on all images using a clinically validated 2D deep learning model. On a sub-cohort, the combination of stomach and duodenum region of interest (GI ROI) was auto-contoured using a 3D UNet model trained independently on 102 patients. These contours were compared to physician-drawn contours on CTOR, using Dice similarity coefficient (DSC), mean distance to agreement (DTA), Hausdorff distance (HD), and planned dose metrics. Intra-observer variability was evaluated. Doses were converted to equivalent dose in 2Gy fractions (EQD2) for analysis (α/β = 3.5). Differences between planned and delivered dose were calculated, as well as GI ROI daily dose variation. Toxicity probability was calculated based on previously developed accumulated dose normal tissue complication probability (NTCP) models for duodenum and stomach. RESULTS Average (SD) DSC, DTA, and HD between the deep learning model and physician-drawn GI ROI were 0.9 (0.1), 0.2 (0.1) cm, and 2.4 (2.2) cm; intra-observer values were 0.9 (0.0), 0.1 (0.0) cm, and 2.3 (0.8) cm, P > 0.1. Average differences in volume (SD), D50 (SD), and D1 (SD) between the AI model and physician-drawn contours were 25.0 (36.7) cc, 0.6 (1.1) Gy, and 0.5 (0.2) Gy; intra-observer values were 7.1 (4.5) cc, 0.2 (0.3) Gy and 0.3 (0.3) Gy, P > 0.1. Average planned and accumulated D1 (EQD2) to the GI ROI were 28.1 Gy and 26.6 Gy, respectively. These distributions were significantly different (P < 0.01), with differences ranging from 0.2 Gy to 2.9 Gy. Daily D1 to the GI ROI varied by up to 47% (average 25%). For 38% of patients, relative differences in NTCP based on planned and accumulated dose were greater than 50%. Compared to planned dose, 63% of the patients had lower NTCP with accumulated dose, and 13% had higher NTCP. CONCLUSION Variability between AI-based and physician-drawn stomach and duodenum segmentation was equivalent to intra-observer variability. Accumulated dose showed statistically significant differences from planned dose for the stomach and duodenum leading to meaningful differences in NTCP. The daily variability in the maximum dose varied by an average of +/- 25%, demonstrating the potential to optimize daily fractionation based on anatomical configuration of the day.

PURPOSE/OBJECTIVE(S) Radiotherapy (RT) is increasingly used in advanced hepatocellular carcinoma (HCC), providing excellent local control. Regional and distant failures are common though, and radiation-induced liver disease (RILD) and post-RT lymphopenia have been shown to correlate with survival. In this study, we develop machine learning (ML) models to predict these endpoints and validate them using an independent dataset. MATERIALS/METHODS We developed Cox regression and random survival forests to estimate survival, and both linear (logistic regression) and nonlinear discriminant ML models (support vector machines and gradient boosted trees) for four binary endpoints: 1-year survival, non-local failure within 1 year (NLF1y), RILD defined as 2+ increase in Child Pugh score and lymphopenia (count < 0.5 109/L). Metrics include c-index for survival analysis, area under the ROC curve (AUC) and accuracy in the 10/20% highest risk groups for discriminant analysis. The models training considered 21 clinical and dosimetric variables evaluated in a nested cross-validation approach for feature selection and hyperparameter tuning. After locking the models, we used an unseen independent dataset for external validation without any further calibration. A study analysis plan detailing methodology was published before access to the external validation set. RESULTS 207 HCC patients treated at a single institution between 2008 and 2019 were used for model training and 143 patients from a different institution for external validation. The survival models discriminated well between low- and high-risk groups (Harrell's c = 0.72), patients classified above median risk had a significantly higher risk of death (HR = 3.2 (95% CI [2.1-4.9]), P < 0.001) with 9.4 months observed median survival compared to 33.2 months for the low-risk group. Discriminatory power for top versus bottom survival quartile increased to HR = 6.1 [3.3-11], median survival 5.4 vs 42.5 months. Binary classification performance for all endpoints was consistent between training and validation with an external AUC of 0.79 for 1-year survival (internal 0.75), and 0.64-0.68 for the other endpoints (internal 0.53-0.71). The models predict NLF1y in high/very-high risk groups (87/100% accuracy) and lymphopenia in the very high-risk group (65-85% accuracy). Notably platelet count is selected by all generative classifiers of RILD, indicating interaction with known predictors. CONCLUSION Independent validation of the models demonstrates the ability to accurately stratify patients by survival and discriminant endpoints with comparable performance on external validation, which underscores good generalizability. High prediction accuracy for sub-groups at high risk of non-local failure and lymphopenia could enable treatment modification in specific cases, while no approach reliably predicted RILD.

Human papillomavirus (HPV) infection causes 600,000 new cancers worldwide each year. HPV-related cancers express the oncogenic proteins E6 and E7, which could serve as tumor-specific antigens. It is not known whether immunity to E6 and E7 evolves during chemoradiotherapy (CRT) or affects survival. We used functional T-cell assays to identify candidate HPV-specific T-cells and T- cell motifs common across 86 patients with HPV-related cancers. These HPV-specific clones and E7-related motifs expanded over the course of treatment, whereas non-HPV-specific T-cells did not. In HPV16+ patients, improved recurrence-free survival was associated with this HPV-responsive T-cell expansion during CRT.

Previously, we characterized qualitative imaging-based subtypes of pancreatic ductal adenocarcinoma (PDAC) on computed tomography (CT) scans. Conspicuous (high delta) PDAC tumors are more likely to have aggressive biology and poorer clinical outcomes compared to inconspicuous (low delta) tumors. Here, we developed a quantitative classification of this imaging-based subtype (quantitative delta, q-delta). Retrospectively, baseline pancreatic protocol CT scans of three cohorts (cohort#1 = 101, cohort#2 = 90 and cohort#3 = 16 [external validation]) of patients with PDAC were qualitatively classified into high and low delta. We used a voxel-based method to volumetrically quantify tumor enhancement while referencing normal-pancreatic-parenchyma and used machine learning-based analysis to build a predictive model. In addition, we quantified the stromal content using hematoxylin- and eosin-stained treatment-na&iuml, ve PDAC sections. Analyses revealed that PDAC quantitative enhancement values are predictive of the qualitative delta scoring and were used to build a classification model (q-delta). Compared to high q-delta, low q-delta tumors were associated with improved outcomes, and the q-delta class was an independent prognostic factor for survival. In addition, low q-delta tumors had higher stromal content and lower cellularity compared to high q-delta tumors. Our results suggest that q-delta classification provides a clinically and biologically relevant tool that may be integrated into ongoing and future clinical trials.

BackgroundPreviously, we characterized subtypes of pancreatic ductal adenocarcinoma (PDAC) on computed-tomography (CT) scans, whereby conspicuous (high delta) PDAC tumors are more likely to have aggressive biology and poorer clinical outcomes compared to inconspicuous (low delta) tumors. Here, we hypothesized that these imaging-based subtypes would exhibit different growth-rates and distinctive metabolic effects in the period prior to PDAC diagnosis.Materials and methodsRetrospectively, we evaluated 55 patients who developed PDAC as a second primary cancer and underwent serial pre-diagnostic (T0) and diagnostic (T1) CT-scans. We scored the PDAC tumors into high and low delta on T1 and, serially, obtained the biaxial measurements of the pancreatic lesions (T0-T1). We used the Gompertz-function to model the growth-kinetics and estimate the tumor growth-rate constant (α) which was used for tumor binary classification, followed by cross-validation of the classifier accuracy. We used maximum-likelihood estimation to estimate initiation-time from a single cell (10-6 mm3) to a 10 mm3 tumor mass. Finally, we serially quantified the subcutaneous-abdominal-fat (SAF), visceral-abdominal-fat (VAF), and muscles volumes (cm3) on CT-scans, and recorded the change in blood glucose (BG) levels. T-test, likelihood-ratio, Cox proportional-hazards, and Kaplan-Meier were used for statistical analysis and p-value ResultsCompared to high delta tumors, low delta tumors had significantly slower average growth-rate constants (0.024 month−1 vs. 0.088 month−1, p−1. Leave-one-out-cross-validation showed 80% accuracy in predicting the delta-class (AUC=0.84). High delta tumors exhibited accelerated SAF, VAF, and muscle wasting (p ConclusionImaging-based subtypes of PDAC exhibit distinct growth, metabolic, and clinical profiles during the pre-diagnostic period. Our results suggest that heterogeneous disease biology may be an important consideration in early detection strategies for PDAC.

Local recurrences can sometimes occur after prior radiotherapy for abdominal and pelvic cancers. The management of these patients can be quite complex. We present a case of recurrent pancreatic cancer after prior chemoradiation and discuss various management options, with a focus on different approaches to reirradiation.

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is a heterogeneous disease with variable presentations and natural histories of disease. We hypothesized that different morphologic characteristics of PDAC tumors on diagnostic computed tomography (CT) scans would reflect their underlying biology. Experimental Design: We developed a quantitative method to categorize the PDAC morphology on pretherapy CT scans from multiple datasets of patients with resectable and metastatic disease and correlated these patterns with clinical/pathologic measurements. We modeled macroscopic lesion growth computationally to test the effects of stroma on morphologic patterns, hypothesizing that the balance of proliferation and local migration rates of the cancer cells would determine tumor morphology. Results: In localized and metastatic PDAC, quantifying the change in enhancement on CT scans at the interface between tumor and parenchyma (delta) demonstrated that patients with conspicuous (high-delta) tumors had significantly less stroma, higher likelihood of multiple common pathway mutations, more mesenchymal features, higher likelihood of early distant metastasis, and shorter survival times compared with those with inconspicuous (low-delta) tumors. Pathologic measurements of stromal and mesenchymal features of the tumors supported the mathematical model's underlying theory for PDAC growth. Conclusions: At baseline diagnosis, a visually striking and quantifiable CT imaging feature reflects the molecular and pathological heterogeneity of PDAC, and may be used to stratify patients into distinct subtypes. Moreover, growth patterns of PDAC may be described using physical principles, enabling new insights into diagnosis and treatment of this deadly disease.

To develop and validate a radiomics signature that can predict the clinical outcomes for patients with stage I non-small cell lung cancer (NSCLC).We retrospectively analyzed contrast-enhanced computed tomography images of patients from a training cohort (n = 147) treated with surgery and an independent validation cohort (n = 295) treated with stereotactic ablative radiation therapy. Twelve radiomics features with established strategies for filtering and preprocessing were extracted. The random survival forests (RSF) method was used to build models from subsets of the 12 candidate features based on their survival relevance and generate a mortality risk index for each observation in the training set. An optimal model was selected, and its ability to predict clinical outcomes was evaluated in the validation set using predicted mortality risk indexes.The optimal RSF model, consisting of 2 predictive features, kurtosis and the gray level co-occurrence matrix feature homogeneity2, allowed for significant risk stratification (log-rank P.0001) and remained an independent predictor of overall survival after adjusting for age, tumor volume and histologic type, and Karnofsky performance status (hazard ratio [HR] 1.27; P2e-16) in the training set. The resultant mortality risk indexes were significantly associated with overall survival in the validation set (log-rank P = .0173; HR 1.02, P = .0438). They were also significant for distant metastasis (log-rank P.05; HR 1.04, P = .0407) and were borderline significant for regional recurrence on univariate analysis (log-rank P.05; HR 1.04, P = .0617).Our radiomics model accurately predicted several clinical outcomes and allowed pretreatment risk stratification in stage I NSCLC, allowing the choice of treatment to be tailored to each patient's individual risk profile.

Purpose Irradiation may have significant immunomodulatory effects that impact tumor response and could potentiate immunotherapeutic approaches. The purposes of this study were to prospectively investigate circulating lymphoid cell population fractions during hypofractionated proton therapy (HPT) in blood samples of liver cancer patients and to explore their association with survival. Methods and Materials We collected serial blood samples before treatment and at days 8 and 15 of HPT from 43 patients with liver cancer—22 with hepatocellular carcinoma (HCC) and 21 with intrahepatic cholangiocarcinoma (ICC)—enrolled in a phase 2 clinical trial. All patients received 15 fractions of proton therapy to a median dose of 58 Gy (relative biological effectiveness). We used flow cytometry to measure the changes in the fractions of total CD3+, CD4+, and CD8+ T cells; CD4+ CD25+ T cells; CD4+ CD127+ T cells; CD3+ CD8+ CD25+ activated cytotoxic T lymphocytes (CTLs); and CD3– CD56+ natural killer cells. Results With a median follow-up period of 42 months, median overall survival (OS) in the study cohort was 30.6 months for HCC and 14.5 months for ICC patients. Longer OS was significantly correlated with greater CD4+ CD25+ T-cell (P = .003) and CD4+ CD127+ T-cell (P = .01) fractions at baseline only in ICC patients. In HCC patients, the fraction of activated CTLs mid treatment (at day 8) was significantly associated with OS (P = .007). These findings suggest a differential relevance of immunomodulation by HPT in these liver cancers. Conclusions Antitumor immunity may depend on maintenance of a sufficiently high number of activated CTLs during HPT in HCC patients and CD4+ CD25+ T cells and CD4+ CD127+ T cells prior to treatment in ICC patients. These results could guide the design of future studies to determine the optimal treatment schedules when combining irradiation with specific immunotherapy approaches.

Purpose To evaluate the effect of escalated dose radiation therapy (EDR, defined as doses >50.4 Gy in 28 fractions [59.5 Gy BED]) on overall survival (OS), freedom from local progression (FFLP), and freedom from distant progression (FFDP) of patients with unresectable extrahepatic cholangiocarcinoma (EHCC). Methods A consecutive cohort of 80 patients who underwent radiotherapy for unresectable EHCC from 2001 to 2015 was identified. Demographic, tumor, treatment, toxicity, and laboratory variables were collected. The maximal RT doses ranged from 30 to 75 Gy (median 50.4 Gy, at 1.8‐4.5 Gy/fraction). Gross tumor volume (GTV) coverage by maximal dose in EDR group ranged from 38% to 100%. Kaplan–Meier method was used to estimate OS, FFLP, and FFDP. Univariate and multivariate Cox regression models were analyzed. Results After radiotherapy, median OS, FFLP, and FFDP were 18.7, 22.6, and 24.3 months, respectively. There was no significant difference in OS or FFLP between patients who received EDR to portions of the GTV and patients who did not. On multivariate analysis, bigger GTV, age, and ECOG performance status were independently associated with shorter OS. Local progression on chemotherapy prior to RT was independently associated with shorter FFLP. High baseline neutrophil/lymphocyte ratio (>5.3) was independently associated with shorter FFDP. Toxicity grades were similar in EDR and lower doses except lymphopenia which was higher in EDR (P = 0.053). Conclusions EDR to selective portions of the GTV may not benefit patients with unresectable EHCC despite having acceptable toxicity. New methods to improve local control and survival for unresectable EHCC are needed.

Purpose: Understanding the mechanism of radioresistance could help develop strategies to improve therapeutic response of patients with PDAC. The SMAD4 gene is frequently mutated in pancreatic cancer. In this study, we investigated the role of SMAD4 deficiency in pancreatic cancer cells' response to radiotherapy. Experimental Design: We downregulated SMAD4 expression with SMAD4 siRNA or SMAD4 shRNA and overexpressed SMAD4 in SMAD4 mutant pancreatic cancer cells followed by clonogenic survival assay to evaluate their effects on cell radioresistance. To study the mechanism of radioresistance, the effects of SMAD4 loss on reactive oxygen species (ROS) and autophagy were determined by flow cytometry and immunoblot analysis, respectively. Furthermore, we measured radioresistance by clonogenic survival assay after treatment with autophagy inhibitor (Chloroquine) and ROS inhibitor (N-acetyl-l-cysteine) in SMAD4-depleted pancreatic cancer cells. Finally, the effects of SMAD4 on radioresistance were also confirmed in an orthotopic tumor model derived from SMAD4-depleted Panc-1 cells. Results: SMAD4-depleted pancreatic cancer cells were more resistant to radiotherapy based on clonogenic survival assay. Overexpression of wild-type SMAD4 in SMAD4-mutant cells rescued their radiosensitivity. Radioresistance mediated by SMAD4 depletion was associated with persistently higher levels of ROS and radiation-induced autophagy. Finally, SMAD4 depletion induced in vivo radioresistance in Panc-1-derived orthotopic tumor model (P = 0.038). More interestingly, we observed that the protein level of SMAD4 is inversely correlated with autophagy in orthotopic tumor tissue samples. Conclusions: Our results demonstrate that defective SMAD4 is responsible for radioresistance in pancreatic cancer through induction of ROS and increased level of radiation-induced autophagy. Clin Cancer Res; 24(13); 3176–85. ©2018 AACR.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers. It has an excessive desmoplastic stroma that can limit the intratumoral delivery of chemotherapy drugs, and protect tumor cells against radiotherapy. Therefore, both stromal and tumor compartments need to be addressed in order to effectively treat PDAC. We hereby co-deliver a sonic hedgehog inhibitor, cyclopamine (CPA), and a cytotoxic chemotherapy drug paclitaxel (PTX) with a polymeric micelle formulation (M-CPA/PTX). CPA can deplete the stroma-producing cancer-associated fibroblasts (CAFs), while PTX can inhibit tumor proliferation. Here we show that in clinically relevant PDAC models, M-CPA effectively modulates stroma by increasing microvessel density, alleviating hypoxia, reducing matrix stiffness while maintaining the tumor-restraining function of extracellular matrix. M-CPA/PTX also significantly extends animal survival by suppressing tumor growth and lowering the percentages of poorly to moderately differentiated tumor phenotypes. Our study suggests that using multifunctional nanoparticles to simultaneously target stromal and tumor compartments is a promising strategy for PDAC therapy.

Background The assessment of pancreatic ductal adenocarcinoma (PDAC) response to therapy remains challenging. The objective of this study was to investigate whether changes in the tumor/parenchyma interface are associated with response. Methods Computed tomography (CT) scans before and after therapy were reviewed in 4 cohorts: cohort 1 (99 patients with stage I/II PDAC who received neoadjuvant chemoradiation and surgery); cohort 2 (86 patients with stage IV PDAC who received chemotherapy), cohort 3 (94 patients with stage I/II PDAC who received protocol-based neoadjuvant gemcitabine chemoradiation), and cohort 4 (47 patients with stage I/II PDAC who received neoadjuvant chemoradiation and were prospectively followed in a registry). The tumor/parenchyma interface was visually classified as either a type I response (the interface remained or became well defined) or a type II response (the interface became poorly defined) after therapy. Consensus (cohorts 1-3) and individual (cohort 4) visual scoring was performed. Changes in enhancement at the interface were quantified using a proprietary platform. Results In cohort 1, type I responders had a greater probability of achieving a complete or near-complete pathologic response (21% vs 0%; P = .01). For cohorts 1, 2, and 3, type I responders had significantly longer disease-free and overall survival, independent of traditional covariates of outcomes and of baseline and normalized cancer antigen 19-9 levels. In cohort 4, 2 senior radiologists achieved a κ value of 0.8, and the interface score was associated with overall survival. The quantitative method revealed high specificity and sensitivity in classifying patients as type I or type II responders (with an area under the receiver operating curve of 0.92 in cohort 1, 0.96 in cohort 2, and 0.89 in cohort 3). Conclusions Changes at the PDAC/parenchyma interface may serve as an early predictor of response to therapy. Cancer 2018;124:1701-9. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Rationale: Exosomes are small extracellular vesicles secreted by most cells that are found in blood and other bodily fluids, and which contain cytoplasmic material and membrane factors corresponding to their cell type of origin. Exosome membrane factors and contents have been reported to alter adjacent and distant cell behavior in multiple studies, but the impact of cancer-derived exosomes on chemoresistance is less clear. Methods: Exosomes isolated from three pancreatic cancer (PC) cell lines displaying variable gemcitabine (GEM) resistance (PANC-1, MIA PaCa-2, and BxPC-3) were tested for their capacity to transmit chemoresistance among these cell lines. Comparative proteomics was performed to identify key exosomal proteins that conferred chemoresistance. Cell survival was assessed in GEM responsive PC cell lines treated with recombinant Ephrin type-A receptor 2 (EphA2), a candidate chemoresistance transfer factor, or exosomes from a chemoresistant PC cell line treated with or without EphA2 shRNA. Results: Exosomes from chemoresistant PANC-1 cells increased the GEM resistance of MIA PaCa-2 and BxPC-3 cell cultures. Comparative proteomics determined that PANC-1 exosomes overexpressed Ephrin type-A receptor 2 (EphA2) versus exosomes of less chemoresistant PC cell lines MIA PaCa-2 and BxPC-3. EphA2-knockdown in PANC-1 cells inhibited their ability to transmit exosome-mediated chemoresistance to MIA PaCa-2 and BxPC-3, while treatment of MIA PaCa-2 and BxPC-3 cells with soluble EphA2 did not promote chemoresistance, indicating that membrane carried EphA2 was important for the EphA2 chemoresistance effect. Conclusion: Exosomal EphA2 expression could transmit chemoresistance and may potentially serve as a minimally-invasive predictive biomarker for PC treatment response. Further work should address whether additional exosomal factors regulate resistance to other cancer therapeutic agents for PC or other cancer types.

PURPOSE/OBJECTIVE(S) Intrahepatic cholangiocarcinoma (iCCA) remains a highly lethal disease. Biomarkers are needed to identify pts who may benefit from specific therapeutic strategies. Here, we hypothesized that imaging features derived from pre-therapy CT are associated with histopathological and clinical outcomes. MATERIALS/METHODS Retrospectively, we identified 60 pts with localized iCCA (24 M, 36 F, median age 65 [range 26-84]), who received upfront resection as a discovery cohort (D1) and 87 pts with locally advanced iCCA (49 M, 38 F, median age 64 [range 30-88]) who received chemo and radiation therapy as a validation cohort (D2). Using the pre-therapy CT, we contoured the tumors in the arterial phase and used a voxel-based method to quantify the tumors enhancing volume (normalized to liver parenchyma), and called this quantification: volumetric enhancement (VE). Using the training cohort only, we performed receiver operating characteristic (ROC) analysis to evaluate the classification ability of VE in differentiating long vs short (36 months) overall survival (OS), and to obtain an optimal cut-off for validation in D2. Corresponding slides from resection specimens of 38 pts from D1 were stained with H&E and digitally analyzed to quantify the tumor infiltration percentage. We used Pearson correlation coefficient, likelihood ratio, Kaplan-Meier and Cox-proportional hazard for statistical analyses. RESULTS As a continuous variable, higher VE values were associated with better OS in D1 (RR = 0.97, 95% CI [0.95-0.99], P = 0.0007) and D2 (RR = 0.96, 95% CI [0.95-0.98], P < 0.0001). On multivariate analyses, VE as a continuous variable was an independent prognostic factor for OS accounting for traditional covariates in D1 (RR = 0.97, 95% CI [0.95-0.99], P = 0.002) and D2 (RR = 0.96, 95% CI [0.94-0.98], P < 0.0001). Using D1, VE demonstrated high accuracy in classifying pts with short vs. long term survival (Area under the curve (AUC) = 0.77), with an optimal threshold of 32.2% to dichotomize the VE into low versus high. Kaplan-Meier analysis showed that pts with high VE tumors had better median OS (145 vs 34 months, P = 0.002 and 46 vs 22 months, P < 0.0001), and distant metastasis free survival DMFS (107 vs 11 months, P < 0.0001 and 29 vs 13 months, P < 0.0001) compared to those with low VE tumors in D1 and D2 respectively. Pts with low VE tumors were more likely to have a higher nodal positivity rate compared to those with high VE tumors in D1 (P = 0.002). Tumors with high VE values had higher histopathological tumor infiltration percentage compared to those with lower VE values (⍴ = 0.72, P < 0.0001). CONCLUSION A CT-based measure of volumetric enhancement was associated with clinical and biological differences in resectable and unresectable iCCA, which may help personalize use of chemotherapy, radiation, and surgery in this disease.

PURPOSE/OBJECTIVE(S) The role of RT remains controversial in treating BRPC and LAPC following Alliance A021501 and LAP07. These studies shifted our institutional practice to more selective use of RT, whereas in the past, we most often consolidated with RT after chemotherapy (chemo). We reviewed our experience using modern multi-agent chemo with or without RT. MATERIALS/METHODS We utilized a retrospective registry to analyze 454 pts (240 M, 214 F, median age 65 [28 - 89]) who were diagnosed with BRPC (n = 172) or LAPC (n = 282) between 2011 to 2019 and who underwent chemo alone (n = 167) or chemo then RT (n = 287). For those pts who received RT, the median dose and fractionation was 50 Gy (30 - 98 Gy) and 15 fractions (4 - 28). Median biological effective dose was 60 Gy (33 - 132 Gy). All pts received FOLFIRINOX (n = 274) or gemcitabine/nab-paclitaxel (GnP, n = 180). Associations between chemo regimen (FOLFIRINOX vs. GnP), resection (surgery vs. no surgery), CA19-9 response (normalized vs. not vs. not applicable [N/A]), and other demographic characteristics were tested using the likelihood-ratio. CA19-9 normalizers were defined by the minimum CA19-9 value between the start of chemo and 6 mos post-chemo start that was < 40 U/mL. Pts were classified as N/A if the pt either had an abnormal bilirubin level or a CA19-9 < 40 U/mL at baseline, or were missing CA19-9 data. Kaplan-Meier and Cox proportional hazards tests were used for survival analyses. RESULTS For all pts, median overall survival (OS) was 17.5 mos and median distant metastasis free survival (DMFS) was 11.5 mos. The chemo then RT group had a greater proportion of pts who received FOLFIRINOX than the chemo only group (64% vs 54%, P = 0.03). The chemo then RT group also had a greater percentage of pts who went to surgery than the chemo alone group (33% vs 16%, P < 0.0001). Pts with BRPC were more likely to receive surgery than pts with LAPC (48% vs. 14%, P < 0.0001). Univariate analyses showed that baseline stage (BRPC vs LAPC), surgery, CA19-9 response, and receipt of chemo then RT were associated with both OS and DMFS. Chemo regimen was associated with OS but not DMFS on univariate analysis. Multivariate analysis identified that surgery, CA19-9 response, and receipt of chemo then RT were independent prognostic factors for both OS and DMFS (Table). Multivariate analysis of only LAPC showed the same associations with OS and DMFS as with all pts. CONCLUSION RT following chemo was associated with better OS and DMFS compared with chemo alone in a modern retrospective BRPC and LAPC cohort. Additional studies are needed to clarify the role of RT.

PURPOSE/OBJECTIVE(S) Patients with pancreatic cancer often receive radiation therapy before undergoing surgical resection. We compared the clinical outcomes differences between SBRT and 3D/IMRT after receiving current, modern standard-of-care chemotherapy. MATERIALS/METHODS We retrospectively identified patients with borderline resectable or locally advanced pancreatic cancer treated with neoadjuvant SBRT (median: 36.0Gy/5fx), 3D-CRT (median: 50.4Gy/28fx) or IMRT (median: 50.4Gy/28fx) at one institution 2015-2020. Overall survival (OS) and progression-free survival (PFS) were analyzed using COX regression. RESULTS In total, 111 patients were included. Sixty patients (54.1%) were treated with SBRT, and 51 patients (45.9%) were treated with 3D/IMRT. Patients in the SBRT group were slightly older (median age: 70.0 vs 62.7 in the 3D/IMRT group). Both groups had similar proportions of patients with locally advanced pancreatic cancer (SBRT: 32, 53.3%; 3D/IMRT: 27, 52.9%). All patients were treated with chemotherapy. Patients in the SBRT group underwent slightly more surgical resection when compared to the 3D/IMRT group (36.7% vs 21.6%, respectively, P = 0.08). At a median follow-up of 22 months, a total of 65 patients (58.6%) died: 28 (28/60, 46.7%) in the SBRT group, and 37 (37/51, 72.5%) in the 3D/IMRT group. Median OS was slightly higher in the SBRT group (28.7 months vs 24.2 months in the 3D/IMRT group). On multivariable COX regression, the choice of radiation therapy technique was not associated with differences in OS (aHR = 0.6, 95% CI [0.3-1.1], P = 0.10). Moreover, patients that underwent surgical resection had better OS (aHR = 0.3, P = 0.003). Furthermore, PFS was also similar between patients treated with SBRT and those treated with 3D/IMRT (aHR = 0.8, P = 0.31). CONCLUSION SBRT was associated with similar clinical outcomes when compared to conventional radiation techniques, despite being delivered over a shorter period of time which would spare patients prolonged treatment burden. Future prospective data are still needed to better assess the role of SBRT in patients with pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is almost uniformly fatal and characterized by early metastasis. Oncogenic KRAS mutations prevail in 95% of PDAC tumors and co-occur with genetic alterations in the TP53 tumor suppressor in nearly 70% of patients. Most p53 alterations are missense mutations that exhibit gain-of-function phenotypes that include increased invasiveness and metastasis. However, the extent of direct cooperation or synergism between KRAS effectors and mutant p53 remain undefined. To study how KRAS effectors and mutant p53 cooperate to drive PDAC development, we developed a novel somatic model that expresses mutant KRAS and p53 only in pancreas tumor cells, leaving the tumor microenvironment and immune system intact. PDAC genetically engineered mouse models (GEMMs) were generated by crossing a conditional oncogenic KRasG12D (K) allele with a conditional null p53 allele (Pfl) or a novel, conditional knock-in mutant p53R172H allele (Pwm) that selectively expresses mutant p53 in tumor cells while preserving wildtype p53 expression in all other animal cells. The incidence of metastatic lesions in the liver and lungs of KPwmC mice was over 2-fold greater (p=.03) relative to KPflC mice. Through orthogonal analyses of this model and human PDAC samples, we show that oncogenic KRAS effectors phosphorylate and activate cyclic AMP responsive element binding protein 1 (CREB1), allowing physical interactions with mutant p53 to transcriptionally upregulate the pro-metastatic transcription factor, FOXA1, which enhances β-catenin stabilization and activity. Targeting KRAS and mutant p53 cooperativity through pharmacologic inhibition of CREB1 dramatically dampens FOXA1 expression and PDAC metastasis. Our findings demonstrate a direct, mechanistic link between key oncogenic KRAS signaling elements and mutant p53 that result in a broad, multiplexed activation of cancer-associated transcriptional networks. Moreover, we identify CREB1 as a viable therapeutic strategy to undermine oncogenic KRAS and mutant p53 cooperation to mitigate PDAC metastasis. Citation Format: Michael Paul Kim, Xinqun Li, Jenying Deng, Yun Zhang, Bingbing Dai, Kendra Allton, Tara Hughes, Christian Siangco, Jithesh Augustine, Yaan Kang, Joy M. McDaniel, Shunbin Xiong, Eugene Koay, Florencia McAllister, Christopher Bristow, Timothy Heffernan, Anirban Maitra, Bin Liu, Michelle Barton, Amanda Wasylischen, Jason Fleming, Guillermina lozano. Mutant p53 and oncogenic KRAS converge on CREB1 to drive pancreatic cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2417.

Pancreatic ductal adenocarcinoma (PDAC) is an incurable disease characterized by poor survival, dense desmoplastic stroma and activating mutations in KRAS ( Citation Format: Sanjana Srinivasan, Johnathon Rose, Wantong Yao, Sahil Seth, Michael Peoples, Annette Machado, Chieh-Yuan Li, I Lin Ho, Jaewon J. Lee, Paola A. Guerrera, Eiru Kim, Mustafa Syed, Joseph Daniele, Angela K. Deem, Michael Kim, Christopher A. Bristow, Eugene Koay, Giannicola Genovese, Andrea Viale, Timothy P. Heffernan, Anirban Maitra, Traver Hart, Alessandro Carugo, Giulio Draetta. Diversity across the pancreatic ductal adenocarcinoma disease spectrum revealed by network-anchored functional genomics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2136.

Studies on melanoma brain metastases (MBM) with regard to mutational status are lacking. We investigated the outcomes of MBM in molecularly characterized patients for BRAF and NRAS mutations receiving conventional treatment. We investigated associations between outcomes [competing risk of local and distant brain failure (LF, DF) and overall survival (OS)] and clinical/pathological features of patients with known mutation status following initial treatment of MBM. Competing risk analysis was performed using the methods of Fine and Gray. We identified 235 patients with MBM diagnosed from 2005 to 2011. Mutation prevalence was BRAF non-V600K 98 (42%), BRAF V600K 34 (14%), NRAS 43 (18%), and wild-type for both genes (WT) 60 (26%) patients. Six month cumulative incidence LF rates were 3% for combined SRS or surgery with adjuvant radiation, 18% for surgery, 18% for SRS, 60% for WBRT, and 67% for systemic therapy. On multivariate analysis, only mutation status and initial treatment type were found to be independent predictors of local control. As compared to WT, NRAS (HR 2.58, 95% CI 1.18–5.67, p = 0.02) and BRAF V600K (HR 2.83, 95% CI 1.23–6.47, p = 0.01) mutational status were statistically significant while BRAF non-V600K status was not statistically significant (p = 0.23). Mutation status was not associated with DF or OS. BRAF V600K and NRAS mutation status predict increased LF following conventional treatments for MBM. These data can inform the design and interpretation of future MBM trials.