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OBJECTIVES: The innate biologic clock plays a significant role in lipid metabolism, including the peripheral clock in the pancreas. However, an evaluation of the downstream lipids in the pancreatic lipidome is lacking. We sought to understand the diurnal variations of lipids within the pancreatic lipidome. METHODS: At four weeks of age, C57Bl/6J mice were subjected to either normal lighting conditions or a chronic jetlag (CJ) condition known to mimic chronic shiftwork in humans. At nine months, mice were serially killed at 4-hour intervals over 24-hours. The pancreas was removed and subjected to untargeted liquid chromatography-mass spectrometry to examine the pancreatic lipidome. RESULTS: A total of 4.7% of the pancreatic lipidome was rhythmically expressed, which increased to 12.9% after CJ. Following CJ, there was a 4.58-hour shift in the timing of peak 24-hour lipid expression. Chronic jetlag also led to the enrichment of diacylglycerols and triglycerides, while promoting a decrease in lysophosphatidylcholines and 44-carbon acyl chain lipids. CONCLUSIONS: The pancreatic lipidome exhibits diurnal rhythmicity across a broad number of lipid classes. Chronic jetlag led to alterations in lipid composition that mirrored other metabolically active organs. Several of the reported changes may link altered sleep-wake cycles with known circadian disruption-induced pancreatic diseases.

ObjectivesThe pathogenesis of pancreas cancer (PDAC) remains poorly understood, hindering efforts to develop a more effective therapy for PDAC. Recent discoveries show the aryl hydrocarbon receptor (AHR) plays a crucial role in the pathogenesis of several cancers, and can be targeted for therapeutic effect. However, its involvement in PDAC remains unclear. Therefore, we evaluated the role of AHR in the development of PDACin vivo.MethodsWe created a global AHR-null, mutantKras-driven PDAC mouse model (A-/-KC) and evaluated the changes in PDAC precursor lesion formation (Pan-IN 1, 2, and 3) and associated fibro-inflammation between KC and A-/-KC at 5 months of age. We then examined the changes in the immune microenvironment followed by single-cell RNA-sequencing analysis to evaluate concomitant transcriptomic changes.ResultsWe found a significant increase in PanIN-1 lesion formation and PanIN-1 associated fibro-inflammatory infiltrate in A-/-KC vs KC mice. This was associated with significant changes in the adaptive immune system, particularly a decrease in the CD4+/CD8+ T-cell ratio, as well as a decrease in the T-regulatory/Th17 T-cell ratio suggesting unregulated inflammation.ConclusionThese findings show the loss of AHR results in heightenedKras-induced PanIN formation, through modulation of immune cells within the pancreatic tumor microenvironment.

Disruption of the circadian clock is linked to cancer development and progression. Establishing this connection has proven beneficial for understanding cancer pathogenesis, determining prognosis, and uncovering novel therapeutic targets. However, barriers to characterizing the circadian clock in human pancreas and human pancreatic cancer – one of the deadliest malignancies – have hindered an appreciation of its role in this cancer. Here, we employed normalized coefficient of variation (nCV) and clock correlation analysis in human population-level data to determine the functioning of the circadian clock in pancreas cancer and adjacent normal tissue. We found a substantially attenuated clock in the pancreatic cancer tissue. Then we exploited our existing mouse pancreatic transcriptome data to perform an analysis of the human normal and pancreas cancer samples using a machine learning method, cyclic ordering by periodic structure (CYCLOPS). Through CYCLOPS ordering, we confirmed the nCV and clock correlation findings of an intact circadian clock in normal pancreas with robust cycling of several core clock genes. However, in pancreas cancer, there was a loss of rhythmicity of many core clock genes with an inability to effectively order the cancer samples, providing substantive evidence of a dysregulated clock. The implications of clock disruption were further assessed with aBmal1knockout pancreas cancer model, which revealed that an arrhythmic clock caused accelerated cancer growth and worse survival, accompanied by chemoresistance and enrichment of key cancer-related pathways. These findings provide strong evidence for clock disruption in human pancreas cancer and demonstrate a link between circadian disruption and pancreas cancer progression.Author SummaryThe circadian clock is a regulator of human homeostasis. Dysfunction of the clock can lead to the development of diseases, including cancer. Although several cancers have been shown to have a dysfunctional clock which may alter prognosis or change treatment, this has been suggested but not demonstrated in pancreatic cancer. Investigation of this link is important because pancreatic cancer is highly lethal with few effective treatment options. Here we use recently pioneered bioinformatics approaches to assess clock functionality in human pancreatic cancer specimens, where we demonstrate that the clock is dysfunctional relative to normal pancreatic tissue. We then knocked out the core clock gene,Bmal1, in pancreatic cancer cells, which led to faster tumor growth and worse survival in mice and enhanced chemotherapeutic resistance to standard chemotherapy agents used in the treatment of pancreatic cancer. Collectively, our findings establish human pancreatic cancer as having clock dysfunction and clock dysfunction causing a more aggressive cancer.

Background and objectives Prognostic nomograms for patients undergoing resection of retroperitoneal sarcoma (RPS) include the Sarculator and Memorial Sloan Kettering (MSK) sarcoma nomograms. We sought to validate the Sarculator and MSK nomograms within a large, modern multi-institutional cohort of patients with primary RPS undergoing resection. Methods Patients who underwent resection of primary RPS between 2000 and 2017 across nine high-volume US institutions were identified. Predicted 7-year disease-free (DFS) and overall survival (OS) and 4-, 8-, and 12-year disease-specific survival (DSS) were calculated from the Sarculator and MSK nomograms, respectively. Nomogram-predicted survival probabilities were stratified in quintiles and compared in calibration plots to observed survival outcomes assessed by Kaplan-Meier estimates. Discriminative ability of nomograms was quantified by Harrell's concordance index (C-index). Results Five hundred and two patients underwent resection of primary RPS. Histologies included leiomyosarcoma (30%), dedifferentiated liposarcoma (23%), and well-differentiated liposarcoma (15%). Median tumor size was 14.0 cm (interquartile range [IQR], 8.5-21.0 cm). Tumor grade distribution was: Grade 1 (27%), Grade 2 (17%), and Grade 3 (56%). Median DFS was 31.5 months; 7-year DFS was 29%. Median OS was 93.8 months; 7-year OS was 51%. C-indices for 7-year DFS, and OS by the Sarculator nomogram were 0.65 (95% confidence interval [CI]: 0.62-0.69) and 0.69 (95%CI: 0.65-0.73); plots demonstrated good calibration for predicting 7-year outcomes. The C-index for 4-, 8-, and 12-year DSS by the MSK nomogram was 0.71 (95%CI: 0.67-0.75); plots demonstrated similarly good calibration ability. Conclusions In a diverse, modern validation cohort of patients with resected primary RPS, both Sarculator and MSK nomograms demonstrated good prognostic ability, supporting their ongoing adoption into clinical practice.

Misalignment of the circadian clock compared to environmental cues causes circadian desynchrony, which is pervasive in humans. Clock misalignment can lead to various pathologies including obesity and diabetes, both of which are associated with pancreatic ductal adenocarcinoma - a devastating cancer with an 80% five-year mortality rate. Although circadian desynchrony is associated with an increased risk of several solid-organ cancers, the correlation between clock misalignment and pancreas cancer is unclear. Using a chronic jetlag model, we investigated the impact of clock misalignment on pancreas cancer initiation in mice harboring a pancreas-specific activatedKrasmutation. We found that chronic jetlag accelerated the development of pancreatic cancer precursor lesions, with a concomitant increase in precursor lesion grade. Cell-autonomous knock-out of the clock in pancreatic epithelial cells ofKras-mutant mice demonstrated no acceleration of precursor lesion formation, indicating non-cell-autonomous clock dysfunction was responsible for the expedited tumor development. Therefore, we applied single-cell RNA sequencing over time and identified fibroblasts as the cell population manifesting the greatest clock-dependent changes, with enrichment of specific cancer-associated fibroblast pathways due to circadian misalignment. Collectively, these results suggest fibroblasts as the putative target of chronic jetlag-induced accelerated pancreas cancer initiation.

Despite standardization, the 2016 ISGPF criteria are limited by their wider applicability and oversimplification of grade B POPF. This work applied the 2016 ISGPF grading criteria within a US academic cancer center to verify clinical and fiscal distinctions and sought to improve grading criteria for grade B POPF. The 2008–2018 cost and NSQIP data from pancreaticoduodenectomy to postoperative day 90 were merged. All POPFs were coded by 2016 ISGPF criteria. The Clavien-Dindo Classification (CD) defined complication severity. On sub-analyses, grade B POPFs were divided into those with adequate drainage and those requiring additional drainage. Chi-square, ANOVA, and Fisher’s least significant difference test were employed. Two hundred thirty-two patients were in the final analyses, 72 (31%) of whom had POPFs: 16 (7%) biochemical leaks, 54 (23%) grade B (28% required additional drainage), and 2 (1%) grade C. There was no significant difference in length of stay, CD, readmission, or cost in patients without a POPF, with biochemical leak or grade B POPF. On sub-analyses, 92% of adequately drained grade B POPFs had CD 1–2 and readmission equivalent to patients without POPF (p > 0.05). One hundred percent of grade B POPF requiring drainage had CD 3–4a, and 67% were readmitted. Cost was significantly increased in grade B POPF requiring additional drainage (p = 0.02) and grade C POPF (p

The substantial cost of care for patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy can be augmented by changes in practice patterns. This report discusses the recent publication of the authors' group and their thoughts on cost-conscious cancer care.

BACKGROUND: Physician variation in adherence to best practices contributes to the high costs of health care. Understanding surgeon-specific cost variation in common surgical procedures may inform strategies to improve the value of surgical care. METHODS: Laparoscopic cholecystectomies at a single institution were identified over a five-year period and linked to an institutional cost database. Multiple linear regression was used to control for patient-, case-, and hospital- specific factors while assessing the impact of surgeon variability on cost. RESULTS: The final dataset contained 1,686 patients. Higher surgeon volume (reported in tertiles) was associated with decreased costs ($5,354 vs $6,301 vs $7,156, p

Background Automated data extraction from the electronic medical record is fast, scalable, and inexpensive compared with manual abstraction. However, concerns regarding data quality and control for underlying patient variation when performing retrospective analyses exist. This study assesses the ability of summary electronic medical record metrics to control for patient-level variation in cost outcomes in pancreaticoduodenectomy. Methods Patients that underwent pancreaticoduodenectomy from 2014 to 2018 at a single institution were identified within the electronic medical record and linked with the National Surgical Quality Improvement Program. Variables in both data sets were compared using interrater reliability. Logistic and linear regression modelling of complications and costs were performed using combinations of comorbidities/summary metrics. Models were compared using the adjusted R2 and Akaike information criterion. Results A total of 117 patients populated the final data set. A total of 31 (26.5%) patients experienced a complication identified by the National Surgical Quality Improvement Program. The median direct variable cost for the encounter was US$14,314. Agreement between variables present in the electronic medical record and the National Surgical Quality Improvement Program was excellent. Stepwise linear regression models of costs, using only electronic medical record–extractable variables, were non-inferior to those created with manually abstracted individual comorbidities (R2 = 0.67 vs 0.30, Akaike information criterion 2,095 vs 2,216). Model performance statistics were minimally impacted by the addition of comorbidities to models containing electronic medical record summary metrics (R2 = 0.67 vs 0.70, Akaike information criterion 2,095 vs 2,088). Conclusion Summary electronic medical record perioperative risk metrics predict patient-level cost variation as effectively as individual comorbidities in the pancreaticoduodenectomy population. Automated electronic medical record data extraction can expand the patient population available for retrospective analysis without the associated increase in human and fiscal resources that manual data abstraction requires.

Background Elevations in inflammatory biomarkers, including neutrophil-to-lymphocyte ratio (NLR) or platelet-to-lymphocyte ratio (PLR), are reportedly associated with decreased overall survival (OS) or recurrence-free survival (RFS) in patients with numerous cancers. A large multicenter sarcoma data set was used to determine if elevated NLR or PLR was associated with worse survival and can guide treatment selection. Materials and methods A total of 409 patients with a primary retroperitoneal sarcoma (n = 268) or truncal (n = 141) sarcoma from 2000 to 2015 were analyzed using the US Sarcoma Collaboration database. Binary NLR and PLR values were developed using receiver operating characteristic curves. Kaplan-Meier model and Cox proportional hazards model identified predictors of decreased OS and RFS. Point biserial analyses were used to correlate binary and continuous data. Results Neither elevated NLR nor PLR was predictive of decreased OS or RFS. These findings persisted despite exclusion of comorbid inflammatory conditions. Further, NLR and PLR were not correlated with tumor grade. In multivariate models, decreased RFS was associated with tumor factors (e.g., positive margins, tumor grade, tumor size, necrosis, positive nodes); decreased OS was associated with histologic subtype, male gender, and nodal involvement. Conclusions Although several small studies have suggested that elevated NLR and PLR are associated with decreased survival in patients with abdominal or truncal sarcoma, this large multicenter study demonstrates no association with decreased OS, decreased RFS, or tumor grade. Rather, survival outcomes are best predicted using previously established tumoral factors.

INTRODUCTION. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is utilized for peritoneal malignancies and is associated with significant resource use. To address potentially modifiable factors contributing to excessive cost, we sought to determine predictors of high cost of care for patients undergoing CRS/HIPEC. METHODS. An institutional CRS/HIPEC database was queried for adult patients from 2014 to 2018. Cost was defined as cost for the index hospitalization, and high-cost cases were defined as > 75th percentile for cost. Bivariate analyses for cost were performed, and all significant tumor, patient, and surgeon-specific variables were entered in a linear regression for cost. A separate linear regression was performed for length of stay (LOS). RESULTS. In total, 59 patients underwent 61 CRS/HIPEC procedures. The median direct variable cost was $20,509 (16,395–25,240). Median length of stay (LOS) was 8 (7–11.5) days and ICU stay was 1 (1–1.5) day. LOS, length of ICU stay and operative time were predictive of cost. Factors associated with increased LOS were Clavien-Dindo grade II complications and ostomy creation. Patient-related factors, including age and BMI, tumor-related factors, such as PCI and CCR, and surgeon were not predictive of cost nor LOS. DISCUSSION. Our results, the first to identify predictors of high cost of CRS/HIPEC-related care in the US, reveal cost was largely related to length and intensity of care. In turn, these drivers were influenced by complications and operative factors. Future work will focus on identifying an appropriate ERAS protocol following CRS/HIPEC and selection of those patients that may avoid routine ICU admission.

OBJECTIVE: To determine differences in Entrustable Professional Activity (EPA) assessments between male and female general surgery residents. SUMMARY BACKGROUND DATA: Evaluations play a critical role in career advancement for physicians. However, female physicians in training receive lower evaluations and underrate their own performance. Competency-based assessment frameworks, such as EPAs, may help address gender bias in surgery by linking evaluations to specific, observable behaviors. METHODS: In this cohort study, EPA assessments were collected from July 2018 to May 2020. The effect of resident gender on EPA entrustment levels was analyzed using multiple linear and ordered logistic regressions. Narrative comments were analyzed using Latent Dirichlet Allocation (LDA) to identify topics correlated with resident gender. RESULTS: Of the 2,480 EPAs, 1,230 EPAs were submitted by faculty and 1,250 were submitted by residents. After controlling for confounding factors, faculty evaluations of residents were not impacted by resident gender (estimate = 0.09, p = 0.08). However, female residents rated themselves lower by 0.29 (on a 0–4 scale) compared to their male counterparts (p < 0.001). Within narrative assessments, topics associated with resident gender demonstrated that female residents focus on the ‘guidance’ and ‘supervision’ they received while performing an EPA, while male residents were more likely to report ‘independent’ action. CONCLUSIONS: Faculty assessments showed no difference in EPA levels between male and female residents. Female residents rate themselves lower by nearly an entire PGY level compared to male residents. LDA-identified topics suggest this difference in self-assessment is related to differences in perception of autonomy.

Background The use of radiation therapy in the treatment of retroperitoneal sarcomas has increased in recent years. Its impact on survival and recurrence is unclear. Methods A retrospective propensity score matched (PSM) analysis of patients with primary retroperitoneal soft tissue sarcomas, who underwent resection from 2000 to 2016 at eight institutions of the US Sarcoma Collaborative, was performed. Patients with metastatic disease, desmoid tumors, and palliative resections were excluded. Results Total 425 patients were included, 56 in the neoadjuvant radiation group (neo-RT), 75 in the adjuvant radiation group (adj-RT), and 294 in the no radiotherapy group (no-RT). Median age was 59.5 years, 186 (43.8%) were male with a median follow up of 31.4 months. R0 and R1 resection was achieved in 253 (61.1%) and 143 (34.5%), respectively. Overall 1:1 match of 46 adj-RT and 59 neo-RT patients was performed using histology, sex, age, race, functional status, tumor size, grade, resection status, and chemotherapy. Unadjusted recurrence-free survival (RFS) was 35.9 months (no-RT) vs 33.5 months (neo-RT) and 27.2 months (adj-RT), P = .43 and P = .84, respectively. In the PSM, RFS was 17.6 months (no-RT) vs 33.9 months (neo-RT), P = .28 and 19 months (no-RT) vs 27.2 months (adj-RT), P = .1. Conclusions Use of radiotherapy, both in adjuvent or neoadjuvent setting, was not associated with improved survival or reduced recurrence rate.

OBJECTIVE: To compare the survival outcomes associated with clinical and pathological response in pancreatic ductal adenocarcinoma (PDAC) patients receiving neoadjuvant chemotherapy (NAC) with FOLFIRINOX (FLX) or gemcitabine/nab-paclitaxel (GNP) followed by curative-intent pancreatectomy. BACKGROUND: Newer multiagent NAC regimens have resulted in improved clinical and pathological responses in PDAC; however, the effects of these responses on survival outcomes remain unknown. METHODS: Clinicopathological and survival data of PDAC patients treated at 7 academic medical centers were analyzed. Primary outcomes were overall survival (OS), local recurrence-free survival (L-RFS), and metastasis-free survival (MFS) associated with biochemical (CA 19–9 decrease ≥50% vs

Background Management of Sphincter of Oddi Dysfunction (SOD) requires advanced techniques (endoscopic retrograde cholangiopancreatography via gastrostomy [GERCP]) after Roux-en-Y gastric bypass (RYGB) for obesity. Transduodenal sphincteroplasty (TS) is also performed yet carries the risks of surgery. We hypothesized that TS would have increased morbidity and mortality but provide a more durable remission of symptoms. Methods All patients between 2005 and 2016 with RYGB for obesity undergoing endoscopic or surgical management for type I or II SOD were included in the study. Patients with type III SOD, or who underwent RYGB for nonobesity indications, were excluded. Results Thirty-eight patients were identified. GERCP was initially performed in 17 patients, whereas TS was performed in 21. Thirty-day mortality was 0% in our cohort, and 30-d morbidity was similar between GERCP and TS (29% versus 10%; P = 0.207). Resolution of symptoms after initial therapy was seen in 41% of GERCP (7/17) and 67% of TS (14/21) (P = 0.190), respectively, and overall after 35% (8/23) and 64% (16/24) of procedures performed (P = 0.042). Symptom resolution, as defined by the median ratio of days of total remission by total days of observed follow-up, was shorter after initial and all interventions with GERCP compared with TS (0.67 versus 1.00, P = 0.036 and 0.52 versus 1.00, P = 0.028, respectively). Conclusions Endoscopic and surgical treatment of SOD had similar morbidity and mortality. However, treatment success and duration of remission was higher in those treated with surgery.

Despite standardization, the 2016 ISGPF criteria are limited by their wider applicability and oversimplification of grade B POPF. This work applied the 2016 ISGPF grading criteria within a US academic cancer center to verify clinical and fiscal distinctions and sought to improve grading criteria for grade B POPF.The 2008-2018 cost and NSQIP data from pancreaticoduodenectomy to postoperative day 90 were merged. All POPFs were coded by 2016 ISGPF criteria. The Clavien-Dindo Classification (CD) defined complication severity. On sub-analyses, grade B POPFs were divided into those with adequate drainage and those requiring additional drainage. Chi-square, ANOVA, and Fisher's least significant difference test were employed.Two hundred thirty-two patients were in the final analyses, 72 (31%) of whom had POPFs: 16 (7%) biochemical leaks, 54 (23%) grade B (28% required additional drainage), and 2 (1%) grade C. There was no significant difference in length of stay, CD, readmission, or cost in patients without a POPF, with biochemical leak or grade B POPF. On sub-analyses, 92% of adequately drained grade B POPFs had CD 1-2 and readmission equivalent to patients without POPF (p 0.05). One hundred percent of grade B POPF requiring drainage had CD 3-4a, and 67% were readmitted. Cost was significantly increased in grade B POPF requiring additional drainage (p = 0.02) and grade C POPF (p 0.01).This analysis did not confirm an incremental increase in morbidity and cost with POPF grade. Sub-analyses enabled accurate clinical and cost distinctions in grade B POPF; adequately drained grade B POPF are low risk and clinically insignificant.

INTRODUCTION: National Comprehensive Cancer Network guidelines recommend that sentinel lymph node biopsy (SLNB) be discussed with patients with thin melanoma at higher risk for lymph node metastasis (T1b or T1a with positive deep margins, lymphovascular invasion, or high mitotic index). We examined the association between SLNB and resource utilization in this cohort. METHODS: We conducted a retrospective cohort study of patients that underwent wide local excision for higher risk thin melanomas from 2009 to 2018 at a tertiary care center. Patients who underwent SLNB were compared to those who did not undergo SLNB with regard to resource utilization, including total hospital cost. RESULTS: A total of 70 patients were included in the analysis and 50 patients (71.4%) underwent SLNB. SLNB was associated with increased hospital costs ($6700 vs. $3767; p < .01) and increased operative time (68.5 vs. 36.0 min; p < .01). This cost difference persisted in multivariable regression (p < .01). Of patients who underwent successful SLN mapping, 3 out of 49 patients had a positive SLN (6.1%). The cost to identify a single positive sentinel lymph node (SLN) was $47,906. CONCLUSION: In patients with a higher risk of thin melanoma, SLNB is associated with increased cost despite a low likelihood of SLN positivity. These data better inform patient-provider discussions as the role of SLNB in thin melanoma evolves.

BACKGROUND: Nephrectomy is often required during en bloc resection of a retroperitoneal sarcoma (RPS) to achieve an R0/R1 resection. The impact of nephrectomy on postoperative renal function in this patient population, who may also benefit from subsequent nephrotoxic systemic therapy, is not well described. METHODS: The United States Sarcoma Collaborative (USSC) database was queried for patients undergoing RPS resection between 2000–2016. Patients missing pre- or postoperative measures of renal function were excluded. A matched cohort was created using coarsened exact matching. Weighted logistic regression was used to further control for differences in the nephrectomy vs non-nephrectomy cohorts. Primary outcomes included postoperative acute kidney injury (AKI), acute renal failure (ARF), and dialysis. RESULTS: The initial cohort consisted of 858 patients, of which 3 patients (0.3%) required postoperative dialysis. The matched cohort consisted of 411 patients of which 108 patients (26%) underwent nephrectomy. Patients that underwent nephrectomy had higher rates of postoperative AKI (14.8% vs 4.3%, p

BACKGROUND: The ACS-NSQIP risk calculator predicts perioperative risk. This study tested the calculator’s ability to predict risk for outcomes following retroperitoneal sarcoma (RPS) resection. METHODS: The United States Sarcoma Collaborative database was queried for adults who underwent RPS resection. Estimated risk for outcomes was calculated twice in the risk calculator, once using sarcoma-specific CPT codes and once using codes indicative of most comorbid organ resection (e.g. nephrectomy). ROC curves were generated, with area under the curve (AUC) and Brier scores reported to assess discrimination and calibration. An AUC < 0.6 was considered ineffective discrimination. A negative ▲ Brier indicated improved performance relative to baseline outcome rates. RESULTS: In total, 482 patients were identified with a 42.3% 90-day complication rate. Discrimination was poor for all outcomes except “all complications” and “renal failure”. Baseline outcome rates were better predictors than calculator estimates except for “discharge to nursing or rehab facility” and “renal failure”. Replacing sarcoma-specific CPT codes with resection-specific codes did not improve performance. CONCLUSION: The ACS-NSQIP risk calculator poorly predicted outcomes following RPS resection. Changing sarcoma-specific CPT to resection-specific codes did not improve performance. Comorbidities in the calculator may not effectively capture perioperative risk. Future work should evaluate a sarcoma-specific calculator.

Introduction Previous studies on readmission cost in pancreaticoduodenectomy patients use estimated cost data and do not delineate etiology or cost differences between early and late readmissions. We sought to identify relationships between postoperative complication type and readmission timing and cost in pancreaticoduodenectomy patients. Methods Hospital cost data from date of discharge to postoperative day 90 were merged with 2008–2018 NSQIP data. Early readmission was within 30 days of surgery, and late readmission was 30 to 90 days from surgery. Regression analyses for readmission controlled for patient comorbidities, complications, and surgeon. Results Of 230 patients included, 58 (25%) were readmitted. The mean early and late readmission costs were $18,365 ± $20,262 and $24,965 ± $34,435, respectively. Early readmission was associated with index stay deep vein thrombosis (p

Evidence suggests that operative delay of up to 24 h is not associated with adverse outcomes among patients undergoing emergent appendectomy. However, the fiscal implication of operative delay is not well described in adults. We sought to examine the effect of delayed appendectomy on clinical outcomes and hospital cost.We conducted a retrospective cohort study of patients undergoing nonelective laparoscopic appendectomy from 2014 to 2018 at both a tertiary care center and an affiliated short-stay hospital. Using a unique data set constructed from merged electronic health record and patient-level hospital financial data, patients with delayed surgery, defined as 12 h from emergency department (ED) arrival to operation, were compared with patients who underwent surgery within 12 h. Patient-specific variables were analyzed for their association with resource utilization, and subsequent multivariable linear regression was performed for total hospital cost.1372 patients underwent laparoscopic appendectomy during the study period. 938 patients (68.3%) underwent surgery within 12 h of ED arrival, and 434 patients (31.6%) underwent delayed surgery. Delayed cases had longer length of stay (44.6 ± 42.5 versus 34.5 ± 36.5 h, P 0.01) and increased total hospital cost ($9326 ± 4691 versus $8440 ± 3404, P 0.01). The cost difference persisted on multivariable analysis (P 0.01). There were no significant differences between delayed cases and nondelayed cases for operative time, intraoperative findings, including rate of perforation, or postoperative complications.Although safe, delayed appendectomy is associated with an increased length of stay and increased total hospital costs compared with appendectomy within 12 h of reaching the ED.

IMPACT: Circadian disruption is known to cause significant human pathology but has not been evaluated in pancreas cancer carcinogenesis; through understanding how disruption of circadian rhythms can lead to pancreas cancer development and spread, preventive and therapeutic strategies can be devised. OBJECTIVES/GOALS: Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer due to early spread and poor response to therapy. Identifying factors driving PDAC growth could lead to new therapeutic strategies. Thus, we evaluated the extent to which circadian rhythm disruption, a factor strongly associated with cancer formation, contributes to PDAC pathogenesis. METHODS/STUDY POPULATION: To achieve the objective, we evaluated mice with pancreas lineage Kras-mutation (KC mice), which are predisposed to develop the full spectrum of pancreas cancer precursor lesions (pancreatic intra-epithelial neoplasia or PANIN-1, 2, 3) and PDAC. We subjected KC mice to a light-dark phase shift protocol known to induce circadian disruption (KCCD, n = 18), and another group to standard lighting conditions (KCNC, n = 31), with equal numbers of males and females in each group. The mice were allowed access to food and water ad libitum until sacrifice at age 9 months. Histopathologic evaluation of the pancreas was then performed to assess for pancreatic inflammation, pancreatic precursor lesions (PANIN) and PDAC. Fisher’s Exact Test was used to evaluate differences in incidence. RESULTS/ANTICIPATED RESULTS: As expected, both groups of mice demonstrated 100% incidence of chronic pancreatitis and PANIN-1 (low-grade precursor lesion) at age 9 months. This is consistent with the KC phenotype. However, the KCCD mice demonstrated a significant increase in acute pancreatic inflammation (61.1% vs 19.4%, p = 0.005) compared to KCNC mice. Furthermore, intermediate grade precursor lesions (PANIN-2) were also significantly increase in the KCCD mice (38.9% vs 6.5%, p = 0.006). Incidence of high-grade precursor lesions (PANIN-3, or carcinoma in situ: 22.2% vs 9.7%) and PDAC (27% vs 19%) were also increased, but these were not statistically significant. These results are notable given the established progression from higher grade premalignant PANIN lesions (PANIN-2, PANIN-3) to PDAC. DISCUSSION/SIGNIFICANCE OF FINDINGS: Insight into how circadian disruption leads to increased PANIN-2 formation and increase in acute inflammation may be advantageous for understanding circadian disruption in PDAC carcinogenesis. The circadian clock is present in immune cells and disruption can induce immune dysregulation. This mechanism will be evaluated in follow up studies.

The comprehensive management of gallbladder disease includes not only understanding the principles of safe cholecystectomy, intraoperative cholangiography, and bile duct exploration but also the familiarity of the current endoscopic and surgical therapies for the known associated morbidities and special scenarios. In this chapter, we will review several advanced biliary procedures including both endoscopic and minimally invasive surgical bilioenteric anastomoses as well as transduodenal sphincteroplasty with contemporary approaches, indications, technical description, and existing supportive evidence.

Background. Retroperitoneal sarcomas (RPS) comprise approximately 15% of all soft-tissue sarcomas and frequently associated with significant morbidity and as little as 30% 5-year survival. Here, we provide a large, contemporary, and multi-institutional experience to determine which tumor, patient, and treatment characteristics are associated with long-term outcomes in RPS. Methods. 571 patients with primary RPS were identified from the United States Sarcoma Collaboration (USSC). RPS patients who underwent resection from January 2000 to April 2016 were included with patient, tumor, and treatment-specific variables investigated as independent predictors of survival. Survival analyses for disease-free and overall survival were conducted using Kaplan–Meier and Cox proportional hazards model methods. Results. The study cohort was 55% female, with a median age of 58.9 years (IQR: 48.6–70.0). The most common tumor histiotypes were liposarcoma (34%) and leiomyosarcoma (28%). Median follow-up was 30.6 months (IQR: 11.2–60.4). Median disease-free survival was 35.3 months (95% CI: 27.6–43.0), with multivariate predictors of poorer disease-free survival including higher grade tumors, nodal-positive disease, and multivisceral resection. Median overall survival was 81.6 months (95% CI: 66.3–96.8). Multivariate predictors of shorter overall survival included higher grade tumors, nodal-positive and multifocal disease, systemic chemotherapy, and grossly positive margins (R2) following resection. Conclusions. The strongest predictors of disease-free and overall survival are tumor-specific characteristics, while surgical factors are less impactful. Nonsurgical therapies are not associated with improved outcomes despite persistent interest and utilization. Complete macroscopic resection (R0/R1) remains a persistent potentially modifiable risk factor associated with improved overall survival in patients with retroperitoneal sarcomas.

Cell culture is a powerful tool for investigation. For the surgeon scientist, it may offer a shorter turnaround time in test results, a cheaper model than other in vivo methods (e.g., large animal models), and can offer the specificity that comes with isolating a cellular process. Suffice it to say that it is an invaluable skill to have when starting a lab. In this chapter we introduce why cell cultures make sense for the surgeon scientist, how to go about thinking about cell cultures, and tips and tricks to getting started with this technology. Many theoretical examples are used to solidify certain concepts, and procedural protocols are included to get you started. These are certainly not a comprehensive analysis of everything that is needed in the lab; however, it is a solid background for those wishing to begin their career as a surgeon scientist.

Introduction: Emerging data suggest a role for circadian disruption in tumor formation and progression. Yet little is known regarding the effects of circadian disruption on the oncogenesis of pancreatic ductal adenocarcinoma (PDAC). We sought to determine if circadian disruption enhances PDAC development through a genetically engineered mouse model, and evaluate possible mechanisms with transcriptomic analysis. Methods: KrasG12D/+ mice (K) were crossed with Pdx-1 Cre (C) mice on a C57BL/6 background to generate KC mice. At 4 weeks, mice were subjected to standard lighting conditions (KC normal circadian [KCNC]) or a chronic jet-lag protocol known to induce circadian disruption (KCCD), with light/dark cycles shifted 8 hours every 2-3 days. Mice were sacrificed at 9 months for histologic analysis, examining for PDAC and its precursor lesions (PanINs). Comparisons were made with Fischer's Exact Test. For pancreatic transcriptomic profiling, 144 4-week-old wild-type (WT) C57BL/6 mice underwent disruption (WTCD, n = 72) or standard lighting conditions (WTNC, n = 72) for 4 weeks to identify cycling genes over a 48 hour period. Four weeks was chosen to understand the effects of disruption on gene expression impacting tumor initiation. Standard gene cycling analysis was performed with meta2d utilizing a false discovery rate of q = 0.1, and comparisons were made with the Audic-Claverie Distribution tool. Results: All KC mice (27 KCNC & 7 KCCD) exhibited chronic pancreatitis and PanIN-1 (p = 1). However, KCCD mice developed higher rates of acute pancreatitis (86% vs 4%; p < 0.01) and PanIN-2 (43% vs 7%; p = 0.04) versus KCNC mice. PanIN-3 (14% vs 7% p = 0.48) and PDAC (29% vs 16% p = 0.6) were also increased but did not reach statistical significance. Given this phenotype, we sought a mechanism through transcriptomic analysis. In total, we found 12.8% of the protein-coding pancreatic transcriptome was cycling in either WTNC or WTCD. Pathway enrichment analysis demonstrated genes important for circadian rhythm were cycling in WTNC, while those important for catabolism and protein localization were cycling in WTCD. Only 129 genes, shared between male and female mice, exclusively cycled following circadian disruption. Of those, roughly 15% have been implicated in PDAC development, reported as prognostic biomarkers in PDAC or possibly contribute to chemotherapeutic resistance in PDAC. Conclusion: Little is known about the effects of circadian disruption on PDAC. We have demonstrated histopathologic evidence of an increased incidence of pancreatic inflammation and pathogenic lesions following circadian disruption. Transcriptomic analysis of wild-type pancreas revealed an increased number of cycling genes involved in energy production following disruption. Future work will investigate the candidate genes identified to ascertain how circadian disruption leads to increased development of pancreatic lesions. Citation Format: Patrick Beard Schwartz, Morgan Walcheck, Noah D. Carrillo, Kristina A. Matkowskyj, Christopher A. Bradfield, Sean Ronnekleiv-Kelly. Circadian disruption enhances development of pancreatic inflammation and pancreatic cancer precursors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3811.

Aggressive en bloc resection of adjacent organs is often necessary to resect pancreatic or colonic lesions. However, it is debated whether simultaneous pancreatectomy with colectomy (P+C) is warranted as it potentially increases morbidity and mortality (MM). We hypothesized that MM would be increased in P+C, especially in cases of pancreatitis. All patients who underwent pancreatectomy (P) and simultaneous pancreatectomy with colectomy (P+C) at a high-volume center from November 2006 to 2015 were prospectively collected using ACS-NSQIP at our institution. Patients with additional multivisceral or enucleation procedures were excluded. Data were augmented to 90-day outcomes using our institutional database. Forty-three patients with a mean age of 62 years (27:16 male: female) underwent P+C, accounting for 2.39% (43/1797) of pancreatectomies performed. Pancreatoduodenectomy (PD) was performed in 61% (n = 26), distal pancreatectomy (DP) in 37% (n = 16), and total pancreatectomy (TP) in 2% (n = 1) of patients. The 30- and 90-day MM were higher in P+C than P (30-day: 54 vs. 37%, p = 0.037 and 9 vs. 2%, p = 0.022; 90-day: 61 vs. 42%, p = 0.019 and 14 vs. 3%, p = 0.002). Logistical regression modeling revealed an association between 90-day mortality and colectomy (p = 0.013, OR = 3.556). When P+C MM were analyzed according to intraoperative factors, there was no significant difference according to type of pancreatectomy (PD vs. DP vs. TP), origin of primary lesion (pancreas vs. colon), surgical indication (malignant vs. non-malignant), or case status (planned colectomy vs. intraoperative decision). Addition of colectomy to pancreatectomy substantially increased MM. Subanalysis revealed that type of resection performed, etiology, and planning status did not account for increased risk when performing P+C. However, colectomy was found to be an independent risk factor for mortality. Therefore, patients should be informed of the risk of increased postoperative complications until a further study can identify potential patients or perioperative factors that can be used for risk stratification.

The alpha 7 (α7) subtype of nAChR appears to play critical roles in learning, cognition, and various neuropathologies including nicotine addiction. Nicotine-upregulation of α7 Rs may play a significant role in the latter phenomenon. But whether nicotine-upregulation of α7 Rs reliably occurs, and its underlying mechanism(s), are largely unknown. Previous studies of α7 nAChRs heterologously expressed in Xenopus oocytes failed to observe nicotine-upregulation. These failures might have been due to intracellular accumulation of nicotine and its subsequent slow release from oocytes, resulting in desensitization of α7 Rs during functional assays. In our experiments, 12-14 hr exposure to nicotine (100 μM) 4-5 days post cRNA-injection (PI), followed by extensive washout, yielded statistically-significant ∼2-fold increases in peak α7 currents and net charge as determined by TEVC and α7-protein (by Western blot). Less-extensive washout, as well as 100 nM nicotine incubation, failed to produce upregulation. Instead, inactivated/desensitized currents were observed. GC/MS measurement of nicotine in the washout fluid confirmed that nicotine was continually released from oocytes. The concentration was ∼20 nM at 3-4 hr following washout onset, well in excess of the ∼ 3 nM IC50 value. Exposure of α7-expressing oocytes to cumulative washout fluid produced suppressed α7 currents (∼ 8% of controls). Similar to nicotine, methyllycaconitine, a cell-permeable competitive antagonist of α7 Rs, and carbachol, a stable membrane-impermeable agonist, also produced ∼ 2X-upregulation. However, ACh incubation (which can be hydrolyzed by the oocytes) failed to produce upregulation. We also found that chelation of intracellular Ca2+ by BAPTA-AM completely blocked nicotine upregulation. However, elimination of extracellular Ca2+ had no effect. These results suggest that persistent ligand-binding to α7 Rs (but not necessarily channel gating), leading to increases in [Ca2+]i, was critical for α7 R-upregulation. Several Ca2+-dependent signaling pathways were implicated in nicotine-upregulation of α7.

We have identified several distinct mechanisms by which inhibitors of tyrosine kinases (genistein) and calcineurin/PP2B (cyclosporine A, CsA) produce functional upregulation of α7 Rs expressed in Xenopus oocytes. These effects varied with the duration of drug exposure and time course of expression. Genistein's potentiation of peak currents was greater early in expression (2 vs. 5 days following α7-cRNA injection), and for prolonged drug exposures (24 hr vs 1 min). CsA's potentiation was limited to 24 hr exposure and was independent of expression time. When combined 5-days post-injection, genistein and CsA produced a facilitation greater than either alone: 5-6 fold for CsA + 1 min genistein vs. 2.6-fold for CsA and 2.3-fold for 1 min genistein; 8.5 fold for CsA + 24 hr genistein vs. 2.6 fold for CsA and 4.3 fold for 24 hr genistein. Similarly, 2-days following cRNA injections, 24 hr CsA plus 1 min genistein produced facilitation greater than either alone: 4.5 fold vs. 1.5 for CsA and 2.8 for genistein. However, the combination of CsA and genistein (24 hr) produced facilitation (5.3 fold) that was less than genistein alone: 1.5 for CsA, and 12 for genistein. We propose a model to explain this pattern that assumes: 1) 1 min genistein's effects are exclusively PAM, while 24 hr genistein's effects are PAM and non-PAM (all effects are positive), 2) the effects of CsA alone are net positive, but reflect two opposing processes. CsA facilitates currents by increasing surface membrane numbers of α7-Rs and/or single-channel gating. But CsA also inhibits cRNA-translation and/or chaperoning of α7-Rs. The inhibitory effect is greater early in expression, reducing the number of functional α7-Rs distal to the ER/Golgi pathway that genistein can positively interact with.

Several previous studies that explored tyrosine phosphorylation/dephosphorylation-involvement in functional upregulation of α7-nAChRs found that genistein, a broad-spectrum inhibitor of protein tyrosine kinases (PTKs), increased Ach-evoked α7-nAChR currents. Interpretation of genistein's effects as due to perturbation of tyrosine-phosphorylation processes is complicated, however, by subsequent findings that genistein is a strong positive allosteric modulator (PAM) of α7-nAChRs. Our study asked if genistein's enhancement of α7-nAChRs currents is entirely attributable to PAM activity, or if non-PAM effects contribute as well. We compared the effects of brief (1 min) vs. extended (24 h) exposure of oocytes expressing α7-nAChRs to genistein (100 μM), both 2 and 5 days following cRNA injections (2.0 ng). On day 2, the Ach-evoked (500 μM) peak currents for control cells, and cells exposed for 1 min, or 24 h, to genistein were (mean ± SEM, nA): 29.32 ± 12.10 (n=24), 130.95 ± 35.42 (n=22), and 374 ± 105.21 (n=8). On day 5, the comparable values were: 108.61 ± 14.85 (n=10), 310.81 ± 56.22 (n=9), and 605.00 ± 128.03 nA (n=11). On day 2, 1 min genistein caused a 4.5 fold-facilitation; 24 h exposure caused a 12.8 fold-facilitation. On day 5, 1 min genistein caused a 2.4 fold-facilitation; 24 h genistein caused a 5.6 fold-facilitation. Thus, genistein-enhancement of α7 currents varied inversely with the degree of functional α7-nAChR expression, being greater for day 2 than 5. Genistein's effect on desensitization of α7-nAChR currents was also separable from facilitation. On day 2, genistein increased peak current without affecting desensitization. On day 5, genistein increased peak current and slowed desensitization. Our results suggest that genistein's enhancement of α7-nAChR currents is not entirely due to PAM effects, but involves other mechanisms too, particularly on day 2.