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PURPOSE: Earlier detection of cancer recurrence using circulating tumor DNA (ctDNA) to detect molecular residual disease (MRD) has the potential to dramatically affect cancer management. We review evidence supporting the use of ctDNA as a biomarker for detection of MRD and highlight the potential impact that ctDNA testing could have on the conduct of clinical trials. METHODS: We searched the literature using MEDLINE (via PubMed) for articles from January 1, 2000, focusing on studies that assessed ctDNA as a predictor of cancer recurrence. Broadly focused searches on ctDNA and cancer were also performed to provide additional background information. www.clinialtrials.gov was searched to identify trials that incorporate ctDNA testing. RESULTS: Numerous studies across different cancer types indicate that ctDNA-based MRD detection predicts recurrence with high sensitivity and specificity, and with lead times that precede standard imaging by up to 12 months. Recently, ctDNA testing has started being used to enroll MRD-positive patients at high risk of recurrence into trials, promising gains in statistical power that allow clinical utility to be demonstrated with smaller cohorts. Trials where ctDNA testing based-MRD detection is used to stratify patients into low or high-risk categories for treatment assignment are also ongoing. In addition, there is increasing evidence supporting the use of ctDNA dynamics or clearance as a surrogate end point, which could significantly reduce trial duration. CONCLUSION: ctDNA-based trial enrichment across many cancers seems likely to become increasingly common for cost- and time-reduction benefits. Trial efficiency could also benefit from using ctDNA as a surrogate end point, leading to accelerated approval of new therapeutics. A clear demonstration of efficacy from trials that use ctDNA-based MRD detection to assign treatment could transform clinical practice. [ABSTRACT FROM AUTHOR]

PURPOSE: Promising single-agent activity from sotorasib and adagrasib in KRAS G12C-mutant tumors has provided clinical evidence of effective KRAS signaling inhibition. However, comprehensive analysis of KRAS -variant prevalence, genomic alterations, and the relationship between KRAS and immuno-oncology biomarkers is lacking. MATERIALS AND METHODS: Retrospective analysis of deidentified records from 79,004 patients with various cancers who underwent next-generation sequencing was performed. Fisher's exact test evaluated the association between cancer subtypes and KRAS variants. Logistic regression assessed KRAS G12C comutations with other oncogenes and the association between KRAS variants and immuno-oncology biomarkers. RESULTS: Of the 79,004 samples assessed, 13,758 (17.4%) harbored KRAS mutations, with 1,632 (11.9%) harboring KRAS G12C and 12,126 (88.1%) harboring other KRAS variants (KRAS non-G12C). Compared with KRAS non-G12C across all tumor subtypes, KRAS G12C was more prevalent in females (56% v 51%, false discovery rate-adjusted P value [FDR- P ] =.0006), current or prior smokers (85% v 56%, FDR- P <.0001), and patients age > 60 years (73% v 63%, FDR- P ≤.0001). The most frequent KRAS variants across all subtypes were G12D (29.5%), G12V (23.0%), G12C (11.9%), G13D (6.5%), and G12R (6.2%). KRAS G12C was most prevalent in patients with non–small-cell lung cancer (9%), appendiceal (3.9%), colorectal (3.2%), tumor of unknown origin (1.6%), small bowel (1.43%), and pancreatic (1.3%) cancers. Compared with KRAS non-G12C-mutated, KRAS G12C-mutated tumors were significantly associated with tumor mutational burden-high status (17.9% v 8.4%, odds ratio [OR] = 2.38; FDR- P <.0001). KRAS G12C-mutated tumors exhibited a distinct comutation profile from KRAS non-G12C-mutated tumors, including higher comutations of STK11 (20.59% v 5.95%, OR = 4.10; FDR- P <.01) and KEAP1 (15.38% v 4.61%, OR = 3.76; FDR- P <.01). CONCLUSION: This study presents the first large-scale, pan-cancer genomic characterization of KRAS G12C. The KRAS G12C mutation was more prevalent in females and older patients and appeared to be associated with smoking status. KRAS G12C tumors exhibited a distinct comutation profile and were associated with tumor mutational burden-high status. Landscape of KRASG12C and associated genomic alterations in KRAS-mutated cancers. [ABSTRACT FROM AUTHOR]

The management of locally advanced rectal cancer has grown in both complexity and quality since the first proctectomy. What once was a malignancy with a fairly consistent treatment algorithm for decades, a recent paradigm shift in the care of these patients has led to a more personalized, multidisciplinary approach with variations in timing, sequence, duration, and potential exclusion of multimodality therapies. This review summarizes the most important evidence behind these developing overarching concepts to provide a context for this paradigm shift. [ABSTRACT FROM AUTHOR]

PURPOSE: Gene fusions are established oncogenic drivers and emerging therapeutic targets in advanced colorectal cancer. This study aimed to detail the frequencies and clinicopathological features of gene fusions in colorectal cancer using a circulating tumor DNA assay. METHODS: Circulating tumor DNA samples in patients with advanced colorectal cancer were analyzed at 4,581 unique time points using a validated plasma-based multigene assay that includes assessment of fusions in FGFR2 , FGFR3 , RET , ALK , NTRK1 , and ROS1. Associations between fusions and clinicopathological features were measured using Fisher's exact test. Relative frequencies of genomic alterations were compared between fusion-present and fusion-absent cases using an unpaired t test. RESULTS: Forty-four unique fusions were identified in 40 (1.1%) of the 3,808 patients with circulating tumor DNA detected: RET (n = 6; 36% of all fusions detected), FGFR3 (n = 2; 27%), ALK (n = 10, 23%), NTRK1 (n = 3; 7%), ROS1 (n = 2; 5%), and FGFR2 (n = 1; 2%). Relative to nonfusion variants detected, fusions were more likely to be subclonal (odds ratio, 8.2; 95% CI, 2.94 to 23.00; P <.001). Mutations associated with a previously reported anti–epidermal growth factor receptor (anti-EGFR) therapy resistance signature (subclonal RAS and EGFR mutations) were found with fusions in FGFR3 (10 of 12 patients), RET (nine of 16 patients), and ALK (seven of 10 patients). For the 27 patients with available clinical histories, 21 (78%) had EGFR monoclonal antibody treatment before fusion detection. CONCLUSION: Diverse and potentially actionable fusions can be detected using a circulating tumor DNA assay in patients with advanced colorectal cancer. Distribution of coexisting subclonal mutations in EGFR , KRAS , and NRAS in a subset of the patients with fusion-present colorectal cancer suggests that these fusions may arise as a novel mechanism of resistance to anti-EGFR therapies in patients with metastatic colorectal cancer. [ABSTRACT FROM AUTHOR]

In the past decade, significant advances have been made in the treatment of advanced colorectal cancer. Multiple cytotoxic agents and targeted therapies have been approved for management of metastatic colorectal cancer, leading to improvement of median overall survival in clinical trials to more than 30 months. Of note, before the introduction of biologics into treatment algorithms for metastatic colorectal cancer, median survival in phase III trials never exceeded 24 months. In 2016, the most common treatment approach in first line is a combination of chemotherapy with a biologic agent. The choice of therapy is influenced by patient factors (eg, age, comorbidities), tumor characteristics (eg, overall tumor burden, pattern of metastatic spread, mutation signature), potential adverse effects of therapy, and goals of treatment. The choice between irinotecan- or oxaliplatin-based cytotoxic chemotherapy regimen is primarily based on differential toxicity profile because they have similar efficacy. Currently, three biologic agents--bevacizumab, cetuximab, and panitumumab--are approved for first-line treatment of metastatic colorectal cancer. For patients with mutant RAS and likely mutant BRAF V600E tumors, bevacizumab is the only biologic agent that can be used in conjunction with cytotoxic chemotherapy. The choice of anti-epidermal growth factor antibody or anti-vascular endothelial growth factor antibody in RAS wild-type tumors is based on the specificclinical scenario. Recently, some clinical and molecular biomarkers have emerged that may help in decision making. In this review, we discuss the role of biologics in the management of first-line treatment of metastatic colorectal cancer. [ABSTRACT FROM AUTHOR]

Abstract Purpose: Patient-reported outcomes (PROs) such as pain, fatigue, and quality of life (QOL) are important for morbidity and mortality in patients with cancer. Systematic approaches to collect and incorporate PROs into clinical practice are still evolving. We set out to determine the impact of PRO assessment on routine clinical practice. Methods: Beginning in July 2010, the symptom assessment questionnaire (SAQ) was administered to every patient in a solid tumor oncology practice at an academic center. The SAQ measures pain, fatigue, and QOL, each on a scale of 0 to 10 points. Results were available to providers before each visit in the electronic medical record. Eighteen months after the SAQ was implemented, an online survey was sent to 83 oncology care providers regarding the use of the SAQ and how it affected their clinical practice, including discussion with patients, duration of visits, and work burden. Results: A total of 53% of care providers completed the online survey, producing 44 evaluable surveys. Of these, 86% of care providers reported using information from the SAQ; 90% of care providers indicated the SAQ did not change the length of clinic visits or contribute to increased work burden. A majority of care providers felt that the SAQ had helped or enhanced their practice. Providers endorsed the SAQ for facilitating communication with their patients. Conclusion: This study indicates that simple single-item measures of pain, fatigue, and QOL can be incorporated into oncology clinical practice with positive implications for both patients and physicians without increasing duration of visits or work burden. [ABSTRACT FROM AUTHOR]

Purpose: BEACON CRC evaluated encorafenib plus cetuximab with or without binimetinib versus investigators' choice of irinotecan or FOLFIRI plus cetuximab in patients with BRAF V600E-mutant metastatic colorectal cancer (mCRC), after progression on 1-2 prior regimens. In the previously reported primary analysis, encorafenib, binimetinib plus cetuximab (ENCO/BINI/CETUX; triplet) and encorafenib plus cetuximab (ENCO/CETUX; doublet) regimens improved overall survival (OS) and objective response rate (ORR; by blinded central review) versus standard of care. The purpose of this analysis was to report updated efficacy and safety data., Methods: In this open-label, phase III trial, 665 patients with BRAF V600E-mutant mCRC were randomly assigned 1:1:1 to receive triplet, doublet, or control. Primary end points were OS and independently reviewed ORR comparing triplet to control. OS for doublet versus control was a key secondary end point. Updated analyses include 6 months of additional follow-up and ORR for all randomized patients., Results: Patients received triplet (n = 224), doublet (n = 220), or control (n = 221). Median OS was 9.3 months (95% CI, 8.2 to 10.8) for triplet and 5.9 months (95% CI, 5.1 to 7.1) for control (hazard ratio [HR], 0.60 [95% CI, 0.47 to 0.75]). Median OS for doublet was 9.3 months (95% CI, 8.0 to 11.3) (HR v control, 0.61 [95% CI, 0.48 to 0.77]). Confirmed ORR was 26.8% (95% CI, 21.1% to 33.1%) for triplet, 19.5% (95% CI, 14.5% to 25.4%) for doublet, and 1.8% (95% CI, 0.5% to 4.6%) for control. Adverse events were consistent with the prior primary analysis, with grade ≥ 3 adverse events in 65.8%, 57.4%, and 64.2% for triplet, doublet, and control, respectively., Conclusion: In the BEACON CRC study, encorafenib plus cetuximab improved OS, ORR, and progression-free survival in previously treated patients in the metastatic setting compared with standard chemotherapy. Based on the primary and updated analyses, encorafenib plus cetuximab is a new standard care regimen for previously treated patients with BRAF V600E mCRC.

Purpose Molecular diagnostic testing has become an integral part of the evaluation of patients with metastatic colorectal cancer (CRC). Expanded mutational testing, such as next-generation sequencing (NGS), often identifies mutations with unclear clinical or prognostic implications. One such example is BRAF mutations that occur outside of codon 600 ( non-V600 BRAF mutations). Methods We conducted this multicenter, retrospective cohort study to characterize the clinical, pathologic, and survival implications of non-V600 BRAF mutations in metastatic CRC. We pooled patients in whom non-V600 BRAF mutations were identified from NGS databases at three large molecular genetics reference laboratories. Results A total of 9,643 patients with metastatic CRC underwent NGS testing. We identified 208 patients with non-V600 BRAF mutations, which occurred in 2.2% of all patients tested and accounted for 22% of all BRAF mutations identified. Cancers with non-V600 BRAF mutations, compared with cancers with V600E BRAF ( V600E BRAF) mutations, were found in patients who were significantly younger (58 v 68 years, respectively), fewer female patients (46% v 65%, respectively), and patients who had fewer high-grade tumors (13% v 64%, respectively) or right-sided primary tumors (36% v 81%, respectively). Median overall survival was significantly longer in patients with non-V600 BRAF-mutant metastatic CRC compared with those with both V600E BRAF-mutant and wild-type BRAF metastatic CRC (60.7 v 11.4 v 43.0 months, respectively; P < .001). In multivariable analysis, non-V600 BRAF mutation was independently associated with improved overall survival (hazard ratio, 0.18; P < .001). Conclusion Non-V600 BRAF mutations occur in approximately 2.2% of patients with metastatic CRC and define a clinically distinct subtype of CRC with an excellent prognosis.

Purpose: Progression-free survival (PFS) has previously been established as a surrogate for overall survival (OS) for first-line metastatic colorectal cancer (mCRC). Because mCRC treatment has advanced in the last decade with extended OS, this surrogacy requires re-examination., Methods: Individual patient data from 16,762 patients were available from 22 first-line mCRC studies conducted from 1997 to 2006; 12 of those studies tested antiangiogenic and/or anti-epidermal growth factor receptor agents. The relationship between PFS (first event of progression or death) and OS was evaluated by using R(2) statistics (the closer the value is to 1, the stronger the correlation) from weighted least squares regression of trial-specific hazard ratios estimated by using Cox and Copula models., Results: Forty-four percent of patients received a regimen that included biologic agents. Median first-line PFS was 8.3 months, and median OS was 18.2 months. The correlation between PFS and OS was modest (R(2), 0.45 to 0.69). Analyses limited to trials that tested treatments with biologic agents, nonstrategy trials, or superiority trials did not improve surrogacy., Conclusion: In modern mCRC trials, in which survival after the first progression exceeds time to first progression, a positive but modest correlation was observed between OS and PFS at both the patient and trial levels. This finding demonstrates the substantial variability in OS introduced by the number of lines of therapy and types of effective subsequent treatments and the associated challenge to the use of OS as an end point to assess the benefit attributable to a single line of therapy. PFS remains an appropriate primary end point for first-line mCRC trials to detect the direct treatment effect of new agents., (© 2014 by American Society of Clinical Oncology.)

Purpose: With improved patient care, better diagnosis, and more treatment options after tumor recurrence, outcomes after fluorouracil (FU) -based treatment are expected to have improved over time in early-stage colon cancer. Data from 18,449 patients enrolled onto 21 phase III trials conducted from 1978 to 2002 were evaluated for potential differences in time to recurrence (TTR), time from recurrence to death (TRD), and overall survival (OS) with regard to FU-based adjuvant regimens., Methods: Trials were predefined as old versus newer era using initial accrual before or after 1995. Outcomes were compared between patients enrolled onto old- or newer-era trials, stratified by stage., Results: Within the first 3 years, recurrence rates were lower in newer- versus old-era trials for patients with stage II disease, with no differences among those with stage III disease. Both TRD and OS were significantly longer in newer-era trials overall and within each stage. The lymph node (LN) ratio (ie, number of positive nodes divided by total nodes harvested) in those with stage III disease declined over time. TTR improved slightly, with larger number of LNs examined in both stages., Conclusion: Improved TRD in newer trials supports the premise that more aggressive intervention (oxaliplatin- and irinotecan-based chemotherapy and/or surgery for recurrent disease) improves OS for patients previously treated in the adjuvant setting. Lower recurrence rates with identical treatments in those with stage II disease enrolled onto newer-era trials reflect stage migration over time, calling into question historical data related to the benefit of FU-based adjuvant therapy in such patients.

Purpose: Cumulative sensory neurotoxicity (sNT) is the dose-limiting toxicity of oxaliplatin, which commonly leads to early discontinuation of oxaliplatin-based therapy in the palliative and adjuvant settings. In a nonrandomized, retrospective study, intravenous (IV) calcium/magnesium (Ca/Mg) was associated with reduced oxaliplatin-induced sNT., Methods: Patients with colon cancer undergoing adjuvant therapy with infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX) were randomly assigned to Ca/Mg (1g calcium gluconate plus 1g magnesium sulfate pre- and post-oxaliplatin) or placebo, in a double-blinded manner. The primary end point was the percentage of patients with grade 2 or greater sNT at any time during or after oxaliplatin-based therapy by National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE; version 3) criteria. An oxaliplatin-specific sNT scale and patient questionnaires were also used to assess sNT. After 104 of 300 planned patients were enrolled, the study was closed. This was due to preliminary reports from another trial that suggested that Ca/Mg decreased treatment efficacy; these data were subsequently found to be incorrect., Results: Overall, 102 patients were available for analysis. Ca/Mg decreased the incidence of chronic, cumulative, grade 2 or greater sNT, as measured by NCI CTCAE (P = .038) and also by the oxaliplatin-specific sNT scale (P = .018). In addition, acute muscle spasms associated with oxaliplatin were significantly reduced (P = .01) No effect on acute, cold-induced sNT was found. No substantial differences in adverse effects were noted between Ca/Mg and placebo., Conclusion: Despite early termination and decreased statistical power, this study supports IV Ca/Mg as an effective neuroprotectant against oxaliplatin-induced cumulative sNT in adjuvant colon cancer.