Citations

This selection from the NCCN Guidelines for Rectal Cancer focuses on management of malignant polyps and resectable nonmetastatic rectal cancer because important updates have been made to these guidelines. These recent updates include redrawing the algorithms for stage II and III disease to reflect new data supporting the increasingly prominent role of total neoadjuvant therapy, expanded recommendations for short-course radiation therapy techniques, and new recommendations for a “watch-and-wait” nonoperative management technique for patients with cancer that shows a complete response to neoadjuvant therapy. The complete version of the NCCN Guidelines for Rectal Cancer, available online at NCCN.org , covers additional topics including risk assessment, pathology and staging, management of metastatic disease, posttreatment surveillance, treatment of recurrent disease, and survivorship.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co‐primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. Acquired genomic alterations (Acq-GAs), specifically RAS, BRAF, and EGFR-ectodomain mutations and ERBB2 and MET amplifications, are recognized as major mechanisms of resistance to later-line anti–EGFR-antibody therapy in metastatic colorectal cancer (mCRC). However, data regarding emergence of these Acq-GAs under the selective pressure of first-line anti–EGFR-chemotherapy are lacking. We performed next-generation sequencing (Guardant360) on circulating tumor DNA obtained from paired plasma samples (pretreatment and postprogression) from the CALGB/SWOG-80405 trial, which randomly assigned patients with mCRC between first-line chemotherapy with cetuximab (anti–EGFR-chemotherapy) or bevacizumab (anti–VEGF-chemotherapy). The primary objective was to determine the prevalence of Acq-GAs on anti–EGFR-chemotherapy and compare this to the prevalence with anti–VEGF-chemotherapy on trial and pooled estimates (N = 292) seen with later-line anti–EGFR-antibody therapy as reported in the literature. Among the 61 patients on anti–EGFR-chemotherapy, only four (6.6%) developed ≥ 1 Acq-GAs of interest compared with 10.1% (7) on anti–VEGF-chemotherapy (odds ratio, 0.62; 95% CI, 0.20 to 2.11) and 62.0% on anti–EGFR-antibody therapy in later lines (odds ratio, 0.09; 95% CI, 0.03 to 0.23). Acq-GAs, classically associated with anti–EGFR-antibody resistance in later lines ( RAS, BRAF, and EGFR-ectodomain mutations; ERBB2 and MET amplifications), were rare with up-front use of anti–EGFR-chemotherapy indicating divergent resistance mechanisms. These findings have critical translational relevance to timing and value of circulating tumor DNA–guided anti-EGFR rechallenge in patients with mCRC, especially those treated with anti-EGFR therapy upfront.

AbstractData on diet and survival among people with metastatic colorectal cancer are limited. We examined dietary fat in relation to all‐cause mortality and cancer progression or death among 1149 people in the Cancer and Leukemia Group B (Alliance)/Southwest Oncology Group (SWOG) 80405 trial who completed a food frequency questionnaire at initiation of treatment for advanced or metastatic colorectal cancer. We examined saturated, monounsaturated, total and specific types (n‐3, long‐chain n‐3 and n‐6) of polyunsaturated fat, animal and vegetable fats. We hypothesized higher vegetable fat intake would be associated with lower risk of all‐cause mortality and cancer progression. We used Cox proportional hazards regression to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI). Over median follow‐up of 6.1 years (interquartile range [IQR]: 5.3, 7.2 y), we observed 974 deaths and 1077 events of progression or death. Participants had a median age of 59 y; 41% were female and 86% identified as White. Moderate or higher vegetable fat was associated with lower risk of mortality and cancer progression or death (HRs comparing second, third and fourth to first quartile for all‐cause mortality: 0.74 [0.62, 0.90]; 0.75 [0.61, 0.91]; 0.79 [0.63, 1.00];Ptrend: .12; for cancer progression or death: 0.74 [0.62, 0.89]; 0.78 [0.64, 0.95]; 0.71 [0.57, 0.88];Ptrend: .01). No other fat type was associated with all‐cause mortality and cancer progression or death. Moderate or higher vegetable fat intake may be associated with lower risk of cancer progression or death among people with metastatic colorectal cancer.

Importance National guidelines endorse treatment with neoadjuvant therapy for borderline resectable pancreatic ductal adenocarcinoma (PDAC), but the optimal strategy remains unclear. Objective To compare treatment with neoadjuvant modified FOLFIRINOX (mFOLFIRINOX) with or without hypofractionated radiation therapy with historical data and establish standards for therapy in borderline resectable PDAC. Design, Setting, and Participants This prospective, multicenter, randomized phase 2 clinical trial conducted from February 2017 to January 2019 among member institutions of National Clinical Trials Network cooperative groups used standardized quality control measures and included 126 patients, of whom 70 (55.6%) were registered to arm 1 (systemic therapy; 54 randomized, 16 following closure of arm 2 at interim analysis) and 56 (44.4%) to arm 2 (systemic therapy and sequential hypofractionated radiotherapy; all randomized before closure). Data were analyzed by the Alliance Statistics and Data Management Center during September 2021. Interventions Arm 1: 8 treatment cycles of mFOLFIRINOX (oxaliplatin, 85 mg/m 2 ; irinotecan, 180 mg/m 2 ; leucovorin, 400 mg/m 2 ; and infusional fluorouracil, 2400 mg/m 2 ) over 46 hours, administered every 2 weeks. Arm 2: 7 treatment cycles of mFOLFIRINOX followed by stereotactic body radiotherapy (33-40 Gy in 5 fractions) or hypofractionated image-guided radiotherapy (25 Gy in 5 fractions). Patients without disease progression underwent pancreatectomy, which was followed by 4 cycles of treatment with postoperative FOLFOX6 (oxaliplatin, 85 mg/m 2 ; leucovorin, 400 mg/m 2 ; bolus fluorouracil, 400 mg/m 2 ; and infusional fluorouracil, 2400 mg/m 2 over 46 hours). Main Outcomes and Measures Each treatment arm’s 18-month overall survival (OS) rate was compared with a historical control rate of 50%. A planned interim analysis mandated closure of either arm for which 11 or fewer of the first 30 accrued patients underwent margin-negative (R0) resection. Results Of 126 patients, 62 (49%) were women, and the median (range) age was 64 (37-83) years. Among the first 30 evaluable patients enrolled to each arm, 17 patients in arm 1 (57%) and 10 patients in arm 2 (33%) had undergone R0 resection, leading to closure of arm 2 but continuation to full enrollment in arm 1. The 18-month OS rate of evaluable patients was 66.7% (95% CI, 56.1%-79.4%) in arm 1 and 47.3% (95% CI 35.8%-62.5%) in arm 2. The median OS of evaluable patients in arm 1 and arm 2 was 29.8 (95% CI, 21.1-36.6) months and 17.1 (95% CI, 12.8-24.4) months, respectively. Conclusions and Relevance This randomized clinical trial found that treatment with neoadjuvant mFOLFIRINOX alone was associated with favorable OS in patients with borderline resectable PDAC compared with mFOLFIRINOX treatment plus hypofractionated radiotherapy; thus, mFOLFIRINOX represents a reference regimen in this setting. Trial Registration ClinicalTrials.gov Identifier: NCT02839343

3586 Background: HSP90 mediated chaperoning is a well-conserved biological mechanism for stabilization and activation of kinases. More than 60% of human kinases including VEGFR, CRAF, CSF1R, and FGFR are target of HSP90 (client kinases), whereas EGFR is non-client. CDC37 is a specific co-chaperone determining selectivity of client kinases recognized by HSP90. We hypothesized that gene expression levels of CDC37 have predictive values for anti-angiogenic therapies in mCRC. Methods: The subjects of this study were mCRC patients treated with regorafenib (REGO, Japanese retrospective cohort) and those treated with bevacizumab (BEV) or cetuximab (CET) in combination with first-line chemotherapy (CALGB/SWOG 80405 trial cohort). CDC37 expression levels were measured using RNA isolated from FFPE samples by nCounter gene expression profiling (Nanostring) and HiSeq 2500 (Illumina) in the Japanese and CALGB/SWOG 80405 cohorts, respectively. Overall survival (OS) and progression-free survival (PFS) were compared between patients with high CDC37 expression ( CDC37-H) and those with low expression ( CDC37-L), grouped by median cutoff value in each cohort. Results: In total, 484 patients were included (50 treated with REGO, 227 treated with BEV, and 207 treated with CET). In REGO-treated patients, CDC37-H showed significantly better OS (median 11.3 vs 6.0 months, adjusted hazard ratio [HR] 0.24, 95% confidence interval [CI] 0.11-0.54, p <0.01) and PFS (median 3.5 vs 1.9 months, adjusted HR 0.51, 95% CI 0.28-0.94, p = 0.03) compared to CDC37-L. Similarly, in BEV-treated patients, CDC37-H showed significantly better PFS (median 13.5 vs 9.6 months, adjusted HR 0.59, 95% CI 0.43-0.79, p <0.01) and numerically better OS (median 34.1 vs 29.4 months, adjusted HR 0.81, 95% CI 0.60-1.11, p = 0.20) compared to CDC37-L. However, in CET-treated patients, CDC37-H and CDC37-L patients showed similar OS (median 33.7 vs 26.1 months, adjusted HR 1.00, 95% CI 0.73-1.38, p = 0.98) and PFS (median 11.3 vs 11.0 months, adjusted HR 1.08, 95% CI 0.81-1.45, p = 0.60). Significant interaction was observed between CDC37 expression and treatment in terms of PFS in the CALGB/SWOG 80405 cohort ( p = 0.01). Conclusions: Our results suggest patients with CDC37-dependent ( CDC37-H) tumors may derive more benefit from REGO and BEV both of which target HSP90 client kinases or signaling pathways, but not from CET which target HSP90 non-client kinase. Further validation studies are warranted to develop a novel personalized approach for targeted therapies based on CDC37 expression in mCRC patients. Support: U10CA180821, U10CA180888; Pfizer, Genentech; https://acknowledgments.alliancefound.org. ClinicalTrials.gov Identifier: NCT00265850.

3580 Background: Monoamine oxidases (MAOs), including MAOA and MAOB, are mitochondrial enzymes responsible for catalyzing monoamine oxidation. Increased expression of MAOs were found in several cancer types and high MAOB was associated with worse disease stage and poorer survival in CRC. Positive and negative correlations of MAOB expression with mesenchymal type and epithelial type gene expressions, respectively, have been reported. Hence, we investigated whether MAOB expression is predictive for targeted therapies in mCRC. Methods: 430 mCRC pts treated with either bevacizumab (BEV, n = 224) or cetuximab (CET, n = 206) in combination with first-line chemotherapy within the CALGB/SWOG 80405 trial were included in the analysis. MAOB RNA was isolated from FFPE tumor samples and sequenced on the HiSeq 2500 (Illumina). Overall survival (OS) and progression-free survival (PFS) were compared between groups of pts categorized by tertiles of MAOB expression into high (H), medium (M) and low (L). Hazard ratios (HR) and 95% confidence intervals (CI) were computed from multivariable Cox proportional hazards model, adjusting for age, sex, location, number of metastases, KRAS, MSI status, and treatment with FOLFOX or FOLFIRI. Sensitivity analyses were conducted after stratifying by sex. Logrank P-values describe differences without adjustment for patient characteristics. Results: In CET-treated pts, MAOB-L showed significantly longer OS (median 39.2 vs 30.9 vs 15.9 months, logrank P = 4.7E-05, L vs H (as reference) adjusted HR 0.42, 95% CI [0.27, 0.65]) and PFS (median 13.2 vs 11.8 vs 7.6 months, logrank P = 0.006, L vs H adjusted HR 0.59 [0.40, 0.88]) compared to MAOB-M and MAOB-H, respectively. Similar results were observed when evaluating MAOB expression as a continuous variable. In BEV-treated pts, no significant differences were observed when comparing MAOB expression tertiles; however, pts with lower MAOB expression had significantly better OS, but not PFS, when evaluating MAOB as a continuous variable (Cox LRT P = 0.015, covariate adjusted). In CET-treated pts, the effect of MAOB expression was observed in male but not female pts (OS: median 40.3 vs 30.9 vs 16.1 months by MAOB-L, M, H, respectively, logrank P = 6.8E-05, L vs H adjusted HR 0.33 [0.19, 0.59]; PFS: median 13.8 vs 12.6 vs 7.9 months, logrank P = 0.001, L vs H adjusted HR 0.46 [0.28, 0.79]). A significant interaction was observed between MAOB expression and treatment for OS ( P = 0.010) in males and females combined, but only in males ( P = 0.018) when stratified by sex. Conclusions: Our results suggest that pts with MAOB-L tumors may have greater benefit from CET-based treatment and that targeting MAOB may be a promising strategy to improve patient outcomes. Further validation studies are warranted to develop a novel personalized approach based on MAOB expression in mCRC pts. Clinical trial information: NCT00265850.

3572 Background: Early onset colorectal cancer (eoCRC: disease diagnosed < 50) has been increasing over the past 2 decades. Currently, standard treatment recommendations for eoCRC patients (pts) with metastatic disease does not differ from late-onset CRC (loCRC) pts although outcomes data in eoCRC pts is limited. Methods: Individual patient data on 5,761 treatment-naive metastatic eoCRC pts was pooled from 8 phase II and III randomized EGFRi studies (2000 - 2012) from the ARCAD mCRC database. The distribution of demographics, clinicopathological features, and biomarkers were summarized by age groups. Progression-free survival (PFS) was compared between age groups by stratified Cox models, adjusting for potential confounders. Predictive value of age group was evaluated by testing interaction effect between treatment and age variables based on a subset of trials with concurrent randomizations between regimens with and without EGFRi Results: eoCRC (n=756) were more evenly distributed between gender, had improved performance status (PS), increased likelihood of metastatic resection, and distant lymph node metastasis, but were less likely to have lung metastasis or KRAS mutation compared to loCRC (n=5,005, table 1). eoCRC and loCRC patients had similar distribution of primary tumor sidedness, primary resection, liver and/or peritoneal involvement, number of metastatic sites involved, and BRAF mutations (MT). No difference in PFS for eoCRC versus loCRC pts was noted (7.8 vs. 7.9 months [M], adjusted hazard ratio [HRadj], 1.02, 95% confidence interval [CI], 0.93-1.11). Among pts with KRAS wild type (WT) and left sided primary tumors, univariable analysis of EGFRi demonstrated improved mPFS in loCRC (9.9 vs 8.5M, HR = 0.74, p<0.001), but this benefit was not seen in eoCRC (8.3 vs 8.9 months, HR 1.20, p=0.36). The same pattern was observed upon multivariable analysis (Table). Conclusions: In our pooled analysis, EGFRi + chemotherapy significantly improved PFS in treatment-naïve loCRC patients but not in left sided, KRAS WT, eoCRC patients. Further validation in an independent cohort is warranted. [Table: see text]

3553 Background: Higher levels of plasma 25-hydroxyvitamin D [25(OH)D)] are associated with better outcomes in mCRC, but underlying biologic mechanisms are unknown. Key components of the VitD metabolic pathway include CYP27B1 (encodes 1-α-hydroxylase, converts 25(OH)D to active calcitriol), VitD receptor (VDR), and CYP24A1 (encodes 24-hydroxylase, degrades calcitriol and 25(OH)D into excreted metabolites). Since these factors may affect 25(OH)D levels and potentially mediate VitD activity in mCRC, we examined the relationship between tumoral gene expression (GEx) of CYP27B1, VDR, and CYP24A and pt outcome in a study nested in a randomized phase III trial of first-line chemotherapy plus biologics in mCRC pts, CALGB/SWOG 80405. Methods: We determined GEx of CYP27B1, VDR, and CYP24A1 by RNA sequencing (RNA-Seq) of archival tumor samples using the Illumina TruSeq platform. Primary endpoints were overall (OS) and progression-free survival (PFS). Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for prognostic and molecular characteristics. Results: 562 pts with RNA-Seq data were included. Pts with higher CYP27B1 expression (>median) were less likely to have BRAF wild type (WT) (79% vs 90%) compared to pts with lower expression (p=0.0007). Pts with higher VDR expression (>quartile 1 [Q1]) were younger (median age 59 vs 62 years; p=0.03), more likely to have left-sided (63% vs 46%; p=0.0005) and BRAF WT tumors (89% vs 70%; p<0.0001), and less likely to have RAS WT tumors (70% vs 80%; p=0.02) compared to pts with lower VDR. Pts with higher CYP24A1 expression (>median) were more likely to have left-sided tumors compared to pts with lower expression (63% vs 54%; p=0.03). On multivariable analysis, pts with higher CYP27B1 expression had significantly improved OS (HR 0.84; 95% CI, 0.75-0.93; p=0.002) and PFS (HR 0.89; 95% CI, 0.80-0.99; p=0.04). Higher VDR expression (up to Q1) was associated with significantly improved PFS (HR 0.69; 95% CI, 0.53-0.91; p=0.007) but not OS (HR 0.85; 95% CI, 0.66-1.09; p=0.20). Above Q1, this improvement attenuated. Higher CYP24A1 GEx was not associated with improved OS (HR 0.98; 95% CI, 0.88-1.08; p=0.66) or PFS (HR 0.98; 95% CI, 0.89-1.08; p=0.68). We found no significant interactions between GEx of CYP27B1, VDR, or CYP24A with baseline plasma 25(OH)D levels (p for interaction ≥0.10 for all). Conclusions: Our findings suggest an association between GEx of VitD pathway markers, particularly CYP27B1 and VDR, and survival in pts with mCRC, lending biologic plausibility to a role of VitD in CRC pathogenesis. Future studies are needed to confirm these findings and elucidate underlying mechanisms of action. Clinical trial information: NCT00265850 .

Abstract Purpose: CALGB/SWOG 80405 was a randomized phase III trial in first-line patients with metastatic colorectal cancer treated with bevacizumab, cetuximab, or both, plus chemotherapy. We tested the effect of tumor immune features on overall survival (OS). Experimental Design: Primary tumors (N = 554) were profiled by RNA sequencing. Immune signatures of macrophages, lymphocytes, TGFβ, IFNγ, wound healing, and cytotoxicity were measured. CIBERSORTx scores of naive and memory B cells, plasma cells, CD8+ T cells, resting and activated memory CD4+ T cells, M0 and M2 macrophages, and activated mast cells were measured. Results: Increased M2 macrophage score [HR, 6.30; 95% confidence interval (CI), 3.0–12.15] and TGFβ signature expression (HR, 1.35; 95% CI, 1.05–1.77) were associated with shorter OS. Increased scores of plasma cells (HR, 0.55; 95% CI, 0.38–0.87) and activated memory CD4+ T cells (HR, 0.34; 95% CI, 0.16–0.65) were associated with longer OS. Using optimal cutoffs from these four features, patients were categorized as having either 4, 3, 2, or 0–1 beneficial features associated with longer OS, and the median (95% CI) OS decreased from 42.5 (35.8–47.8) to 31.0 (28.8–34.4), 25.2 (20.6–27.9), and 17.7 (13.5–20.4) months respectively (P = 3.48e–11). Conclusions: New immune features can be further evaluated to improve patient response. They provide the rationale for more effective immunotherapy strategies.

Treatment with the MTOR inhibitor everolimus improves progression-free survival (PFS) in pancreatic neuroendocrine tumors (pNETs), but it is not known if the addition of a VEGF pathway inhibitor to an MTOR inhibitor enhances antitumor activity. We performed a randomized phase II study evaluating everolimus with or without bevacizumab in patients with advanced pNETs. One hundred and fifty patients were randomized to receive everolimus 10 mg daily with or without bevacizumab 10 mg/kg i.v. every 2 weeks. Patients also received standard dose of octreotide in both arms. The primary endpoint was PFS, based on local investigator review. Treatment with the combination of everolimus and bevacizumab resulted in improved progression-free survival compared to everolimus (16.7 months compared to 14.0 months; one-sided stratified log-rank P = 0.1028; hazard ratio (HR) 0.80 (95% CI 0.56–1.13)), meeting the predefined primary endpoint. Confirmed tumor responses were observed in 31% (95% CI 20%, 41%) of patients receiving combination therapy, as compared to only 12% (95% CI 5%, 19%) of patients receiving treatment with everolimus ( P = 0.0053). Median overall survival duration was similar in the everolimus and combination arm (42.5 and 42.1 months, respectively). Treatment-related toxicities were more common in the combination arm. In summary, treatment with everolimus and bevacizumab led to superior PFS and higher response rates compared to everolimus in patients with advanced pNETs. Although the higher rate of treatment-related adverse events may limit the use of this combination, our results support the continued evaluation of VEGF pathway inhibitors in pNETs.