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CRA3507 Background: FOLFOX is standard adjuvant therapy for stage III CC. Adding Cmab to FOLFOX benefits pts with metastatic CC WT KRAS tumors. N0147 assessed the potential benefit of Cmab added to FOLFOX. Methods: 21-56 days following resection and informed consent, KRAS status was centrally determined. Pts with wtKRAS CC were randomized to 12 biweekly cycles of oxaliplatin 85 mg/m2 d1, with leucovorin 400 mg/m2, 5FU 400 mg/m2 bolus IV, then 46-hr IV 5FU 2,400 mg/m2 on d1-2 (mFOLFOX6), without (arm A) or with Cmab (arm D) 250 mg/m2 d1&8, with Cmab at 400 mg/m2, cycle 1, d1. Primary endpoint was 3-yr disease free survival (DFS). Secondary endpoints included overall survival (OS) and toxicity. Planned accrual of 2,070 wtKRAS pts provided 90% power to detect hazard ratio (HR) of 1.33 with 2-sided α=0.05; with interim analyses after 25%, 50%, and 75% of planned events. Results: 1,760 wtKRAS pts (Arm A-858, Arm D-902) were enrolled at the time of closure; median follow-up on 1,624 pts is 15.9 months. Trial closed to accrual when preplanned interim analysis after 50% of planned events demonstrated no benefit to addition of Cmab. 3-yr DFS favored FOLFOX alone (HR 1.18, 95% CI 0.92-1.52; p=0.33). No benefit of Cmab was observed in any subgroups assessed. Any grade ≥ 3 AE, diarrhea, and failure to complete 12 cycles was significantly increased in arm D. Increased toxicity and greater differences in all outcomes were observed in pts aged ≥ 70 ( Table ). Conclusions: In this randomized phase III trial the addition of Cmab to mFOLFOX6 was of no benefit for pts with resected stage III wtKRAS CC. Supported by NIH Grant CA25224, Bristol-Myers Squibb, ImClone, Sanofi-Aventis, and Pfizer. [Table: see text] [Table: see text]

AbstractBackground.Preclinical and epidemiological data suggest that metformin might have antineoplastic properties against colon cancer (CC). However, the effect of metformin use on patient survival in stage III CC after curative resection is unknown. The survival outcomes were comparable regardless of the duration of metformin use.Patients and Methods.Before randomization to FOLFOX (folinic acid, 5-fluorouracil, oxaliplatin) with or without cetuximab, 1,958 patients with stage III CC enrolled in the N0147 study completed a questionnaire with information on diabetes mellitus (DM) and metformin use. Cox models were used to assess the association between metformin use and disease-free survival (DFS), overall survival (OS), and the time to recurrence (TTR), adjusting for clinical and/or pathological factors.Results.Of the 1,958 patients, 1,691 (86%) reported no history of DM, 115 reported DM with metformin use (6%), and 152 reported DM without metformin use (8%). The adjuvant treatment arms were pooled, because metformin use showed homogeneous effects on outcomes across the two arms. Among the patients with DM (n = 267), DFS (adjusted hazard ratio [aHR], 0.90; 95% confidence interval [CI], 0.59–1.35; p = .60), OS (aHR, 0.99; 95% CI, 0.65–1.49; p = .95), and TTR (aHR, 0.87; 95% CI, 0.56–1.35; p = .53) were not different for the metformin users compared with the nonusers after adjusting for tumor and patient factors. The survival outcomes were comparable regardless of the duration of metformin use (<1, 1–5, 6–10, ≥11 years) before randomization (ptrend = .64 for DFS, ptrend = .84 for OS, and ptrend = .87 for TTR). No interaction effects were observed between metformin use and KRAS, BRAF mutation status, tumor site, T/N stage, gender, or age.Conclusions.Patients with stage III CC undergoing adjuvant chemotherapy who used metformin before the diagnosis of CC experienced DFS, OS, and TTR similar to those for non-DM patients and DM patients without metformin use.

Alcohol consumption is associated with a modest increased risk of colon cancer, but its relationship with colon cancer survival has not been elucidated. Using data from a phase III randomized adjuvant trial, we assessed the association of alcohol consumption with colon cancer outcomes. Patients completed a risk factor questionnaire before randomization to FOLFOX or FOLFOX + cetuximab (N = 1984). Information was collected on lifestyle factors, including smoking, physical activity and consumption of different types of alcohol. Cox models assessed the association between alcohol consumption and outcomes of disease‐free survival (DFS), time‐to‐recurrence (TTR) and overall survival (OS), adjusting for age, sex, study arm, body mass, smoking, physical activity and performance status. No statistically significant difference in outcomes between ever and never drinkers were noted [hazard ratio (HR)DFS = 0.86, HRTTR = 0.87, HROS = 0.86, p‐values = 0.11–0.17]. However, when considering alcohol type, ever consumers of red wine (n = 628) had significantly better outcomes than never consumers (HRDFS = 0.80, HRTTR = 0.81, HROS = 0.78, p‐values = 0.01–0.02). Favorable outcomes were confirmed in patients who consumed 1‐30 glasses/month of red wine (n = 601, HR = 0.80–0.83, p‐values = 0.03–0.049); there was a suggestion of more favorable outcomes in patients who consumed >30 glasses/month of red wine (n = 27, HR = 0.33–0.38, p‐values = 0.05–0.06). Beer and liquor consumption were not associated with outcomes. Although alcohol consumption was not associated with colon cancer outcomes overall, mild to moderate red wine consumption was suggestively associated with longer OS, DFS and TTR in stage III colon cancer patients.

Purpose In recent retrospective analyses of early-stage colorectal cancer (CRC), low and high body mass index (BMI) scores were associated with worsened outcomes. Whether BMI is a prognostic or predictive factor in metastatic CRC (mCRC) is unclear. Patients and Methods Individual data from 21,149 patients enrolled onto 25 first-line mCRC trials during 1997 to 2012 were pooled. We assessed both prognostic and predictive effects of BMI on overall survival and progression-free survival, and we accounted for patient and tumor characteristics and therapy type (targeted v nontargeted). Results BMI was prognostic for overall survival (P < .001) and progression-free survival (P < .001), with an L-shaped pattern. That is, risk of progression and/or death was greatest for low BMI; risk decreased as BMI increased to approximately 28 kg/m 2 , and then it plateaued. Relative to obese patients, patients with a BMI of 18.5 kg/m 2 had a 27% increased risk of having a PFS event (95% CI, 20% to 34%) and a 50% increased risk of death (95% CI, 43% to 56%). Low BMI was associated with poorer survival for men than women (interaction P < .001). BMI was not predictive of treatment effect. Conclusion Low BMI is associated with an increased risk of progression and death among the patients enrolled on the mCRC trials, with no increased risk for elevated BMI, in contrast to the adjuvant setting. Possible explanations include negative effects related to cancer cachexia in patients with low BMI, increased drug delivery or selection bias in patients with high BMI, and potential for an interaction between BMI and molecular signaling pathways.

Abstract Purpose: To determine the frequency and prognostic association of molecular markers by anatomic tumor site in patients with stage III colon carcinomas. Experimental Design: In a randomized trial of adjuvant FOLFOX ± cetuximab, BRAFV600E and KRAS (exon 2) mutations and DNA mismatch repair (MMR) proteins were analyzed in tumors (N = 3,018) in relationship to tumor location, including subsite. Cox models were used to assess clinical outcome, including overall survival (OS). Results: KRAS codon 12 mutations were most frequent at the splenic flexure and cecum; codon 13 mutations were evenly distributed. BRAF mutation frequency sharply increased from transverse colon to cecum in parallel with deficient (d) MMR. Nonmutated BRAF and KRAS tumors progressively decreased from sigmoid to transverse (all P &lt; 0.0001). Significantly, poorer OS was found for mutant KRAS in distal [HR, 1.98; 95% confidence interval (CI), 1.49–2.63; P &lt; 0.0001] versus proximal (1.25; 95% CI, 0.97–1.60; P = 0.079) cancers. BRAF status and outcome were not significantly associated with tumor site. Proximal versus distal dMMR tumors had significantly better outcome. An interaction test was significant for tumor site by KRAS (Padjusted = 0.043) and MMR (Padjusted = 0.010) for OS. Significant prognostic differences for biomarkers by tumor site were maintained in the FOLFOX arm. Tumor site was independently prognostic with a stepwise improvement from cecum to sigmoid (OS: Padjusted = 0.001). Conclusions: Mutation in BRAF or KRAS codon 12 was enriched in proximal cancers whereas nonmutated BRAF/KRAS was increased in distal tumors. Significant differences in outcome for KRAS mutations and dMMR were found by tumor site, indicating that their interpretation should occur in the context of tumor location. Clin Cancer Res; 21(23); 5294–304. ©2015 AACR.

Abstract Introduction: Peripheral blood leukocyte (PBL) telomere length is associated with colon cancer (CC) risk, but the relationship of PBL telomere length to survival in CC patients receiving chemotherapy is unknown. Methods: We measured relative telomere length (RTL) by qPCR of PBL DNA from 2,748 cases (53% male, 85% white, median age 58 yrs) in the North American Phase III Intergroup Trial N0147 that compared disease-free survival (DFS) among completely resected Stage III CC treated with mFOLFOX6 +/- cetuximab. Tumor markers were assessed, and 12% were BRAF mutant; 35% Kras mutant, and 12% deficient mismatch repair (dMMR). Linear and non-linear prognostic associations of PBL RTL to the primary endpoint of DFS were assessed by Cox models. Optimal categories of RTL were developed using cumulative martingale residual plots, designated from shortest to longest RTL (Table 1). Results: Never smokers had longer PBL RTL (p = 0.0006) than past or current smokers. Those with diabetes mellitus (DM) had longer PBL RTL than those without DM (p = 0.0165). PBL RTL was not associated with any tumor markers (MMR status; p = 0.7174; BRAF mutant vs wild-type (wt); p =0.4039; Kras mutant vs wt; p= 0.1149). PBL RTL was significantly associated with DFS in a non-linear form (p = 0.0389). Cases in the longer RTL category had more favorable DFS than those with shorter or longest RTL, (Table), which remained after adjusting for age, sex , T/N stage, grade, tumor markers, and treatment (p = 0.0230). We observed no significant interaction (p = 0.1490) between RTL categories and treatment. Conclusion: We observed a non-linear association between RTL and DFS in stage III CC, suggesting that an optimal range telomere length can influence tumor behavior in CC patients. Future studies of telomere maintenance mechanisms may help to explain the association of RTL with improved DFS. RTL is associated with smoking and DM in CC cases but further studies are needed to determine if either tobacco use or DM affect survival from CC by modulating PBL telomere length. Citation Format: Nivedita Basu, Ruth A. Johnson, Qian Shi, Garth D. Nelson, Julie M. Cunningham, Richard M. Goldberg, Frank A. Sinicrope, Daniel J. Sargent, Steven R. Alberts, Gloria M. Petersen, Stephen N. Thibodeau, Halcyon G. Skinner, Kristin Litzelman, Songwon Seo, Russell J. Vanderboom, Ronald E. Gangnon, Corinne D. Engelman, David N. Rider, Lisa A. Boardman. Telomeres and survival in stage III colon cancers: Findings from NCCTG N0147 (Alliance) study. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5102. doi:10.1158/1538-7445.AM2014-5102

PurposeProgression-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.MethodsIndividual 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 R2statistics (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.ResultsForty-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 (R2, 0.45 to 0.69). Analyses limited to trials that tested treatments with biologic agents, nonstrategy trials, or superiority trials did not improve surrogacy.ConclusionIn 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.