Citations

Abstract Background: Plant-based diet is recommended by multiple cancer survivorship guidelines and was reported to be associated with better survival among patients with non-metastatic colorectal cancer. However, the association between plant-based diet and survival in metastatic colorectal cancer is unknown. Methods: Using an NCI-sponsored systemic therapy trial conducted from 2005 to 2015 (CALGB/SWOG 80405), we included 1,279 patients who completed validated food frequency questionnaires at the initiation of treatment for metastatic colorectal cancer. To emphasize different impact of healthful plant foods, less healthful plant foods, and animal foods, we used 18 food groups to calculate three plant-based indexes (ranges: 18-90 points): overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI). The primary outcome was overall survival, and the secondary outcome was progression-free survival. We estimated the associations of three indexes (quintiles) with survival using multivariable Cox proportional hazards regression. Results: Of 1,279 patients (median follow-up: 6.1 years), mean (SD) age at diagnosis was 58.8 (11.7) years, 57.4% were men, 85.6% were White, and 1,096 deaths and 1,201 events of progression occurred. The mean (SD) points of three indexes were 51.2 (6.3) for PDI, 51.1 (6.7) for hPDI, and 51.2 (8.1) for uPDI. Compared to the lowest quintile (Q1), the highest quintile (Q5) of PDI was significantly associated with better overall survival (HR: 0.80 [0.65-0.99]) and progression-free survival (HR: 0.80 [0.65-0.98]). Similar findings were observed for hPDI, but uPDI was not significantly associated with worse survival. Conclusions: Our findings suggest that plant-based diet is associated with better survival among patients with metastatic colorectal cancer, and plant-based dietary interventions should be considered for future trials in metastatic colorectal cancer. Table. Adjusted Associations of Plant-Based Diet with Survival in Metastatic Colorectal Cancer Q1 Q2 Q3 Q4 Q5 P for trend Overall Survival PDI 1.00 0.96 (0.80-1.16) 0.93 (0.77-1.14) 0.82 (0.67-0.99) 0.80 (0.65-0.99) 0.01 hPDI 1.00 0.95 (0.78-1.14) 0.94 (0.77-1.15) 0.86 (0.70-1.04) 0.84 (0.68-1.03) 0.07 uPDI 1.00 1.14 (0.95-1.39) 1.07 (0.87-1.31) 1.18 (0.97-1.45) 1.17 (0.95-1.45) 0.15 Progression-free Survival PDI 1.00 0.84 (0.70-1.01) 0.94 (0.78-1.14) 0.93 (0.77-1.12) 0.80 (0.65-0.98) 0.10 hPDI 1.00 0.86 (0.72-1.03) 0.83 (0.69-1.01) 0.80 (0.67-0.97) 0.80 (0.66-0.97) 0.03 uPDI 1.00 1.12 (0.94-1.34) 1.11 (0.91-1.34) 1.10 (0.91-1.34) 1.15 (0.94-1.41) 0.23 Citation Format: En Cheng, Fang-Shu Ou, Chao Ma, Alan P. Venook, Heinz-Josef Lenz, Eileen M. O’Reilly, Peter T. Campbell, Chaoyuan Kuang, Bette J. Caan, Kimmie Ng, Jeffrey A. Meyerhardt. Plant-based diet and survival among patients with metastatic colorectal cancer: Findings from CALGB/SWOG 80405 (Alliance) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2200.

Abstract Background: The genotoxin colibactin causes a tumor single-base substitution (SBS) mutational signature, SBS88. It is unknown whether epidemiologic factors’ association with colorectal cancer risk and survival differs by SBS88. Methods: Within the Genetic Epidemiology of Colorectal Cancer Consortium and Colon Cancer Family Registry, we measured SBS88 in 4,308 microsatellite stable/microsatellite instability low tumors. Associations of epidemiologic factors with colorectal cancer risk by SBS88 were assessed using multinomial regression (N = 4,308 cases, 14,192 controls; cohort-only cases N = 1,911), and with colorectal cancer–specific survival using Cox proportional hazards regression (N = 3,465 cases). Results: 392 (9%) tumors were SBS88 positive. Among all cases, the highest quartile of fruit intake was associated with lower risk of SBS88-positive colorectal cancer than SBS88-negative colorectal cancer [odds ratio (OR) = 0.53, 95% confidence interval (CI) 0.37-0.76; OR = 0.75, 95% CI 0.66–0.85, respectively, Pheterogeneity = 0.047]. Among cohort studies, associations of body mass index (BMI), alcohol, and fruit intake with colorectal cancer risk differed by SBS88. BMI ≥30 kg/m2 was associated with worse colorectal cancer–specific survival among those SBS88-positive [hazard ratio (HR) = 3.40, 95% CI 1.47–7.84], but not among those SBS88-negative (HR = 0.97, 95% CI 0.78–1.21, Pheterogeneity = 0.066). Conclusions: Most epidemiologic factors did not differ by SBS88 for colorectal cancer risk or survival. Higher BMI may be associated with worse colorectal cancer–specific survival among those SBS88-positive; however, validation is needed in samples with whole-genome or whole-exome sequencing available. Impact: This study highlights the importance of identification of tumor phenotypes related to colorectal cancer and understanding potential heterogeneity for risk and survival.

Abstract Purpose: Germline pathogenic variants in CHEK2 confer moderately elevated breast cancer risk (odds ratio, OR ∼ 2.5), qualifying carriers for enhanced breast cancer screening. Besides pathogenic variants, dozens of missense CHEK2 variants of uncertain significance (VUS) have been identified, hampering the clinical utility of germline genetic testing (GGT). Experimental Design: We collected 460 CHEK2 missense VUS identified by the ENIGMA consortium in 15 countries. Their functional characterization was performed using CHEK2-complementation assays quantifying KAP1 phosphorylation and CHK2 autophosphorylation in human RPE1–CHEK2-knockout cells. Concordant results in both functional assays were used to categorize CHEK2 VUS from 12 ENIGMA case–control datasets, including 73,048 female patients with breast cancer and 88,658 ethnicity-matched controls. Results: A total of 430/460 VUS were successfully analyzed, of which 340 (79.1%) were concordant in both functional assays and categorized as functionally impaired (N = 102), functionally intermediate (N = 12), or functionally wild-type (WT)–like (N = 226). We then examined their association with breast cancer risk in the case–control analysis. The OR and 95% CI (confidence intervals) for carriers of functionally impaired, intermediate, and WT-like variants were 2.83 (95% CI, 2.35–3.41), 1.57 (95% CI, 1.41–1.75), and 1.19 (95% CI, 1.08–1.31), respectively. The meta-analysis of population-specific datasets showed similar results. Conclusions: We determined the functional consequences for the majority of CHEK2 missense VUS found in patients with breast cancer (3,660/4,436; 82.5%). Carriers of functionally impaired missense variants accounted for 0.5% of patients with breast cancer and were associated with a moderate risk similar to that of truncating CHEK2 variants. In contrast, 2.2% of all patients with breast cancer carried functionally wild-type/intermediate missense variants with no clinically relevant breast cancer risk in heterozygous carriers.

Abstract Background: The genotoxin colibactin, produced by Escherichia coli containing the pks island, is associated with a tumor single base substitution (SBS) mutational signature SBS88. It is unknown whether lifestyle and environmental factors related to gut dysbiosis impact colorectal cancer (CRC) risk and survival differently by colibactin signature status. Methods: Utilizing the resources of the Genetic Epidemiology of Colorectal cancer Consortium and Colon Cancer Family Registry (GECCO-CCFR), a consortium including both case-control and cohort study designs, SBS88 tumor mutational signature was measured in 4308 CRC cases who were microsatellite stable (MSS) and had at least five somatic single nucleotide variants for signature decomposition. Associations of 13 lifestyle and environmental factors with CRC risk by colibactin signature status were assessed using logistic and multinomial regression; associations with CRC survival were assessed using Cox proportional hazards regression. Results: 392 (9%) of the 4308 MSS tumors were positive for SBS88. Having a BMI ≥30 kg/m2 (versus a BMI 18.5-24.9 kg/m2) was strongly associated with worse CRC-specific survival among those with the SBS88 signature, but not among those with SBS88 negative CRC [further adjusted hazard ratio (HR) = 3.40 95% confidence interval (CI) 1.47, 7.84, and HR = 0.97 95% CI 0.78, 1.21, respectively, P for heterogeneity = 0.066]. Associations of fruit intake with CRC risk may be differential by SBS88 status. In minimally adjusted models, those in the highest quartile of fruit intake (versus the first quartile) had 0.53 (95% CI 0.37, 0.76) times the risk of SBS88 positive CRC, as opposed to 0.75 (95% CI 0.66, 0.85) times the risk of SBS88 negative CRC (P for heterogeneity = 0.047). Among cohort studies specifically, associations between CRC risk and BMI, alcohol, and fruit intake also differed by SBS88 status (P for heterogeneity ranging 0.02-0.05). Conclusions: Higher BMI may be associated with worse CRC-specific survival among those with SBS88 positive tumors. BMI, alcohol, and dietary factors may be differentially associated with CRC risk based on SBS88 status. Citation Format: Claire Elizabeth Thomas, Peter Georgeson, Conghui Qu, Robert S. Steinfelder, Daniel D. Buchanan, Mark A. Jenkins, Andrea Gsur, Jane C. Figueiredo, Polly A. Newcomb, Peter T. Campbell, Christina Newton, Caroline Y. Um, Lisa Boardman, Victor Moreno, Jenny Chang-Claude, Michael Hoffmeister, Marc J. Gunter, Andrew T. Chan, Shuji Ogino, Ellen L. Goode, Brigid Lynch, Yohannes A. Melaku, Steven Gallinger, Sonja I. Berndt, Wen-Yi Huang, Ulrike Peters, Amanda I. Phipps. Lifestyle and environmental factors in relation to colorectal cancer risk and survival by colibactin tumor mutational signature status [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6453.

Abstract Colorectal cancer risk can be impacted by genetic, environmental, and lifestyle factors, including diet and obesity. Gene-environment interactions (G × E) can provide biological insights into the effects of obesity on colorectal cancer risk. Here, we assessed potential genome-wide G × E interactions between body mass index (BMI) and common SNPs for colorectal cancer risk using data from 36,415 colorectal cancer cases and 48,451 controls from three international colorectal cancer consortia (CCFR, CORECT, and GECCO). The G × E tests included the conventional logistic regression using multiplicative terms (one degree of freedom, 1DF test), the two-step EDGE method, and the joint 3DF test, each of which is powerful for detecting G × E interactions under specific conditions. BMI was associated with higher colorectal cancer risk. The two-step approach revealed a statistically significant G×BMI interaction located within the Formin 1/Gremlin 1 (FMN1/GREM1) gene region (rs58349661). This SNP was also identified by the 3DF test, with a suggestive statistical significance in the 1DF test. Among participants with the CC genotype of rs58349661, overweight and obesity categories were associated with higher colorectal cancer risk, whereas null associations were observed across BMI categories in those with the TT genotype. Using data from three large international consortia, this study discovered a locus in the FMN1/GREM1 gene region that interacts with BMI on the association with colorectal cancer risk. Further studies should examine the potential mechanisms through which this locus modifies the etiologic link between obesity and colorectal cancer. Significance: This gene-environment interaction analysis revealed a genetic locus in FMN1/GREM1 that interacts with body mass index in colorectal cancer risk, suggesting potential implications for precision prevention strategies.

AbstractOur objective was to test whether p53 expression status is associated with survival for women diagnosed with the most common ovarian carcinoma histotypes (high‐grade serous carcinoma [HGSC], endometrioid carcinoma [EC], and clear cell carcinoma [CCC]) using a large multi‐institutional cohort from the Ovarian Tumor Tissue Analysis (OTTA) consortium. p53 expression was assessed on 6,678 cases represented on tissue microarrays from 25 participating OTTA study sites using a previously validated immunohistochemical (IHC) assay as a surrogate for the presence and functional effect of TP53 mutations. Three abnormal expression patterns (overexpression, complete absence, and cytoplasmic) and the normal (wild type) pattern were recorded. Survival analyses were performed by histotype. The frequency of abnormal p53 expression was 93.4% (4,630/4,957) in HGSC compared to 11.9% (116/973) in EC and 11.5% (86/748) in CCC. In HGSC, there were no differences in overall survival across the abnormal p53 expression patterns. However, in EC and CCC, abnormal p53 expression was associated with an increased risk of death for women diagnosed with EC in multivariate analysis compared to normal p53 as the reference (hazard ratio [HR] = 2.18, 95% confidence interval [CI] 1.36–3.47, p = 0.0011) and with CCC (HR = 1.57, 95% CI 1.11–2.22, p = 0.012). Abnormal p53 was also associated with shorter overall survival in The International Federation of Gynecology and Obstetrics stage I/II EC and CCC. Our study provides further evidence that functional groups of TP53 mutations assessed by abnormal surrogate p53 IHC patterns are not associated with survival in HGSC. In contrast, we validate that abnormal p53 IHC is a strong independent prognostic marker for EC and demonstrate for the first time an independent prognostic association of abnormal p53 IHC with overall survival in patients with CCC.

INTRODUCTION: Early-onset colorectal cancer diagnosed before the age of 50 years has been increasing. Likely reflecting the pathogenic role of the intestinal microbiome, which gradually changes across the entire colorectal length, the prevalence of certain tumor molecular characteristics gradually changes along colorectal subsites. Understanding how colorectal tumor molecular features differ by age and tumor location is important in personalized patient management. METHODS: Using 14,004 cases with colorectal cancer including 3,089 early-onset cases, we examined microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and KRAS and BRAF mutations in carcinomas of the cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum and compared early-onset cases with later-onset cases. RESULTS: The proportions of MSI-high, CIMP-high, and BRAF -mutated early-onset tumors were lowest in the rectum (8.8%, 3.4%, and 3.5%, respectively) and highest in the ascending colon (46% MSI-high; 15% CIMP-high) or transverse colon (8.6% BRAF -mutated) (all P trend <0.001 across the rectum to ascending colon). Compared with later-onset tumors, early-onset tumors showed a higher prevalence of MSI-high status and a lower prevalence of CIMP-high status and BRAF mutations in most subsites. KRAS mutation prevalence was higher in the cecum compared with that in the other subsites in both early-onset and later-onset tumors ( P < 0.001). Notably, later-onset MSI-high tumors showed a continuous decrease in KRAS mutation prevalence from the rectum (36%) to ascending colon (9%; P trend <0.001), followed by an increase in the cecum (14%), while early-onset MSI-high cancers showed no such trend. DISCUSSION: Our findings support biogeographical and pathogenic heterogeneity of colorectal carcinomas in different colorectal subsites and age groups.

Abstract Background: Tobacco smoking is an established risk factor for colorectal cancer. However, genetically defined population subgroups may have increased susceptibility to smoking-related effects on colorectal cancer. Methods: A genome-wide interaction scan was performed including 33,756 colorectal cancer cases and 44,346 controls from three genetic consortia. Results: Evidence of an interaction was observed between smoking status (ever vs. never smokers) and a locus on 3p12.1 (rs9880919, P = 4.58 × 10−8), with higher associated risk in subjects carrying the GG genotype [OR, 1.25; 95% confidence interval (CI), 1.20–1.30] compared with the other genotypes (OR &lt;1.17 for GA and AA). Among ever smokers, we observed interactions between smoking intensity (increase in 10 cigarettes smoked per day) and two loci on 6p21.33 (rs4151657, P = 1.72 × 10−8) and 8q24.23 (rs7005722, P = 2.88 × 10−8). Subjects carrying the rs4151657 TT genotype showed higher risk (OR, 1.12; 95% CI, 1.09–1.16) compared with the other genotypes (OR &lt;1.06 for TC and CC). Similarly, higher risk was observed among subjects carrying the rs7005722 AA genotype (OR, 1.17; 95% CI, 1.07–1.28) compared with the other genotypes (OR &lt;1.13 for AC and CC). Functional annotation revealed that SNPs in 3p12.1 and 6p21.33 loci were located in regulatory regions, and were associated with expression levels of nearby genes. Genetic models predicting gene expression revealed that smoking parameters were associated with lower colorectal cancer risk with higher expression levels of CADM2 (3p12.1) and ATF6B (6p21.33). Conclusions: Our study identified novel genetic loci that may modulate the risk for colorectal cancer of smoking status and intensity, linked to tumor suppression and immune response. Impact: These findings can guide potential prevention treatments.

Abstract Background: Evidence suggests that, compared to later-onset colorectal cancer (CRC), early-onset CRC (diagnosed before 50 years of age) occur more frequently in rectal location and less frequently in proximal colon location. Studies also indicate heterogeneity of molecular characteristics within early-onset CRCs and between early-onset and later-onset CRCs. Understanding how tumor molecular features and biological aggressiveness of early-onset CRC differ by detailed tumor location is important in personalized patient management. Methods: Using 14,004 CRC cases including 3,089 early-onset cases from The Cancer Genome Atlas and the Genetics and Epidemiology of CRC Consortium (GECCO), we examined microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and KRAS and BRAF mutations in cancers of the cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum. We further conducted CRC-specific survival analyses of detailed tumor location stratified by molecular characteristics using multivariable Cox proportional hazards models. Results: The proportions of MSI-high, CIMP-high, and BRAF-mutated early-onset tumors gradually increased from the rectum (8.8%, 3.4%, and 3.5%, respectively) to the ascending colon (46% MSI-high; 15% CIMP-high) or transverse colon (8.6% BRAF-mutated), followed by declines in the cecum for MSI-high (36%) and BRAF-mutated (4.6%) tumors. Notably, later-onset MSI-high tumors showed a continuous decrease in KRAS mutation prevalence from the rectum (36%) to ascending colon (9%; Ptrend &lt;0.001) followed by an increase in the cecum (14%), while early-onset MSI-high cancer showed no such trend. In survival analyses, there was a trend for better CRC-specific survival from the cecum to sigmoid colon (Ptrend&lt;0.001) (but not to rectum), which did not significantly differ by age of diagnosis (Pinteraction=0.61). Multivariable-adjusted hazard ratios (HRs) for sigmoid vs. cecum were 0.86 (95% CI, 0.64-1.14) for early-onset cases and 0.81 (95% CI, 0.70-0.93) for later-onset cases. Notably, the prognostic association of tumor location differed by MSI status (Pinteraction=0.001). Non-MSI-high tumors exhibited the cecum-to-sigmoid trend for better CRC-specific survival [Ptrend &lt;0.001; multivariable-adjusted HR for the sigmoid colon (vs. cecum), 0.80; 95% CI, 0.70-0.92], whereas MSI-high tumors demonstrated an opposite cecum-to-sigmoid trend for worse survival (Ptrend = 0.020; the corresponding HR, 2.13; 95% CI, 1.15-3.92). Conclusions: Our findings support biogeographical and pathogenic heterogeneity of CRC in different age groups and colorectal subsites. Both detailed colorectal location and tumor molecular features need to be accounted for prognostication of early-onset and later-onset CRCs to advance precision medicine. Citation Format: Tomotaka Ugai, Yin Cao, Koichiro Haruki, Tabitha A. Harrison, Daniel D. Buchanan, Peter T. Campbell, Andrew T. Chan, Steven Gallinger, Marc J. Gunter, Michael Hoffmeister, Mark A. Jenkins, Roger L. Milne, Polly A. Newcomb, Rish K. Pai, Andrew J. Pellatt, Robert E. Schoen, Bethany Van Guelpen, Michael O. Woods, Amanda I. Phipps, Ulrike Peters, Shuji Ogino. Molecular characteristics and prognosis of early-onset colorectal cancer according to detailed anatomical locations: Comparison to later-onset cases [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr A010.

Abstract Background Obesity is an established risk factor for colorectal cancer (CRC), but the evidence for the association is inconsistent across molecular subtypes of the disease. Methods We pooled data on body mass index (BMI), tumor microsatellite instability status, CpG island methylator phenotype status, BRAF and KRAS mutations, and Jass classification types for 11 872 CRC cases and 11 013 controls from 11 observational studies. We used multinomial logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) adjusted for covariables. Results Higher BMI was associated with increased CRC risk (OR per 5 kg/m2 = 1.18, 95% CI = 1.15 to 1.22). The positive association was stronger for men than women but similar across tumor subtypes defined by individual molecular markers. In analyses by Jass type, higher BMI was associated with elevated CRC risk for types 1-4 cases but not for type 5 CRC cases (considered familial-like/Lynch syndrome microsatellite instability-H, CpG island methylator phenotype-low or negative, BRAF-wild type, KRAS-wild type, OR = 1.04, 95% CI = 0.90 to 1.20). This pattern of associations for BMI and Jass types was consistent by sex and design of contributing studies (cohort or case-control). Conclusions In contrast to previous reports with fewer study participants, we found limited evidence of heterogeneity for the association between BMI and CRC risk according to molecular subtype, suggesting that obesity influences nearly all major pathways involved in colorectal carcinogenesis. The null association observed for the Jass type 5 suggests that BMI is not a risk factor for the development of CRC for individuals with Lynch syndrome.