Citations

Abstract Background Previous genome-wide association studies (GWAS) have identified 42 loci (P < 5 × 10−8) associated with risk of colorectal cancer (CRC). Expanded consortium efforts facilitating the discovery of additional susceptibility loci may capture unexplained familial risk. Methods We conducted a GWAS in European descent CRC cases and control subjects using a discovery–replication design, followed by examination of novel findings in a multiethnic sample (cumulative n = 163 315). In the discovery stage (36 948 case subjects/30 864 control subjects), we identified genetic variants with a minor allele frequency of 1% or greater associated with risk of CRC using logistic regression followed by a fixed-effects inverse variance weighted meta-analysis. All novel independent variants reaching genome-wide statistical significance (two-sided P < 5 × 10−8) were tested for replication in separate European ancestry samples (12 952 case subjects/48 383 control subjects). Next, we examined the generalizability of discovered variants in East Asians, African Americans, and Hispanics (12 085 case subjects/22 083 control subjects). Finally, we examined the contributions of novel risk variants to familial relative risk and examined the prediction capabilities of a polygenic risk score. All statistical tests were two-sided. Results The discovery GWAS identified 11 variants associated with CRC at P < 5 × 10−8, of which nine (at 4q22.2/5p15.33/5p13.1/6p21.31/6p12.1/10q11.23/12q24.21/16q24.1/20q13.13) independently replicated at a P value of less than .05. Multiethnic follow-up supported the generalizability of discovery findings. These results demonstrated a 14.7% increase in familial relative risk explained by common risk alleles from 10.3% (95% confidence interval [CI] = 7.9% to 13.7%; known variants) to 11.9% (95% CI = 9.2% to 15.5%; known and novel variants). A polygenic risk score identified 4.3% of the population at an odds ratio for developing CRC of at least 2.0. Conclusions This study provides insight into the architecture of common genetic variation contributing to CRC etiology and improves risk prediction for individualized screening.

BACKGROUNDBody weight is associated with colorectal cancer (CRC) risk and survival, but to the authors' knowledge, the impact of long‐term postdiagnostic weight change is unclear. Herein, the authors investigated whether weight change over the 5 years after a diagnosis of CRC is associated with survival.METHODSCRC cases diagnosed from 1997 to 2008 were identified through 4 population‐based cancer registry sites. Participants enrolled within 2 years of diagnosis and reported their height and weight 2 years prior. Follow‐up questionnaires were administered approximately 5 years after diagnosis. Associations between change in weight (in kg) or body mass index (BMI) with overall and CRC‐specific survival were estimated using Cox regression analysis adjusted for age, sex, American Joint Committee on Cancer stage of disease, baseline BMI, nonsteroidal anti‐inflammatory drug use, smoking, time between diagnosis and enrollment, and study site.RESULTSAt the 5‐year postdiagnostic survey, 2049 participants reported higher (53%; median plus 5 kg), unchanged (12%), or lower (35%; median ‐4 kg) weight. Over a median of 5.1 years of subsequent follow‐up (range, 0.3‐9.9 years), 344 participants died (91 of CRC). Long‐term weight loss (per 5 kg) was found to be associated with poorer overall survival (hazard ratio, 1.13; 95% confidence interval, 1.07‐1.21) and CRC‐specific survival (hazard ratio, 1.25; 95% confidence interval, 1.13‐1.39). Significantly lower survival was similarly observed for relative weight loss (>5% vs ≤5% change), BMI reduction (per 1 unit), or BMI category change (overweight to normal vs remaining overweight).CONCLUSIONSWeight loss 5 years after a diagnosis of CRC was found to be significantly associated with decreased long‐term survival, suggesting the importance of avoiding weight loss in survivors of CRC. Future research should attempt to further evaluate this association, accounting for whether this weight change was intentional or represents a marker of declining health. Cancer 2017;123:4701‐4708. © 2017 American Cancer Society.

While elevated blood cholesterol has been associated with an increased risk of colorectal cancer (CRC) in observational studies, causality is uncertain. Here we apply a Mendelian randomisation (MR) analysis to examine the potential causal relationship between lipid traits and CRC risk. We used single nucleotide polymorphisms (SNPs) associated with blood levels of total cholesterol (TC), triglyceride (TG), low‐density lipoprotein (LDL), and high‐density lipoprotein (HDL) as instrumental variables (IV). We calculated MR estimates for each risk factor with CRC using SNP‐CRC associations from 9,254 cases and 18,386 controls. Genetically predicted higher TC was associated with an elevated risk of CRC (odds ratios (OR) per unit SD increase = 1.46, 95% confidence interval [CI]: 1.20–1.79, p = 1.68 × 10−4). The pooled ORs for LDL, HDL, and TG were 1.05 (95% CI: 0.92–1.18, p = 0.49), 0.94 (95% CI: 0.84–1.05, p = 0.27), and 0.98 (95% CI: 0.85–1.12, p = 0.75) respectively. A genetic risk score for 3‐hydoxy‐3‐methylglutaryl‐coenzyme A reductase (HMGCR) to mimic the effects of statin therapy was associated with a reduced CRC risk (OR = 0.69, 95% CI: 0.49–0.99, p = 0.046). This study supports a causal relationship between higher levels of TC with CRC risk, and a further rationale for implementing public health strategies to reduce the prevalence of hyperlipidaemia.

BACKGROUNDAlthough previous studies have noted an increased risk of colorectal cancer (CRC) among moderate to heavy alcohol consumers in comparison with nondrinkers, the relation between alcohol consumption and CRC survival remains unclear.METHODSCases of incident invasive CRC diagnosed between 1997 and 2007 were identified via population‐based cancer registries at 4 study sites in the Colon Cancer Family Registry. Study participants completed a risk‐factor questionnaire on prediagnostic behaviors, including wine, beer, and liquor consumption, at the baseline. Prospective follow‐up for survival was conducted for 4966 CRC cases. Cox regression was used to compare nondrinkers with individuals who consumed, on average, 1 or more servings of alcohol per day in the years preceding their CRC diagnosis with respect to overall and disease‐specific survival. Separate analyses by beverage type, stratified by patient and tumor attributes, were also performed. All models were adjusted for the age at diagnosis, sex, study site, year of diagnosis, smoking history, body mass index, and education.RESULTSPrediagnostic beer and liquor consumption was not associated with CRC survival; however, higher levels of wine consumption were modestly associated with a better prognosis overall (CRC‐specific hazard ratio [HR], 0.70, 95% confidence interval [CI], 0.48‐1.03; overall HR, 0.70; 95% CI, 0.53‐0.94). Similar patterns were noted in stratified analyses.CONCLUSIONSThese findings suggest that prediagnostic wine consumption is modestly associated with more favorable survival after CRC. Cancer 2017;123:1035–43. © 2016 American Cancer Society.

Abstract Background: People with germline mutation in one of the DNA mismatch repair (MMR) genes have increased colorectal cancer risk. For these high-risk people, study findings of the relationship between alcohol consumption and colorectal cancer risk have been inconclusive. Methods: 1,925 MMR gene mutations carriers recruited into the Colon Cancer Family Registry who had completed a questionnaire on lifestyle factors were included. Weighted Cox proportional hazard regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between alcohol consumption and colorectal cancer. Results: Colorectal cancer was diagnosed in 769 carriers (40%) at a mean (SD) age of 42.6 (10.3) years. Compared with abstention, ethanol consumption from any alcoholic beverage up to 14 g/day and &gt;28 g/day was associated with increased colorectal cancer risk (HR, 1.50; 95% CI, 1.09–2.07 and 1.69; 95% CI, 1.07–2.65, respectively; Ptrend = 0.05), and colon cancer risk (HR, 1.78; 95% CI, 1.27–2.49 and 1.94; 95% CI, 1.19–3.18, respectively; Ptrend = 0.02). However, there was no clear evidence for an association with rectal cancer risk. Also, there was no evidence for associations between consumption of individual alcoholic beverage types (beer, wine, spirits) and colorectal, colon, or rectal cancer risk. Conclusions: Our data suggest that alcohol consumption, particularly more than 28 g/day of ethanol (∼2 standard drinks of alcohol in the United States), is associated with increased colorectal cancer risk for MMR gene mutation carriers. Impact: Although these data suggested that alcohol consumption in MMR carriers was associated with increased colorectal cancer risk, there was no evidence of a dose-response, and not all types of alcohol consumption were associated with increased risk. Cancer Epidemiol Biomarkers Prev; 26(3); 366–75. ©2016 AACR.

Abstract Background: Although high-risk mutations in identified major susceptibility genes (DNA mismatch repair genes and MUTYH) account for some familial aggregation of colorectal cancer, their population prevalence and the causes of the remaining familial aggregation are not known. Methods: We studied the families of 5,744 colorectal cancer cases (probands) recruited from population cancer registries in the United States, Canada, and Australia and screened probands for mutations in mismatch repair genes and MUTYH. We conducted modified segregation analyses using the cancer history of first-degree relatives, conditional on the proband's age at diagnosis. We estimated the prevalence of mutations in the identified genes, the prevalence of HR for unidentified major gene mutations, and the variance of the residual polygenic component. Results: We estimated that 1 in 279 of the population carry mutations in mismatch repair genes (MLH1 = 1 in 1,946, MSH2 = 1 in 2,841, MSH6 = 1 in 758, PMS2 = 1 in 714), 1 in 45 carry mutations in MUTYH, and 1 in 504 carry mutations associated with an average 31-fold increased risk of colorectal cancer in unidentified major genes. The estimated polygenic variance was reduced by 30% to 50% after allowing for unidentified major genes and decreased from 3.3 for age &lt;40 years to 0.5 for age ≥70 years (equivalent to sibling relative risks of 5.1 to 1.3, respectively). Conclusions: Unidentified major genes might explain one third to one half of the missing heritability of colorectal cancer. Impact: Our findings could aid gene discovery and development of better colorectal cancer risk prediction models. Cancer Epidemiol Biomarkers Prev; 26(3); 404–12. ©2016 AACR.

MicroRNAs (miRNAs) regulate up to one‐third of all protein‐coding genes including genes relevant to cancer. Variants within miRNAs have been reported to be associated with prognosis, survival, response to chemotherapy across cancer types, in vitro parameters of cell growth, and altered risks for development of cancer. Five miRNA variants have been reported to be associated with risk for development of colorectal cancer (CRC). In this study, we evaluated germline genetic variation in 1,123 miRNAs in 899 individuals with CRCs categorized by clinical subtypes and in 204 controls. The role of common miRNA variation in CRC was investigated using single variant and miRNA‐level association tests. Twenty‐nine miRNAs and 30 variants exhibited some marginal association with CRC in at least one subtype of CRC. Previously reported associations were not confirmed (n = 4) or could not be evaluated (n = 1). The variants noted for the CRCs with deficient mismatch repair showed little overlap with the variants noted for CRCs with proficient mismatch repair, consistent with our evolving understanding of the distinct biology underlying these two groups. © 2016 The Authors Genes, Chromosomes & Cancer Published by Wiley Periodicals, Inc.

Abstract Previous studies have shown an increased risk of colorectal cancer (CRC) among moderate to heavy alcohol consumers relative to non-drinkers; however, the relationship between alcohol and CRC survival remains unclear. Using data from the international Colon Cancer Family Registry (CCFR), we assessed the association between pre-diagnostic alcohol intake and survival outcomes after CRC diagnosis, overall and stratified by patient and tumor attributes. CRC cases were identified via population-based cancer registries at four CCFR study sites, with diagnoses of incident, invasive CRC from 1997 to 2006. Study participants completed a risk factor questionnaire at enrollment which included information on several pre-diagnostic behaviors, including consumption of wine, beer, and liquor. Prospective follow-up for survival outcomes was conducted for 4858 CRC cases with complete data on alcohol consumption. Using Cox proportional hazards regression models with delayed entry to account for the time between diagnosis and study enrollment, we compared non-drinkers (i.e., alcohol intake &lt;1 drink per week) to individuals who consumed, on average, &lt;1 serving of alcohol per day (but ≥1 per week), and those who consumed ≥1 serving per day in the years preceding CRC diagnosis. Separate analyses were carried out for overall and disease-specific survival. All models were adjusted for age at diagnosis, sex, study site, year of diagnosis, smoking history, CRC screening history, and body mass index. Over a mean follow-up of 7.5 years, 1872 (39%) study participants died, 1110 (59%) of whom died from CRC. Pre-diagnostic beer and liquor consumption were not associated with CRC survival; however, consumption of ≥1 serving of wine per day was modestly associated with more favorable overall [hazard ratio (HR) = 0.80, 95% confidence interval (CI): 0.63-1.00] and disease-specific survival (HR = 0.83, 95% CI: 0.62-1.12). In stratified analyses, having consumed ≥1 serving of wine per day was slightly, but not statistically significantly, more strongly associated with overall survival among men than among women (HR = 0.71 vs. 0.91, respectively, p-heterogeneity = 0.12) and among those aged ≤50 than those aged &gt;50 years (HR = 0.66 vs. 0.84, p-heterogeneity = 0.35). Similar patterns were noted with respect to disease-specific survival. There were no differences in the relationships between wine consumption and survival outcomes stratified by tumor site, microsatellite instability, BRAF-mutation, or CpG island methylator phenotype status. These results suggest that wine consumption prior to CRC diagnosis is modestly associated with more favorable survival after CRC diagnosis. This modest inverse association does not appear to be limited to specific colorectal tumor subtypes and extends beyond overall survival to disease-specific outcomes. Citation Format: Amanda I. Phipps, Jamaica Robinson, Peter T. Campbell, Aung Ko Win, Jane Figueiredo, Noralane M. Lindor, Polly A. Newcomb. Prediagnostic alcohol consumption and colorectal cancer survival: the Colon Cancer Family Registry. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3425.