Cross-Cancer Genome-Wide Analysis of Lung, Ovary, Breast, Prostate, and Colorectal Cancer Reveals Novel Pleiotropic Associations

Identifying genetic variants with pleiotropic associations can uncover common pathways influencing multiple cancers. We took a two-stage approach to conduct genome-wide association studies for lung, ovary, breast, prostate, and colorectal cancer from the GAME-ON/GECCO Network (61,851 cases, 61,820 controls) to identify pleiotropic loci. Findings were replicated in independent association studies (55,789 cases, 330,490 controls). We identified a novel pleiotropic association at 1q22 involving breast and lung squamous cell carcinoma, with eQTL analysis showing an association with ADAM15/THBS3 gene expression in lung. We also identified a known breast cancer locus CASP8/ALS2CR12 associated with prostate cancer, a known cancer locus at CDKN2B-AS1 with different variants associated with lung adenocarcinoma and prostate cancer, and confirmed the associations of a breast BRCA2 locus with lung and serous ovarian cancer. This is the largest study to date examining pleiotropy across multiple cancer-associated loci, identifying common mechanisms of cancer development and progression. Cancer Res; 76(17); 5103-14. ©2016 AACR.

Ovarian Cancer Risk Factors by Histologic Subtype: An Analysis From the Ovarian Cancer Cohort Consortium

PURPOSE

An understanding of the etiologic heterogeneity of ovarian cancer is important for improving prevention, early detection, and therapeutic approaches. We evaluated 14 hormonal, reproductive, and lifestyle factors by histologic subtype in the Ovarian Cancer Cohort Consortium (OC3).

PATIENTS AND METHODS

Among 1.3 million women from 21 studies, 5,584 invasive epithelial ovarian cancers were identified (3,378 serous, 606 endometrioid, 331 mucinous, 269 clear cell, 1,000 other). By using competing-risks Cox proportional hazards regression stratified by study and birth year and adjusted for age, parity, and oral contraceptive use, we assessed associations for all invasive cancers by histology. Heterogeneity was evaluated by likelihood ratio test.

RESULTS

Most risk factors exhibited significant heterogeneity by histology. Higher parity was most strongly associated with endometrioid (relative risk [RR] per birth, 0.78; 95% CI, 0.74 to 0.83) and clear cell (RR, 0.68; 95% CI, 0.61 to 0.76) carcinomas (P value for heterogeneity [P-het] < .001). Similarly, age at menopause, endometriosis, and tubal ligation were only associated with endometrioid and clear cell tumors (P-het ≤ .01). Family history of breast cancer (P-het = .008) had modest heterogeneity. Smoking was associated with an increased risk of mucinous (RR per 20 pack-years, 1.26; 95% CI, 1.08 to 1.46) but a decreased risk of clear cell (RR, 0.72; 95% CI, 0.55 to 0.94) tumors (P-het = .004). Unsupervised clustering by risk factors separated endometrioid, clear cell, and low-grade serous carcinomas from high-grade serous and mucinous carcinomas.

CONCLUSION

The heterogeneous associations of risk factors with ovarian cancer subtypes emphasize the importance of conducting etiologic studies by ovarian cancer subtypes. Most established risk factors were more strongly associated with nonserous carcinomas, which demonstrate challenges for risk prediction of serous cancers, the most fatal subtype.

Common variants in the obesity-associated genes FTO and MC4R are not associated with risk of colorectal cancer

BACKGROUND

Obesity is a convincing risk factor for colorectal cancer. Genetic variants in or near FTO and MC4R are consistently associated with body mass index and other body size measures, but whether they are also associated with colorectal cancer risk is unclear.

METHODS

In the discovery stage, we tested associations of 677 FTO and 323 MC4R single nucleotide polymorphisms (SNPs) 100kb upstream and 300kb downstream from each respective locus with risk of colorectal cancer in data from the Colon Cancer Family Registry (CCFR: 1960 cases; 1777 controls). Next, all SNPs that were nominally statistically significant (p<0.05) in the discovery stage were included in replication analyses in data from the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO: 9716 cases; 9844 controls).

RESULTS

In the discovery stage, 43 FTO variants and 18 MC4R variants were associated with colorectal cancer risk (p<0.05). No SNPs remained statistically significant in the replication analysis after accounting for multiple comparisons.

CONCLUSION

We found no evidence that individual variants in or near the obesity-related genes FTO and MC4R are associated with risk of colorectal cancer.

Abstract 2587: Comprehensive colorectal cancer risk prediction to inform personalized screening and intervention

Colorectal cancer (CRC) is the second leading cause of cancer deaths in the United States, despite the fact that it is one of the most preventable and treatable cancers when detected early via screening. The current screening guidelines for CRC are based on age, family history of CRC, and previous screening results. However, multiple environmental and lifestyle risk factors have been established or suspected for CRC, as have many common genetic susceptibility loci. It is critical to utilize this information to better stratify individuals into low- and high-risk groups for optimized and personalized screening and intervention recommendations.

Using data from two large consortia (8421 CRC cases and 9767 controls): the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO) and the Colorectal Transdisciplinary study (CORECT), we developed risk prediction models for men and women based on family history, environmental and lifestyle risk factors, and known CRC susceptibility loci identified through genome-wide association studies. We constructed an environmental risk score (E-score) as a weighted sum of 19 established or potential environmental and lifestyle risk factors for CRC with weights obtained from a multivariate logistic regression analysis. Compared to the model that includes only family history, the E-score significantly improves the discriminatory accuracy for both men (AUC = 0.62 vs. 0.53, p-value &lt; 1e-5) and women (AUC = 0.60 vs. 0.52, p-value &lt; 1e-5). Similarly, we also constructed a genetic risk score (G-score) using 50 common variants associated with CRC risk, and the G-score also significantly improves the discriminatory accuracy for both men (AUC = 0.60 vs. 0.53, p-value &lt; 1e-5) and women (AUC = 0.59 vs. 0.52, p-value &lt; 1e-5) over the family history-only model. Compared to the model with family history and E-score, the inclusion of the G-score in the model further improves the discriminatory accuracy for both men (AUC = 0.65 vs. 0.62, p-value = 0.0152) and women (AUC = 0.63 vs. 0.60, p-value = 0.0005).

Our risk prediction models are the first to incorporate both comprehensive environmental and lifestyle risk factors, and known CRC common genetic variants. The E- and G-scores are independent risk predictors for CRC, and models that incorporate both scores improve the discriminatory accuracy significantly compared to family history-only models. Using risk-factor distributions available from nationally representative data (e.g., NHANES), we will provide absolute-risk estimates of CRC using both the E- and G-scores. We expect our comprehensive models incorporating both environmental and genetic risk factors to provide more accurate estimation of CRC, which will be useful for recommending individually tailored screening and intervention strategies to prevent this common cancer.

Citation Format: Jihyoun Jeon, Sonja I. Berndt, Hermann Brenner, Peter T. Campbell, Andrew T. Chan, Jenny Chang-Claude, Mengmeng Du, Graham Giles, Jian Gong, Stephen B. Gruber, Tabitha A. Harrison, Michael Hoffmeister, Loic LeMarchand, Li Li, John D. Potter, Gad Rennert, Robert E. Schoen, Martha L. Slattery, Emily White, Michael O. Woods, Ulrike Peters, Li Hsu. Comprehensive colorectal cancer risk prediction to inform personalized screening and intervention. [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 2587.

Abstract LB-373: Plasma lipopolysaccharide-binding protein and colorectal cancer risk: A nested case-control study in the Multiethnic Cohort (MEC)

Lipopolysaccharide (LPS), an endotoxin found on the outer cell wall of gram-negative bacteria, increases inflammatory response signaling, and may play a role in the pathogenesis of several inflammatory-associated diseases, including cancer, diabetes, inflammatory bowel disease, and cardiovascular disease. While LPS is hypothesized to be associated with colorectal carcinogenesis, there are relatively few human studies which have examined this association. Thus, we examined the association between colorectal cancer (CRC) and lipopolysaccharide-binding protein (LBP; a marker of LPS) in 1,760 participants (879 CRC cases and 879 controls) from the Multiethnic Cohort study (MEC). The baseline questionnaire, which was administered between 1993 and 1996, obtained extensive information on demographics, medical and reproductive histories, cigarette smoking, medication use, family history of various cancers, physical activity, and diet using a quantitative food frequency questionnaire. LBP was measured in plasma samples collected between 2001-2005 and incident cancer cases were identified as those occurring after date of plasma collection through 2012 using the Hawaii Tumor Registry (HTR), the Los Angeles County Cancer Surveillance Program (CSP) and the State of California Cancer Registry (CCR), all of which are NCI-funded Surveillance, Epidemiology, and End Results (SEER) registries. Deaths in the cohort were identified by linkage to the state death-certificate files in CA and HI, and with the National Death Index for deaths occurring in other states. Controls were matched to incident cancer cases on age, location, sex, ethnicity, age at phlebotomy, date of specimen collection, time of blood collection, and time since last meal. LBP was grouped into tertiles, with the lowest tertile serving as the reference (mean: 20,797 ng/mL, range: 2,687-27,211 ng/mL). Conditional logistic regression models were used to estimate the multivariable-adjusted odds ratios (OR) and 95% confidence intervals (95% CI). Covariates were selected a priori and included factors associated with CRC: education, BMI (kg/m2), physical activity, smoking status at time of blood draw, history of intestinal polyps, previous colonoscopy or sigmoidoscopy, diabetes, history of CRC among 1st degree relatives, NSAID use, alcohol consumption, dietary fiber intake, saturated fat intake and hormone replacement therapy use. Compared to individuals whose LBP concentrations were in the lowest tertile, the ORs associated with middle (mean: 32,282 ng/mL, range: 27,211-37,777 ng/mL) and highest (mean: 51,019, range: 37,777-110,390 ng/mL) tertiles were 1.18 (95% CI = 0.85-1.64) and 1.31 (95% CI = 0.92-1.84), respectively, (Ptrend = 0.12). While this study did not find a statistically significant association between LBP and CRC, further studies are needed to understand the interplay between the gut microbiome, LBP, inflammation, and CRC.

This work was supported by grants from the National Institutes of Health (grants P01 CA168530, R25 CA094880, and P01 CA33619).

Citation Format: Jessica Citronberg, Lynne Wilkens, Loic Le Marchand, Unhee Lim, Meredith Hullar, Emily White, Polly Newcomb, Johanna Lampe. Plasma lipopolysaccharide-binding protein and colorectal cancer risk: A nested case-control study in the Multiethnic Cohort (MEC). [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 LB-373.

Abstract 5230: Large scale whole genome sequencing with imputation into GWAS improves our understanding of the genetic architecture of colorectal cancer

Whole-genome sequencing (WGS) has started a new era in human genetics in which data can be used to more fully understand the role of genetic variation in common complex diseases, including the role of less frequent and rare variants and structural variation. To explore the impact of these variants on colorectal cancer risk we conducted the first large scale WGS study for colorectal cancer (CRC) including 1,961 CRC cases and 981 controls. These WGS data as well as those from the Haplotype Reference Consortium were imputed in 13,104 CRC cases and 15,521 controls with genome-wide association study (GWAS) data that are part of the Colorectal Cancer Family Registry (CCFR) and the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO). Focusing on rare and less frequent variants, insertions and deletions we observed potentially novel variants: a less frequent variant (MAF = 0.026) on chromosome 5 located in NREP/STARD4-AS1 (p = value 4E-08); and a novel rare multi-allelic variant (MAF = 0.003) on chromosome 9 near KLF9 and TRPM3 (p-value 2E-09; the other allele of this multi-allelic variant had a MAF of 0.0003 and p-value of 0.55). Furthermore, we observed an independent locus close to the known region 8q24 that was located upstream of GSDMC (MAF = 0.16, p-value 5E-08). Within the known region 8q23/EIF3H we identified several low frequency variants with similar MAF (0.0181 to 0.0204) including a 6bp deletion with p-values between 4E-08 and 1E-09 that were independent of the common variant signal in this region. In addition, we identified statistically significant (p&lt;5E-08) deletions, insertions, and an essential splice site within known GWAS loci that present interesting candidates for functional studies. We will follow up these findings in independent samples from the Colorectal Cancer Transdisciplinary Study (CORECT) and CCFR, as well as additional samples currently genotyped in GECCO. In conclusion, next generation sequencing combined with imputation in large GWAS data sets has the potential to identify novel low frequency and rare genetic variants, aid fine-mapping of known CRC susceptibility loci and point to interesting functional candidates.

Citation Format: Jeroen Huyghe, Sai Chen, Hyun M. Kang, Tabitha A. Harrison, Sonja I. Berndt, Stephane Bézieau, Hermann Brenner, Graham Casey, Andrew T. Chan, Jenny Chang-Claude, Gallinger J. Steven, Stephen B. Gruber, Andrea Gsur, Michael Hoffmeister, Thomas J. Hudson, Loic Le Marchand, Polly A. Newcomb, John D. Potter, Conghui Qu, Martha L. Slattery, Joshua D. Smith, Emily White, Li Hsu, Goncalo R. Abecasis, Deborah A. Nickerson, Ulrike Peters. Large scale whole genome sequencing with imputation into GWAS improves our understanding of the genetic architecture of colorectal cancer. [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 5230.

Abstract 4284: Exploratory plasma proteomic analysis in a randomized cross-over trial of aspirin among healthy individuals

Background: Long-term use of aspirin is associated with lower colorectal cancer (CRC) incidence; however, the mechanism of the chemopreventive effect of aspirin is not fully understood. Animal studies suggest that COX-2, NFκB signaling and Wnt/β-catenin pathways may play a role, but no clinical trials have systematically evaluated the biological response to aspirin in healthy humans. Methods: We assessed the difference in plasma protein levels after 60 days of regular dose aspirin (325 mg/day) compared to placebo in a randomized, double-blinded, placebo-controlled, cross-over trial of 44 healthy non-smoking men and women, aged 21-45 years. Plasma proteomics was analyzed on an antibody microarray with ∼3,000 full-length antibodies, printed in triplicate. Moderated paired t-test was performed on individual antibodies, and gene set analyses were performed for KEGG and GO pathways. Results: Among the 3,387 antibodies, significant differences in plasma protein levels were observed for 267 antibodies (p&lt;0.05), the most significant protein being a transcription-factor regulator belonging to a steroid receptor family and found to be differentially expressed in colon cancer cells. Other significant proteins are involved in multiple oncogenic pathways related to colon tumorigenesis. In the pathway analysis, 4 KEGG (among 138) and 69 GO (among 1,089) pathways were found to be significant (p&lt;0.05), including natural killer (NK) cell-mediated cytotoxicity, butanoate metabolism and Wnt signaling pathways. Pathways that modulate cellular protein binding to steroid receptors were also significantly different between aspirin treatment and placebo (p&lt;0.05). None of the results remained statistically significant after correction for multiple testing. Conclusion: Several proteins and pathways, which have previously been reported as playing a role in colorectal carcinogenesis in vitro were found to be differentially expressed after aspirin treatment vs. placebo in healthy human subjects. This study suggests several chemopreventive mechanisms of aspirin; however, larger, confirmatory studies are needed.

Citation Format: Xiaoliang Wang, Yuzheng Zhang, Ali Shojaie, Paul D. Lampe, Lisa Levy, Ulrike Peters, John D. Potter, Emily White, Johanna W. Lampe. Exploratory plasma proteomic analysis in a randomized cross-over trial of aspirin among healthy individuals. [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 4284.

Abstract 4489: Using functional data from Roadmap Epigenomics to inform analysis of rare variants linked to gene expression in a large colorectal cancer study

To investigate the role of low frequency and rare genetic variation in colorectal cancer (CRC) susceptibility, the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO) and the Colorectal Cancer Family Registry (CCFR) conducted whole genome sequencing and imputed into genome-wide association studies (GWAS) of 14,718 CRC cases and 12,186 controls. These data provide a unique opportunity to investigate rare variants, which contribute to the majority of the variation in the genome. To improve power for discovering rare CRC susceptibility variants (&lt;1% MAF), Roadmap Epigenomics data were used to construct biologically relevant testing sets of enhancers, promoters and exons for gene-based association testing across the genome. Since enhancers exert their effects by impacting expression of target genes, we defined enhancer-gene networks by linking enhancer(s) to target gene expression using Roadmap chromatin state maps and gene expression. Variants in linked enhancers from digestive and immune tissues were aggregated together with variants in the promoter and non-synonymous coding variants in the target gene. We tested 9,884 variant sets for association with CRC risk using the Mixed effects Score Test (MiST). Our most significant findings are for acyl-Coenzyme A dehydrogenase, C-2 to C-3 short chain precursor-ACADS (p = 1×10−4), AlkB homologs, including AlkB homolog 1-ALKBH1 (p = 2×10−4), and SRA stem-loop interacting RNA binding protein-SLIRP (p = 2×10−4). We will replicate these findings within the Colorectal Cancer Transdisciplinary Study (CORECT), as well as additional samples currently genotyped in CCFR and GECCO (over 25,000 CRC cases and controls). Although the top findings are statistically non-significant in this initial dataset, each of these genes linked to molecular pathways implicated in CRC carcinogenesis (fatty acid metabolism, DNA/RNA repair, and Nuclear Receptor signaling pathway, which interacts with the Wnt, beta-catenin pathways to result in a diverse array of cellular effects including altered cellular adhesion, tissue morphogenesis, and oncogenesis). Our current findings suggest that although functional insight can improve power for novel discovery, even larger sample sizes and/or pathway-based analyses are necessary to understand the role of rare variants in CRC carcinogenesis.

Citation Format: Stephanie A. Bien, Tabitha A. Harrison, Paul L. Auer, Flora Qu, Jeroen Huyghe, Barbara Banbury, Peyton Greenside, Goncalo R. Abecasis, Sonja I. Berndt, Stephane Bézieau, Hermann Brenner, Graham Casey, Andrew T. Chan, Jenny Chang-Claude, Sai Chen, Joshua D. Smith, Loic Le Marchand, Christopher Carlson, Polly A. Newcomb, Christian Fuchsberger, Marty L. Slattery, Hyun M. Kang, Emily White, John Potter, Steven J. Gallinger, Michael Hoffmeister, Stephen B. Gruber, Deborah A. Nickerson, Ulrike Peters, Anshul Kundaje, Li Hsu. Using functional data from Roadmap Epigenomics to inform analysis of rare variants linked to gene expression in a large colorectal cancer study. [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 4489.

Reliability of plasma lipopolysaccharide-binding protein (LBP) from repeated measures in healthy adults

Plasma lipopolysaccharide-binding protein (LBP), a measure of internal exposure to bacterial lipopolysaccharide, has been associated with several chronic conditions and may be a marker of chronic inflammation; however, no studies have examined the reliability of this biomarker in a healthy population. We examined the temporal reliability of LBP measured in archived samples from participants in two studies. In Study one, 60 healthy participants had blood drawn at two time points: baseline and follow-up (either three, six, or nine months). In Study two, 24 individuals had blood drawn three to four times over a seven-month period. We measured LBP in archived plasma by ELISA. Test-retest reliability was estimated by calculating the intraclass correlation coefficient (ICC). Plasma LBP concentrations showed moderate reliability in Study one (ICC 0.60, 95 % CI 0.43-0.75) and Study two (ICC 0.46, 95 % CI 0.26-0.69). Restricting the follow-up period improved reliability. In Study one, the reliability of LBP over a three-month period was 0.68 (95 % CI: 0.41-0.87). In Study two, the ICC of samples taken ≤seven days apart was 0.61 (95 % CI 0.29-0.86). Plasma LBP concentrations demonstrated moderate test-retest reliability in healthy individuals with reliability improving over a shorter follow-up period.

International pooled study on diet and bladder cancer: the bladder cancer, epidemiology and nutritional determinants (BLEND) study: design and baseline characteristics

Background

In 2012, more than 400,000 urinary bladder cancer cases occurred worldwide, making it the 7^th most common type of cancer. Although many previous studies focused on the relationship between diet and bladder cancer, the evidence related to specific food items or nutrients that could be involved in the development of bladder cancer remains inconclusive. Dietary components can either be, or be activated into, potential carcinogens through metabolism, or act to prevent carcinogen damage.

Methods/design

The BLadder cancer, Epidemiology and Nutritional Determinants (BLEND) study was set up with the purpose of collecting individual patient data from observational studies on diet and bladder cancer. In total, data from 11,261 bladder cancer cases and 675,532 non-cases from 18 case–control and 6 cohort studies from all over the world were included with the aim to investigate the association between individual food items, nutrients and dietary patterns and risk of developing bladder cancer.

Discussion

The substantial number of cases included in this study will enable us to provide evidence with large statistical power, for dietary recommendations on the prevention of bladder cancer.

Fine-Mapping of Common Genetic Variants Associated with Colorectal Tumor Risk Identified Potential Functional Variants

Genome-wide association studies (GWAS) have identified many common single nucleotide polymorphisms (SNPs) associated with colorectal cancer risk. These SNPs may tag correlated variants with biological importance. Fine-mapping around GWAS loci can facilitate detection of functional candidates and additional independent risk variants. We analyzed 11,900 cases and 14,311 controls in the Genetics and Epidemiology of Colorectal Cancer Consortium and the Colon Cancer Family Registry. To fine-map genomic regions containing all known common risk variants, we imputed high-density genetic data from the 1000 Genomes Project. We tested single-variant associations with colorectal tumor risk for all variants spanning genomic regions 250-kb upstream or downstream of 31 GWAS-identified SNPs (index SNPs). We queried the University of California, Santa Cruz Genome Browser to examine evidence for biological function. Index SNPs did not show the strongest association signals with colorectal tumor risk in their respective genomic regions. Bioinformatics analysis of SNPs showing smaller P-values in each region revealed 21 functional candidates in 12 loci (5q31.1, 8q24, 11q13.4, 11q23, 12p13.32, 12q24.21, 14q22.2, 15q13, 18q21, 19q13.1, 20p12.3, and 20q13.33). We did not observe evidence of additional independent association signals in GWAS-identified regions. Our results support the utility of integrating data from comprehensive fine-mapping with expanding publicly available genomic databases to help clarify GWAS associations and identify functional candidates that warrant more onerous laboratory follow-up. Such efforts may aid the eventual discovery of disease-causing variant(s).

Effect of deploying community health assistants on appropriate treatment for diarrhoea, malaria and pneumonia: quasi-experimental study in two districts of Zambia

OBJECTIVE

A critical shortage of human resources for health in Zambia remains a great challenge. In response, the Zambian Ministry of Health developed a national community health assistant (CHA) programme, aiming to create a well-trained and motivated community-based health workforce. This study assessed whether CHAs increased treatment rates for diarrhoea, confirmed malaria or pneumonia in the first programme year.

METHODS

This study used a quasi-experimental difference-in-difference design, comparing changes in the catchment areas of health posts with CHAs to those without. Baseline and end line household surveys were conducted to measure the proportion of children under 5 years treated for diarrhoea, malaria or pneumonia in the 2 weeks before the survey and immunisation rates and malaria rapid diagnostic test rates.

RESULTS

We surveyed 2330 women with children under five from the intervention area and 2314 from comparison areas at baseline and end line. Treatment for diarrhoea, malaria or pneumonia increased by 18.0% (P < 0.01) and 23.5% (P < 0.01) in the intervention and comparison groups, respectively, but DID analysis was not significant (P = 0.27). The proportion of fully immunised children grew by 7.5% in the intervention, but shrank by 7.5% in the comparison group (DID: 0.14; 95% CI 0.12-0.16, P < 0.01).

CONCLUSION

Although we observed no significant difference between the intervention and comparison groups in the DID estimates for the primary outcome, there were significant increases after one year in treatment for all three diseases in the intervention group from baseline to end line and in the proportion of fully immunised children.

Female chromosome X mosaicism is age-related and preferentially affects the inactivated X chromosome

To investigate large structural clonal mosaicism of chromosome X, we analysed the SNP microarray intensity data of 38,303 women from cancer genome-wide association studies (20,878 cases and 17,425 controls) and detected 124 mosaic X events >2 Mb in 97 (0.25%) women. Here we show rates for X-chromosome mosaicism are four times higher than mean autosomal rates; X mosaic events more often include the entire chromosome and participants with X events more likely harbour autosomal mosaic events. X mosaicism frequency increases with age (0.11% in 50-year olds; 0.45% in 75-year olds), as reported for Y and autosomes. Methylation array analyses of 33 women with X mosaicism indicate events preferentially involve the inactive X chromosome. Our results provide further evidence that the sex chromosomes undergo mosaic events more frequently than autosomes, which could have implications for understanding the underlying mechanisms of mosaic events and their possible contribution to risk for chronic diseases.

It is unclear how often genetic mosaicism of chromosome X arises. Here, the authors examine women with cancer and cancer-free controls and show that X chromosome mosaicism occurs more frequently than on autosomes, especially on the inactive X chromosome, but is not linked to non-haematologic cancer risk

Relationship of prediagnostic body mass index with survival after colorectal cancer: Stage-specific associations

Higher body mass index (BMI) is a well-established risk factor for colorectal cancer (CRC), but is inconsistently associated with CRC survival. In 6 prospective studies participating in the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), 2,249 non-Hispanic white CRC cases were followed for a median 4.5 years after diagnosis, during which 777 died, 554 from CRC-related causes. Associations between prediagnosis BMI and survival (overall and CRC-specific) were evaluated using Cox regression models adjusted for age at diagnosis, sex, study and smoking status (current/former/never). The association between BMI category and CRC survival varied by cancer stage at diagnosis (I-IV) for both all-cause (p-interaction = 0.03) and CRC-specific mortality (p-interaction = 0.04). Compared to normal BMI (18.5-24.9 kg/m(2) ), overweight (BMI 25.0-29.9) was associated with increased mortality among those with Stage I disease, and decreased mortality among those with Stages II-IV disease. Similarly, obesity (BMI ≥30) was associated with increased mortality among those with Stages I-II disease, and decreased mortality among those with Stages III-IV disease. These results suggest the relationship between BMI and survival after CRC diagnosis differs by stage at diagnosis, and may emphasize the importance of adequate metabolic reserves for colorectal cancer survival in patients with late-stage disease.

Comprehensive Genomic Profiling of Carcinoma of Unknown Primary Site: New Routes to Targeted Therapies

IMPORTANCE

For carcinoma of unknown primary site (CUP), determining the primary tumor site may be uninformative and often does not improve outcome.

OBJECTIVE

To discover opportunities for targeted therapies in patients with CUP not currently searched for in routine practice.

DESIGN, SETTING, AND PARTICIPANTS

Comprehensive genomic profiling on 200 CUP formalin-fixed paraffin-embedded specimens (mean, 756× coverage) using the hybrid-capture-based FoundationOne assay at academic and community oncology clinics.

MAIN OUTCOMES AND MEASURES

Presence of targetable genomic alterations (GAs) in CUP and responses to targeted therapies.

RESULTS

There were 125 adenocarcinomas of unknown primary site (ACUPs) and 75 carcinomas of unknown primary site without features of adenocarcinoma (non-ACUPs). At least 1 GA was found in 192 (96%) of CUP specimens, with a mean (SD) of 4.2 (2.8) GAs per tumor. The most frequent GAs were in TP53 (110 [55%]), KRAS (40 [20%]), CDKN2A (37 [19%]), MYC (23 [12%]), ARID1A (21 [11%]), MCL1 (19 [10%]), PIK3CA (17 [9%]), ERBB2 (16 [8%]), PTEN (14 [7%]), EGFR (12 [6%]), SMAD4 (13 [7%]), STK11 (13 [7%]), SMARCA4 (12 [6%]), RB1 (12 [6%]), RICTOR (12 [6%]), MLL2 (12 [6%]), BRAF (11 [6%]), and BRCA2 (11 [6%]). One or more potentially targetable GAs were identified in 169 of 200 (85%) CUP specimens. Mutations or amplifications of ERBB2 were more frequent in ACUPs (13 [10%]) than in non-ACUPs (3 [4%]). Alterations of EGFR (10 [8%] vs 2 [3%]) and BRAF (8 [6%] vs 3 [4%]) were more common in ACUPs than in non-ACUPs. Strikingly, clinically relevant alterations in the receptor tyrosine kinase (RTK)/Ras signaling pathway including alterations in ALK, ARAF, BRAF, EGFR, FGFR1, FGFR2, KIT, KRAS, MAP2K1, MET, NF1, NF2, NRAS, RAF1, RET, and ROS1 were found in 90 (72%) ACUPs but in only 29 (39%) non-ACUPs (P < .001).

CONCLUSIONS AND RELEVANCE

Almost all CUP samples harbored at least 1 clinically relevant GA with potential to influence and personalize therapy. The ACUP tumors were more frequently driven by GAs in the highly druggable RTK/Ras/mitogen-activated protein kinase (MAPK) signaling pathway than the non-ACUP tumors. Comprehensive genomic profiling can identify novel treatment paradigms to address the limited options and poor prognoses of patients with CUP.

Anthropometric Factors and Thyroid Cancer Risk by Histological Subtype: Pooled Analysis of 22 Prospective Studies

BACKGROUND

Greater height and body mass index (BMI) have been associated with an increased risk of thyroid cancer, particularly papillary carcinoma, the most common and least aggressive subtype. Few studies have evaluated these associations in relation to other, more aggressive histologic types or thyroid cancer-specific mortality.

METHODS

This large pooled analysis of 22 prospective studies (833,176 men and 1,260,871 women) investigated thyroid cancer incidence associated with greater height, BMI at baseline and young adulthood, and adulthood BMI gain (difference between young-adult and baseline BMI), overall and separately by sex and histological subtype using multivariable Cox proportional hazards regression models. Associations with thyroid cancer mortality were investigated in a subset of cohorts (578,922 men and 774,373 women) that contributed cause of death information.

RESULTS

During follow-up, 2996 incident thyroid cancers and 104 thyroid cancer deaths were identified. All anthropometric factors were positively associated with thyroid cancer incidence: hazard ratios (HR) [confidence intervals (CIs)] for height (per 5 cm) = 1.07 [1.04-1.10], BMI (per 5 kg/m2) = 1.06 [1.02-1.10], waist circumference (per 5 cm) = 1.03 [1.01-1.05], young-adult BMI (per 5 kg/m2) = 1.13 [1.02-1.25], and adulthood BMI gain (per 5 kg/m2) = 1.07 [1.00-1.15]. Associations for baseline BMI and waist circumference were attenuated after mutual adjustment. Baseline BMI was more strongly associated with risk in men compared with women (p = 0.04). Positive associations were observed for papillary, follicular, and anaplastic, but not medullary, thyroid carcinomas. Similar, but stronger, associations were observed for thyroid cancer mortality.

CONCLUSION

The results suggest that greater height and excess adiposity throughout adulthood are associated with higher incidence of most major types of thyroid cancer, including the least common but most aggressive form, anaplastic carcinoma, and higher thyroid cancer mortality. Potential underlying biological mechanisms should be explored in future studies.

CYP24A1 variant modifies the association between use of oestrogen plus progestogen therapy and colorectal cancer risk

BACKGROUND

Menopausal hormone therapy (MHT) use has been consistently associated with a decreased risk of colorectal cancer (CRC) in women. Our aim was to use a genome-wide gene-environment interaction analysis to identify genetic modifiers of CRC risk associated with use of MHT.

METHODS

We included 10 835 postmenopausal women (5419 cases and 5416 controls) from 10 studies. We evaluated use of any MHT, oestrogen-only (E-only) and combined oestrogen-progestogen (E+P) hormone preparations. To test for multiplicative interactions, we applied the empirical Bayes (EB) test as well as the Wald test in conventional case-control logistic regression as primary tests. The Cocktail test was used as secondary test.

RESULTS

The EB test identified a significant interaction between rs964293 at 20q13.2/CYP24A1 and E+P (interaction OR (95% CIs)=0.61 (0.52-0.72), P=4.8 × 10(-9)). The secondary analysis also identified this interaction (Cocktail test OR=0.64 (0.52-0.78), P=1.2 × 10(-5) (alpha threshold=3.1 × 10(-4)). The ORs for association between E+P and CRC risk by rs964293 genotype were as follows: C/C, 0.96 (0.61-1.50); A/C, 0.61 (0.39-0.95) and A/A, 0.40 (0.22-0.73), respectively.

CONCLUSIONS

Our results indicate that rs964293 modifies the association between E+P and CRC risk. The variant is located near CYP24A1, which encodes an enzyme involved in vitamin D metabolism. This novel finding offers additional insight into downstream pathways of CRC etiopathogenesis.

Factors Associated with Multiple Biomarkers of Systemic Inflammation

BACKGROUND

While much is known about correlates of C-reactive protein (CRP), little is known about correlates of other inflammation biomarkers. As these measures are increasingly being used in epidemiologic studies, it is important to determine what factors affect inflammation biomarker concentrations.

METHODS

Using age, sex, and body mass index (BMI) adjusted linear regression, we examined 38 exposures (demographic and anthropometric measures, chronic disease history, NSAIDs, dietary factors, and supplement use) of 8 inflammation biomarkers [CRP, IL1β, IL6, IL8, TNFα, and soluble TNF receptors (sTNFR) in plasma; and prostaglandin E2 metabolite (PGE-M) in urine] in 217 adults, ages 50 to 76 years.

RESULTS

Increasing age was associated with higher concentrations of all biomarkers except IL1β. BMI was positively associated with CRP and sTNFR I and II. Saturated fat intake was associated with increased CRP, sTNFRII, TNFα, and IL1β, whereas eicosapentaenoic acid + docosahexaenoic acid (EPA+DHA) intake (diet or total) was associated with decreased CRP, TNFα, and IL1β. Results for sex were varied: CRP and IL6 were lower among men, whereas PGE-M and sTNFRI were higher. Higher CRP was also associated with smoking, hormone replacement therapy use, and γ-tocopherol intake; lower CRP with physical activity, and intakes of dietary vitamin C and total fiber.

CONCLUSIONS

Although the associations varied by biomarker, the factors having the greatest number of significant associations (P ≤ 0.05) with the inflammation biomarkers were age, BMI, dietary saturated fat, and EPA+DHA omega-3 fatty acids.

IMPACT

Our results suggest that potential confounders in epidemiologic studies assessing associations with inflammation biomarkers vary across specific biomarkers.

Novel Inducers of Fetal Globin Identified through High Throughput Screening (HTS) Are Active In Vivo in Anemic Baboons and Transgenic Mice

High-level fetal (γ) globin expression ameliorates clinical severity of the beta (β) hemoglobinopathies, and safe, orally-bioavailable γ-globin inducing agents would benefit many patients. We adapted a LCR-γ-globin promoter-GFP reporter assay to a high-throughput robotic system to evaluate five diverse chemical libraries for this activity. Multiple structurally- and functionally-diverse compounds were identified which activate the γ-globin gene promoter at nanomolar concentrations, including some therapeutics approved for other conditions. Three candidates with established safety profiles were further evaluated in erythroid progenitors, anemic baboons and transgenic mice, with significant induction of γ-globin expression observed in vivo. A lead candidate, Benserazide, emerged which demonstrated > 20-fold induction of γ-globin mRNA expression in anemic baboons and increased F-cell proportions by 3.5-fold in transgenic mice. Benserazide has been used chronically to inhibit amino acid decarboxylase to enhance plasma levels of L-dopa. These studies confirm the utility of high-throughput screening and identify previously unrecognized fetal globin inducing candidates which can be developed expediently for treatment of hemoglobinopathies.

Antiretroviral resistance at virological failure in the NEAT 001/ANRS 143 trial: raltegravir plus darunavir/ritonavir or tenofovir/emtricitabine plus darunavir/ritonavir as first-line ART

OBJECTIVES

To describe the pattern of drug resistance at virological failure in the NEAT001/ANRS143 trial (first-line treatment with ritonavir-boosted darunavir plus either tenofovir/emtricitabine or raltegravir).

METHODS

Genotypic testing was performed at baseline for reverse transcriptase (RT) and protease genes and for RT, protease and integrase (IN) genes for patients with a confirmed viral load (VL) >50 copies/mL or any single VL >500 copies/mL during or after week 32.

RESULTS

A resistance test was obtained for 110/805 (13.7%) randomized participants qualifying for resistance analysis (61/401 of participants in the raltegravir arm and 49/404 of participants in the tenofovir/emtricitabine arm). No resistance-associated mutation (RAM) was observed in the tenofovir/emtricitabine plus darunavir/ritonavir arm, and all further analyses were limited to the raltegravir plus darunavir arm. In this group, 15/55 (27.3%) participants had viruses with IN RAMs (12 N155H alone, 1 N155H + Q148R, 1 F121Y and 1 Y143C), 2/53 (3.8%) with nucleotide analogue RT inhibitor RAMs (K65R, M41L) and 1/57 (1.8%) with primary protease RAM (L76V). The frequency of IN mutations at failure was significantly associated with baseline VL: 7.1% for a VL of <100,000 copies/mL, 25.0% for a VL of ≥100,000 copies/mL and <500,000 copies/mL and 53.8% for a VL of ≥500,000 copies/mL (PTREND = 0.007). Of note, 4/15 participants with IN RAM had a VL < 200 copies/mL at time of testing.

CONCLUSIONS

In the NEAT001/ANRS143 trial, there was no RAM at virological failure in the standard tenofovir/emtricitabine plus darunavir/ritonavir regimen, contrasting with a rate of 29.5% (mostly IN mutations) in the raltegravir plus darunavir/ritonavir NRTI-sparing regimen. The cumulative risk of IN RAM after 96 weeks of follow-up in participants initiating ART with raltegravir plus darunavir/ritonavir was 3.9%.

Magnesium intake and incidence of pancreatic cancer: the VITamins and Lifestyle study

BACKGROUND

Studies document that magnesium is inversely associated with the risk of diabetes, which is a risk factor of pancreatic cancer. However, studies on the direct association of magnesium with pancreatic cancer are few and findings are inconclusive. In this study, we aimed to investigate the longitudinal association between magnesium intake and pancreatic cancer incidence in a large prospective cohort study.

METHOD

A cohort of 66,806 men and women aged 50-76 years at baseline who participated in the VITamins And Lifestyle (VITAL) study was followed from 2000 to 2008. Multivariable-adjusted Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of pancreatic cancer incidence by magnesium intake categories.

RESULT

During an average of 6.8-year follow-up, 151 participants developed pancreatic cancer. Compared with those who met the recommended dietary allowance (RDA) for magnesium intake, the multivariable-adjusted HRs (95% CIs) for pancreatic cancer were 1.42 (0.91, 2.21) for those with magnesium intake in the range of 75-99% RDA and 1.76 (1.04, 2.96) for those with magnesium intake <75% RDA. Every 100 mg per day decrement in magnesium intake was associated with a 24% increase in the incidence of pancreatic cancer (HR: 1.24; 95% CI: 1.02, 1.50; P(trend)=0.03). The observed inverse associations appeared not to be appreciably modified by age, gender, body mass index, and non-steroidal anti-inflammatory drug use but appeared to be limited to those taking magnesium supplementation (from multivitamins or individual supplement).

CONCLUSIONS

Findings from this prospective cohort study indicate that magnesium intake may be beneficial in terms of primary prevention of pancreatic cancer.

Analysis of Heritability and Shared Heritability Based on Genome-Wide Association Studies for Thirteen Cancer Types

BACKGROUND

Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites.

METHODS

Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers.

RESULTS

GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, hl (2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (ρ = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (ρ = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (ρ = 0.51, SE =0.18), and bladder and lung (ρ = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures.

CONCLUSION

Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation.

Contribution of health behaviors to the association between area-level socioeconomic status and cancer mortality

Cancer mortality is higher among residents of low-socioeconomic status (SES) areas than those of high-SES areas; however, the contribution of modifiable risk factors to this disparity is not known. We used data from 54,737 participants in the VITamins And Lifestyle (VITAL) Study, aged 50-76 with no history of cancer at baseline (2000-2002). Of these, 1488 died of cancer over an average of 7.7 years of follow-up. Data on modifiable risk factors including body mass index (BMI), physical activity, diet, alcohol, smoking and screening were taken from baseline questionnaires. We constructed a block group-level SES index using data from the 2000 United States Census and fit Cox proportional hazards models estimating the association between area-level SES and total cancer mortality with and without control for modifiable risk factors. All statistical tests are 2-sided. Cancer mortality was 77% (95% CI: 50%, 111%) higher in the lowest-SES areas compared with the highest. Modifiable risk factors accounted for 45% (95% CI: 34%, 62%) of this association. Smoking explained the greatest proportion (29%; 95% CI: 22%, 40%) of the observed association, followed by diet (11%; 95% CI: 7%, 17%), physical activity (10%; 95% CI: 7%, 16%), screening (9%; 6%, 13%), and BMI (5%; 95% CI: 1%, 10%). Results were similar in models controlling for individual education and income. The association between area-level SES and cancer mortality is partially explained by modifiable risk factors, which could suggest the appropriate targets to reduce socioeconomic disparities.

Common genetic variation and survival after colorectal cancer diagnosis: a genome-wide analysis

Genome-wide association studies have identified several germline single nucleotide polymorphisms (SNPs) significantly associated with colorectal cancer (CRC) incidence. Common germline genetic variation may also be related to CRC survival. We used a discovery-based approach to identify SNPs related to survival outcomes after CRC diagnosis. Genome-wide genotyping arrays were conducted for 3494 individuals with invasive CRC enrolled in six prospective cohort studies (median study-specific follow-up = 4.2-8.1 years). In pooled analyses, we used Cox regression to assess SNP-specific associations with CRC-specific and overall survival, with additional analyses stratified by stage at diagnosis. Top findings were followed-up in independent studies. A P value threshold of P < 5×10(-8) in analyses combining discovery and follow-up studies was required for genome-wide significance. Among individuals with distant-metastatic CRC, several SNPs at 6p12.1, nearest the ELOVL5 gene, were statistically significantly associated with poorer survival, with the strongest associations noted for rs209489 [hazard ratio (HR) = 1.8, P = 7.6×10(-10) and HR = 1.8, P = 3.7×10(-9) for CRC-specific and overall survival, respectively). No SNPs were statistically significantly associated with survival among all cases combined or in cases without distant-metastases. SNPs in 6p12.1/ELOVL5 were associated with survival outcomes in individuals with distant-metastatic CRC, and merit further follow-up for functional significance. Findings from this genome-wide association study highlight the potential importance of genetic variation in CRC prognosis and provide clues to genomic regions of potential interest.

Global HIV-1 transmitted drug resistance in the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial

OBJECTIVES

HIV-1 transmitted drug resistance (TDR) in treatment-naïve individuals is a well-described phenomenon. Baseline genotypic resistance testing is considered standard of care in most developed areas of the world. The aim of this analysis was to characterize HIV-1 TDR and the use of resistance testing in START trial participants.

METHODS

In the Strategic Timing of AntiRetroviral Treatment (START) trial, baseline genotypic resistance testing results were collected at study entry and analysed centrally to determine the prevalence of TDR in the study population. Resistance was based on a modified 2009 World Health Organization definition to reflect newer resistance mutations.

RESULTS

Baseline resistance testing was available in 1946 study participants. Higher rates of testing occurred in Europe (86.7%), the USA (81.3%) and Australia (89.9%) as compared with Asia (22.2%), South America (1.8%) and Africa (0.1%). The overall prevalence of TDR was 10.1%, more commonly to nonnucleoside reverse transcriptase inhibitors (4.5%) and nucleoside reverse transcriptase inhibitors (4%) compared with protease inhibitors (2.8%). The most frequent TDR mutations observed were M41L, D67N/G/E, T215F/Y/I/S/C/D/E/V/N, 219Q/E/N/R, K103N/S, and G190A/S/E in reverse transcriptase, and M46I/L and L90M in protease. By country, the prevalence of TDR was highest in Australia (17.5%), France (16.7%), the USA (12.6%) and Spain (12.6%). No participant characteristics were identified as predictors of the presence of TDR.

CONCLUSIONS

START participants enrolled in resource-rich areas of the world were more likely to have baseline resistance testing. In Europe, the USA and Australia, TDR prevalence rates varied by country.

Obesity and inflammation markers in relation to leukocyte telomere length in a cross-sectional study of persons with Barrett's esophagus

BACKGROUND

Telomere shortening is associated with increasing age, male gender and lifestyle factors such as obesity and smoking. Inflammation has also been implicated in cellular senescence and may promote telomere shortening in chronic conditions such as obesity and diabetes. However, little is known about the relationship between markers of obesity and inflammation, and leukocyte telomere length (LTL).

METHODS

LTL was measured using quantitative polymerase chain reaction in peripheral leukocytes from 295 individuals diagnosed with Barrett's esophagus (BE) between 1995 and 2009. Data on lifestyle variables including obesity and smoking were collected at in-person interviews. Biomarkers of obesity (leptin, adiponectin), diabetes (glucose, insulin), inflammation (C-reactive protein, Interleukin-6, surface tumor necrosis factor receptor (sTNFR) I & II) and oxidative stress (F2-isoprostanes) were measured in stored blood samples. We examined associations between these covariates and LTL in a cross-sectional analysis using linear and logistic regression models, adjusting for possible confounders.

RESULTS

LTL was significantly associated with age (r = -0.30, p < 0.001), gender (r = 0.14 for females, p = 0.01) and inversely associated with cigarette pack-years (r = -0.11, p = 0.04). Odds of having short LTL were significantly higher for participants in the highest tertile for sTNF-RI (Odds ratio adjusted for age, gender, smoking, and obesity = 2.19; 95 % CI 1.00-4.85, p-trend = 0.02). LTL was not significantly associated with any other lifestyle factors, including smoking or obesity, or other inflammation-, obesity-/diabetes-related biomarkers measured.

CONCLUSIONS

Increasing age, male gender, smoking history, and sTNF-RI levels were associated with short LTL among persons with BE but no correlations were observed between LTL and other inflammatory markers or measures of obesity. Larger longitudinal studies are necessary in order to further establish the potential relationships between obesity, inflammation markers and LTL.

Central adiposity, obesity during early adulthood, and pancreatic cancer mortality in a pooled analysis of cohort studies

BACKGROUND

Body mass index (BMI), a measure of obesity typically assessed in middle age or later, is known to be positively associated with pancreatic cancer. However, little evidence exists regarding the influence of central adiposity, a high BMI during early adulthood, and weight gain after early adulthood on pancreatic cancer risk.

DESIGN

We conducted a pooled analysis of individual-level data from 20 prospective cohort studies in the National Cancer Institute BMI and Mortality Cohort Consortium to examine the association of pancreatic cancer mortality with measures of central adiposity (e.g. waist circumference; n = 647 478; 1947 pancreatic cancer deaths), BMI during early adulthood (ages 18-21 years) and BMI change between early adulthood and cohort enrollment, mostly in middle age or later (n = 1 096 492; 3223 pancreatic cancer deaths). Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards regression models.

RESULTS

Higher waist-to-hip ratio (HR = 1.09, 95% CI 1.02-1.17 per 0.1 increment) and waist circumference (HR = 1.07, 95% CI 1.00-1.14 per 10 cm) were associated with increased risk of pancreatic cancer mortality, even when adjusted for BMI at baseline. BMI during early adulthood was associated with increased pancreatic cancer mortality (HR = 1.18, 95% CI 1.11-1.25 per 5 kg/m(2)), with increased risk observed in both overweight and obese individuals (compared with BMI of 21.0 to <23 kg/m(2), HR = 1.36, 95% CI 1.20-1.55 for BMI 25.0 < 27.5 kg/m(2), HR = 1.48, 95% CI 1.20-1.84 for BMI 27.5 to <30 kg/m(2), HR = 1.43, 95% CI 1.11-1.85 for BMI ≥30 kg/m(2)). BMI gain after early adulthood, adjusted for early adult BMI, was less strongly associated with pancreatic cancer mortality (HR = 1.05, 95% CI 1.01-1.10 per 5 kg/m(2)).

CONCLUSIONS

Our results support an association between pancreatic cancer mortality and central obesity, independent of BMI, and also suggest that being overweight or obese during early adulthood may be important in influencing pancreatic cancer mortality risk later in life.

Abstract AS10: Ovarian cancer risk factor associations by tumor aggressiveness in the ovarian cancer cohort consortium (OC3)

Introduction: Ovarian cancer is a heterogeneous disease with about half of patients dying within 3 years, but a third surviving at least 10 years, potentially reflecting differences not only for stage, but also in tumor biology. We evaluated if known and putative ovarian cancer risk factors were differentially associated with tumor aggressiveness, defined as rapidly fatal (death within 3 years) and less aggressive (all others). We assessed oral contraceptive (OC) use, parity, tubal ligation, height, body mass index (BMI), family history of breast or ovarian cancer, age at menarche and menopause, and smoking using pooled data from 18 prospective cohort studies.

Methods: Ovarian cancer characteristics and diagnosis dates were abstracted from pathology reports or cancer registries; registries were used to ascertain vital status and date of death. We used competing risks Cox proportional hazards models to compute relative risks (RR) and 95% confidence intervals (CI) by tumor aggressiveness, stratified on study, age, and birth year, and adjusted for parity and OC use; p-heterogeneity (p-het) was evaluated by likelihood ratio tests.

Results: Among 3,811 cases with known vital status and the potential for at least 3 years of post-diagnosis follow-up, 1,897 (49.8%; median survival=1yr) were rapidly fatal and 1,914 (50.2%; median survival=18yr) were less aggressive. 66% of rapidly fatal and 55% of less aggressive cases were of serous histology. Stronger inverse associations were observed for less aggressive than for rapidly fatal disease for tubal ligation (RR, yes vs. no=0.67 vs. 1.06, respectively; p-het=0.004), parity (RR, per child=0.87 vs. 0.93; p-het=0.001) pack years of smoking (RR, &gt;30 pack-years vs. never=0.78 vs. 1.14; p-het=0.01), and suggestively for family history of breast cancer (RR, yes vs. no=1.15 vs. 0.99, p-het=0.18). Conversely, women with a BMI&gt;30 vs. &gt;22-25 kg/m2 were at higher risk of rapidly fatal disease (RR=1.40), but not less aggressive disease (RR=1.00; p-het=0.04). Associations for other risk factors did not differ by aggressiveness.

Discussion: In this prospective analysis, we observed differential associations by tumor aggressiveness for some risk factors. The potentially stronger association of a family history of breast cancer with less aggressive disease is supported by reports of better survival in BRCA mutation carriers. Associations of parity, tubal ligation, and smoking with less aggressive disease may reflect differential associations by histology; additional analyses will account for histology and stage. The BMI association with rapidly fatal disease suggests that metabolic dysfunction may play a role in tumor aggressiveness. Our results support that pre-diagnostic factors may influence ovarian cancer development and aggressivness. Ultimately, understanding a woman's risk profile with respect to risk of rapidly fatal versus less aggressive disease at diagnosis may aid in determining the most optimal treatment strategy for long term survival.

Citation Format: Shelley S. Tworoger, Elizabeth M. Poole, Alan A. Arslan, Lesley M. Butler, Victoria Kirsh, James V. Lacey, Jr., I-Min Lee, Alpa V. Patel, Kim Robien, Thomas Rohan, Dale P. Sandler, Leo J. Schouten, V. Wendy Setiawan, Kala Visvanathan, Elisabete Weiderpass, Emily White, Nicolas Wentzensen, for the OC3. Ovarian cancer risk factor associations by tumor aggressiveness in the ovarian cancer cohort consortium (OC3) [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr AS10.

Abstract 862: Association of non-steroidal anti-inflammatory drugs with colorectal cancer by subgroups in the Vitamins and Lifestyle (VITAL) Study

Background: There is substantial evidence that use of non-steroidal anti-inflammatory drugs (NSAIDs) reduces the risk of colorectal cancer (CRC), but no subgroup has been identified for which the chemoprevention effect outweighs the risk of side effects. Methods: We tested the interaction between NSAID use and multiple risk factors on CRC risk in the VITAL cohort. A total of 73,458 individuals aged 50-76 completed a questionnaire between 2000 and 2002, and 674 incidental colorectal cancer cases were identified through 2010. Results: In stratified analysis, high use of any type of NSAIDs (4+days/week for 4+ years) was statistically significantly associated with a lower risk of CRC across all subgroups stratified by sex, BMI, physical activity, smoking, alcohol intake, screening and dietary factors, with a suggestion of stronger association among men, obese individuals, and heavier drinkers; however, none of these tests for interaction reached statistical significance. The associations were almost identical for subjects with higher overall CRC risk scores (HR: 0.62; 95% CI: 0.49-0.79) and those with lower risk scores (HR: 0.61; 95% CI: 0.42-0.88). Differential effects by cancer subsites and stages were tested. NSAID use was associated with a greater risk reduction of proximal colon cancer vs distal (p for difference = 0.06) and distant stage vs local (p for difference = 0.04). Conclusion: The association between high use of NSAIDs and CRC risk does not differ significantly among subgroups. Impact: Our results suggest that NSAIDs have a generally beneficial role in colorectal cancer prevention, largely unmodified by other exposures.

Citation Format: Xiaoliang Wang, Ulrike Peters, John D. Potter, Emily White. Association of non-steroidal anti-inflammatory drugs with colorectal cancer by subgroups in the Vitamins and Lifestyle (VITAL) Study. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 862. doi:10.1158/1538-7445.AM2015-862

Abstract 854: Ovarian cancer risk factors by histologic subtypes: evidence for etiologic heterogeneity

Background: A subset of high grade serous carcinomas may arise from the fallopian tube, while some endometrioid and clear cell carcinomas may derive from endometrial tissue. Previous studies have suggested differences in ovarian cancer risk factors by histologic subtypes, but had limited sample sizes. In the Ovarian Cancer Cohort Consortium (OC3), we evaluated associations of reproductive, hormonal, demographic and lifestyle factors, and family history of cancer with ovarian cancer subtypes. Identification of potential differences in associations among subtypes is important for clarifying ovarian cancer etiology and for developing novel prevention and risk prediction approaches.

Methods: Among over 1.2 million women from 21 cohort studies, 4,347 ovarian cancers with histology information were identified during follow-up (3223 serous, 555 endometrioid, 316 mucinous, 253 clear cell). We used competing risks Cox proportional hazards regression to compute risk factor associations by histologic subtype. Models were stratified on study and year of birth and adjusted for age, parity and oral contraceptive use; subtype heterogeneity was evaluated by a likelihood ratio test. Unsupervised hierarchical clustering was used to evaluate patterns of risk factors by histology.

Results: Most risk factors showed significant heterogeneity across histologic subtypes. Higher parity was most strongly associated with lower risks of endometrioid (RR per child: 0.79; 95%CI: 0.74-0.85) and clear cell (RR: 0.69; 95%CI: 0.61-0.78) carcinomas (p-het&lt;0.0001). Age at menopause was positively and tubal ligation was inversely associated only with endometrioid and clear cell carcinomas (p-het = 0.02 and 0.003, respectively). Long-term menopausal hormone use (&gt;5 years) was associated with endometrioid carcinomas (RR: 2.23; 95% CI: 1.46-3.42) and serous carcinomas (RR: 1.66; 95% CI: 1.44-1.92), and inversely associated with clear cell carcinomas (RR: 0.43; 95% CI: 0.20-0.91; p-het = 0.001). Family history of breast cancer was associated with increased risk of serous carcinomas (RR:1.13; 95% CI:1.02-1.27) and endometrioid carcinomas (RR: 1.44; 95% CI: 1.12-1.87; p-het = 0.02). Smoking (per 20 pack years) showed a positive association with mucinous carcinomas (RR: 1.38; 95% CI: 1.09-1.75) and an inverse association with clear cell carcinomas (RR:0.62; 95% CI: 0.46-0.85; p-het = 0.001). In unsupervised hierarchical clustering, serous and mucinous carcinomas clustered in one group and endometrioid and clear cell carcinomas in the other.

Conclusion: Our results demonstrate heterogeneous associations of risk factors with ovarian cancer subtypes, supporting the hypothesis that the subtypes develop through different pathways. Most established risk factors were more strongly associated with non-serous carcinomas, suggesting that risk prediction may be more challenging for serous cancers, the most fatal subtype.

Citation Format: Nicolas A. Wentzensen, Elizabeth Poole, Alan A. Arslan, Alpa V. Patel, V Wendy Setiawan, Kala Visvanathan, Elisabete Weiderpass, Emily White, Hans-Olov Adami, Louise A. Brinton, Leslie Bernstein, Julie Buring, Lesley M. Butler, Saioa Chamosa, Tess V. Clendenen, Laure Dossus, Renee Fortner, Susan M. Gapstur, Mia M. Gaudet, Inger Torhild Gram, Patricia Hartge, Judith Hoffman-Bolton, Annika Idahl, Michael Jones, Rudolf Kaaks, Vivki Kirsh, Woon-Puay Koh, James V. Lacey, I-Min Lee, Eva Lundin, Melissa Merritt, Ulrike Peters, Jenny Poynter, Sabina Rinaldi, Kim Robien, Thomas Rohan, Dale P. Sandler, Leo J. Schouten, Louise Sjöholm, Sabina Sieri, Anthony Swerdlow, Anne Tjønneland, Britton Trabert, Lynne Wilkens, Alicja Wolk, Hannah P. Yang, Anne Zeleniuch-Jacquotte, Shelley S. Tworoger. Ovarian cancer risk factors by histologic subtypes: evidence for etiologic heterogeneity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 854. doi:10.1158/1538-7445.AM2015-854

Identification of a common variant with potential pleiotropic effect on risk of inflammatory bowel disease and colorectal cancer

Although genome-wide association studies (GWAS) have separately identified many genetic susceptibility loci for ulcerative colitis (UC), Crohn's disease (CD) and colorectal cancer (CRC), there has been no large-scale examination for pleiotropy, or shared genetic susceptibility, for these conditions. We used logistic regression modeling to examine the associations of 181 UC and CD susceptibility variants previously identified by GWAS with risk of CRC using data from the Genetics and Epidemiology of Colorectal Cancer Consortium and the Colon Cancer Family Registry. We also examined associations of significant variants with clinical and molecular characteristics in a subset of the studies. Among 11794 CRC cases and 14190 controls, rs11676348, the susceptibility single nucleotide polymorphism (SNP) for UC, was significantly associated with reduced risk of CRC (P = 7E-05). The multivariate-adjusted odds ratio of CRC with each copy of the T allele was 0.93 (95% CI 0.89-0.96). The association of the SNP with risk of CRC differed according to mucinous histological features (P heterogeneity = 0.008). In addition, the (T) allele was associated with lower risk of tumors with Crohn's-like reaction but not tumors without such immune infiltrate (P heterogeneity = 0.02) and microsatellite instability-high (MSI-high) but not microsatellite stable or MSI-low tumors (P heterogeneity = 0.03). The minor allele (T) in SNP rs11676348, located downstream from CXCR2 that has been implicated in CRC progression, is associated with a lower risk of CRC, particularly tumors with a mucinous component, Crohn's-like reaction and MSI-high. Our findings offer the promise of risk stratification of inflammatory bowel disease patients for complications such as CRC.

Anthropometry and head and neck cancer:a pooled analysis of cohort data

BACKGROUND

Associations between anthropometry and head and neck cancer (HNC) risk are inconsistent. We aimed to evaluate these associations while minimizing biases found in previous studies.

METHODS

We pooled data from 1,941,300 participants, including 3760 cases, in 20 cohort studies and used multivariable-adjusted Cox proportional hazard regression models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association of anthropometric measures with HNC risk overall and stratified by smoking status.

RESULTS

Greater waist circumference (per 5 cm: HR = 1.04, 95% CI 1.03-1.05, P-value for trend = <0.0001) and waist-to-hip ratio (per 0.1 unit: HR = 1.07, 95% CI 1.05-1.09, P-value for trend = <0.0001), adjusted for body mass index (BMI), were associated with higher risk and did not vary by smoking status (P-value for heterogeneity = 0.85 and 0.44, respectively). Associations with BMI (P-value for interaction = <0.0001) varied by smoking status. Larger BMI was associated with higher HNC risk in never smokers (per 5 kg/m(2): HR = 1.15, 95% CI 1.06-1.24, P-value for trend = 0.0006), but not in former smokers (per 5 kg/m(2): HR = 0.99, 95% CI 0.93-1.06, P-value for trend = 0.79) or current smokers (per 5 kg/m(2): HR = 0.76, 95% CI 0.71-0.82, P-value for trend = <0.0001). Larger hip circumference was not associated with a higher HNC risk. Greater height (per 5 cm) was associated with higher risk of HNC in never and former smokers, but not in current smokers.

CONCLUSIONS

Waist circumference and waist-to-hip ratio were associated positively with HNC risk regardless of smoking status, whereas a positive association with BMI was only found in never smokers.

A model to determine colorectal cancer risk using common genetic susceptibility loci

BACKGROUND & AIMS

Risk for colorectal cancer (CRC) can be greatly reduced through screening. To aid in the development of screening strategies, we refined models designed to determine risk of CRC by incorporating information from common genetic susceptibility loci.

METHODS

By using data collected from more than 12,000 participants in 6 studies performed from 1990 through 2011 in the United States and Germany, we developed risk determination models based on sex, age, family history, genetic risk score (number of risk alleles carried at 27 validated common CRC susceptibility loci), and history of endoscopic examinations. The model was validated using data collected from approximately 1800 participants in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, conducted from 1993 through 2001 in the United States.

RESULTS

We identified a CRC genetic risk score that independently predicted which patients in the training set would develop CRC. Compared with determination of risk based only on family history, adding the genetic risk score increased the discriminatory accuracy from 0.51 to 0.59 (P = .0028) for men and from 0.52 to 0.56 (P = .14) for women. We calculated age- and sex-specific 10-year CRC absolute risk estimates based on the number of risk alleles, family history, and history of endoscopic examinations. A model that included a genetic risk score better determined the recommended starting age for screening in subjects with and without family histories of CRC. The starting age for high-risk men (family history of CRC and genetic risk score, 90%) was 42 years, and for low-risk men (no family history of CRC and genetic risk score, 10%) was 52 years. For men with no family history and a high genetic risk score (90%), the starting age would be 47 years; this is an intermediate value that is 5 years earlier than it would be for men with a genetic risk score of 10%. Similar trends were observed in women.

CONCLUSIONS

By incorporating information on CRC risk alleles, we created a model to determine the risk for CRC more accurately. This model might be used to develop screening and prevention strategies.

Mendelian randomization study of height and risk of colorectal cancer

BACKGROUND

For men and women, taller height is associated with increased risk of all cancers combined. For colorectal cancer (CRC), it is unclear whether the differential association of height by sex is real or is due to confounding or bias inherent in observational studies. We performed a Mendelian randomization study to examine the association between height and CRC risk.

METHODS

To minimize confounding and bias, we derived a weighted genetic risk score predicting height (using 696 genetic variants associated with height) in 10,226 CRC cases and 10,286 controls. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for associations between height, genetically predicted height and CRC.

RESULTS

Using conventional methods, increased height (per 10-cm increment) was associated with increased CRC risk (OR = 1.08, 95% CI = 1.02-1.15). In sex-specific analyses, height was associated with CRC risk for women (OR = 1.15, 95% CI = 1.05-1.26), but not men (OR = 0.98, 95% CI = 0.92-1.05). Consistent with these results, carrying greater numbers of (weighted) height-increasing alleles (per 1-unit increase) was associated with higher CRC risk for women and men combined (OR = 1.07, 95% CI = 1.01-1.14) and for women (OR = 1.09, 95% CI =  .01-1.19). There was weaker evidence of an association for men (OR = 1.05, 95% CI = 0.96-1.15).

CONCLUSION

We provide evidence for a causal association between height and CRC for women. The CRC-height association for men remains unclear and warrants further investigation in other large studies.

Further Confirmation of Germline Glioma Risk Variant rs78378222 in TP53 and Its Implication in Tumor Tissues via Integrative Analysis of TCGA Data

We confirmed strong association of rs78378222:A>C (per allele odds ratio [OR] = 3.14; P = 6.48 × 10(-11) ), a germline rare single-nucleotide polymorphism (SNP) in TP53, via imputation of a genome-wide association study of glioma (1,856 cases and 4,955 controls). We subsequently performed integrative analyses on the Cancer Genome Atlas (TCGA) data for GBM (glioblastoma multiforme) and LUAD (lung adenocarcinoma). Based on SNP data, we imputed genotypes for rs78378222 and selected individuals carrying rare risk allele (C). Using RNA sequencing data, we observed aberrant transcripts with ∼3 kb longer than normal for those individuals. Using exome sequencing data, we further showed that loss of haplotype carrying common protective allele (A) occurred somatically in GBM but not in LUAD. Our bioinformatic analysis suggests rare risk allele (C) disrupts mRNA termination, and an allelic loss of a genomic region harboring common protective allele (A) occurs during tumor initiation or progression for glioma.

Mendelian Randomization Study of Body Mass Index and Colorectal Cancer Risk

BACKGROUND

High body mass index (BMI) is consistently linked to increased risk of colorectal cancer for men, whereas the association is less clear for women. As risk estimates from observational studies may be biased and/or confounded, we conducted a Mendelian randomization study to estimate the causal association between BMI and colorectal cancer.

METHODS

We used data from 10,226 colorectal cancer cases and 10,286 controls of European ancestry. The Mendelian randomization analysis used a weighted genetic risk score, derived from 77 genome-wide association study-identified variants associated with higher BMI, as an instrumental variable (IV). We compared the IV odds ratio (IV-OR) with the OR obtained using a conventional covariate-adjusted analysis.

RESULTS

Individuals carrying greater numbers of BMI-increasing alleles had higher colorectal cancer risk [per weighted allele OR, 1.31; 95% confidence interval (CI), 1.10-1.57]. Our IV estimation results support the hypothesis that genetically influenced BMI is directly associated with risk for colorectal cancer (IV-OR per 5 kg/m(2), 1.50; 95% CI, 1.13-2.01). In the sex-specific IV analyses higher BMI was associated with higher risk of colorectal cancer among women (IV-OR per 5 kg/m(2), 1.82; 95% CI, 1.26-2.61). For men, genetically influenced BMI was not associated with colorectal cancer (IV-OR per 5 kg/m(2), 1.18; 95% CI, 0.73-1.92).

CONCLUSIONS

High BMI was associated with increased colorectal cancer risk for women. Whether abdominal obesity, rather than overall obesity, is a more important risk factor for men requires further investigation.

IMPACT

Overall, conventional epidemiologic and Mendelian randomization studies suggest a strong association between obesity and the risk of colorectal cancer.

Long-chain ω-3 fatty acid intake and endometrial cancer risk in the Women's Health Initiative

BACKGROUND

Inflammation may be important in endometrial cancer development. Long-chain ω-3 (n-3) polyunsaturated fatty acids (LCω-3PUFAs) may reduce inflammation and, therefore, reduce cancer risk. Because body mass is associated with both inflammation and endometrial cancer risk, it may modify the association of fat intake on risk.

OBJECTIVE

We examined whether intakes of LCω-3PUFAs were associated with endometrial cancer risk overall and stratified by body size and histologic subtype.

DESIGN

Women were n = 87,360 participants of the Women's Health Initiative Observational Study and Clinical Trials who were aged 50-79 y, had an intact uterus, and completed a baseline food-frequency questionnaire. After 13 y of follow-up, n = 1253 incident invasive endometrial cancers were identified. Cox regression models were used to estimate HRs and 95% CIs for the association of intakes of individual ω-3 fatty acids and fish with endometrial cancer risk.

RESULTS

Intakes of individual LCω-3PUFAs were associated with 15-23% linear reductions in endometrial cancer risk. In women with body mass index (BMI; in kg/m(2)) <25, those in the upper compared with lowest quintiles of total LCω-3PUFA intake (sum of eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) had significantly reduced endometrial cancer risk (HR: 0.59; 95% CI: 0.40, 0.82; P-trend = 0.001), whereas there was little evidence of an association in overweight or obese women. The reduction in risk observed in normal-weight women was further specific to type I cancers.

CONCLUSIONS

Long-chain ω-3 intake was associated with reduced endometrial cancer risk only in normal-weight women. Additional studies that use biomarkers of ω-3 intake are needed to more accurately estimate their effects on endometrial cancer risk. This trial was registered at clinicaltrials.gov as NCT00000611.

Vitamin D metabolic pathway genes and pancreatic cancer risk

Evidence on the association between vitamin D status and pancreatic cancer risk is inconsistent. This inconsistency may be partially attributable to variation in vitamin D regulating genes. We selected 11 vitamin D-related genes (GC, DHCR7, CYP2R1, VDR, CYP27B1, CYP24A1, CYP27A1, RXRA, CRP2, CASR and CUBN) totaling 213 single nucleotide polymorphisms (SNPs), and examined associations with pancreatic adenocarcinoma. Our study included 3,583 pancreatic cancer cases and 7,053 controls from the genome-wide association studies of pancreatic cancer PanScans-I-III. We used the Adaptive Joint Test and the Adaptive Rank Truncated Product statistic for pathway and gene analyses, and unconditional logistic regression for SNP analyses, adjusting for age, sex, study and population stratification. We examined effect modification by circulating vitamin D concentration (≤50, >50 nmol/L) for the most significant SNPs using a subset of cohort cases (n = 713) and controls (n = 878). The vitamin D metabolic pathway was not associated with pancreatic cancer risk (p = 0.830). Of the individual genes, none were associated with pancreatic cancer risk at a significance level of p<0.05. SNPs near the VDR (rs2239186), LRP2 (rs4668123), CYP24A1 (rs2762932), GC (rs2282679), and CUBN (rs1810205) genes were the top SNPs associated with pancreatic cancer (p-values 0.008-0.037), but none were statistically significant after adjusting for multiple comparisons. Associations between these SNPs and pancreatic cancer were not modified by circulating concentrations of vitamin D. These findings do not support an association between vitamin D-related genes and pancreatic cancer risk. Future research should explore other pathways through which vitamin D status might be associated with pancreatic cancer risk.

Association of aspirin and NSAID use with risk of colorectal cancer according to genetic variants

IMPORTANCE

Use of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with lower risk of colorectal cancer.

OBJECTIVE

To identify common genetic markers that may confer differential benefit from aspirin or NSAID chemoprevention, we tested gene × environment interactions between regular use of aspirin and/or NSAIDs and single-nucleotide polymorphisms (SNPs) in relation to risk of colorectal cancer.

DESIGN, SETTING, AND PARTICIPANTS

Case-control study using data from 5 case-control and 5 cohort studies initiated between 1976 and 2003 across the United States, Canada, Australia, and Germany and including colorectal cancer cases (n=8634) and matched controls (n=8553) ascertained between 1976 and 2011. Participants were all of European descent.

EXPOSURES

Genome-wide SNP data and information on regular use of aspirin and/or NSAIDs and other risk factors.

MAIN OUTCOMES AND MEASURES

Colorectal cancer.

RESULTS

Regular use of aspirin and/or NSAIDs was associated with lower risk of colorectal cancer (prevalence, 28% vs 38%; odds ratio [OR], 0.69 [95% CI, 0.64-0.74]; P = 6.2 × 10(-28)) compared with nonregular use. In the conventional logistic regression analysis, the SNP rs2965667 at chromosome 12p12.3 near the MGST1 gene showed a genome-wide significant interaction with aspirin and/or NSAID use (P = 4.6 × 10(-9) for interaction). Aspirin and/or NSAID use was associated with a lower risk of colorectal cancer among individuals with rs2965667-TT genotype (prevalence, 28% vs 38%; OR, 0.66 [95% CI, 0.61-0.70]; P = 7.7 × 10(-33)) but with a higher risk among those with rare (4%) TA or AA genotypes (prevalence, 35% vs 29%; OR, 1.89 [95% CI, 1.27-2.81]; P = .002). In case-only interaction analysis, the SNP rs16973225 at chromosome 15q25.2 near the IL16 gene showed a genome-wide significant interaction with use of aspirin and/or NSAIDs (P = 8.2 × 10(-9) for interaction). Regular use was associated with a lower risk of colorectal cancer among individuals with rs16973225-AA genotype (prevalence, 28% vs 38%; OR, 0.66 [95% CI, 0.62-0.71]; P = 1.9 × 10(-30)) but was not associated with risk of colorectal cancer among those with less common (9%) AC or CC genotypes (prevalence, 36% vs 39%; OR, 0.97 [95% CI, 0.78-1.20]; P = .76).

CONCLUSIONS AND RELEVANCE

In this genome-wide investigation of gene × environment interactions, use of aspirin and/or NSAIDs was associated with lower risk of colorectal cancer, and this association differed according to genetic variation at 2 SNPs at chromosomes 12 and 15. Validation of these findings in additional populations may facilitate targeted colorectal cancer prevention strategies.

Characterization of large structural genetic mosaicism in human autosomes

Analyses of genome-wide association study (GWAS) data have revealed that detectable genetic mosaicism involving large (>2 Mb) structural autosomal alterations occurs in a fraction of individuals. We present results for a set of 24,849 genotyped individuals (total GWAS set II [TGSII]) in whom 341 large autosomal abnormalities were observed in 168 (0.68%) individuals. Merging data from the new TGSII set with data from two prior reports (the Gene-Environment Association Studies and the total GWAS set I) generated a large dataset of 127,179 individuals; we then conducted a meta-analysis to investigate the patterns of detectable autosomal mosaicism (n = 1,315 events in 925 [0.73%] individuals). Restricting to events >2 Mb in size, we observed an increase in event frequency as event size decreased. The combined results underscore that the rate of detectable mosaicism increases with age (p value = 5.5 × 10(-31)) and is higher in men (p value = 0.002) but lower in participants of African ancestry (p value = 0.003). In a subset of 47 individuals from whom serial samples were collected up to 6 years apart, complex changes were noted over time and showed an overall increase in the proportion of mosaic cells as age increased. Our large combined sample allowed for a unique ability to characterize detectable genetic mosaicism involving large structural events and strengthens the emerging evidence of non-random erosion of the genome in the aging population.

Male pattern baldness in relation to prostate cancer risks: an analysis in the VITamins and lifestyle (VITAL) cohort study

BACKGROUND

Male pattern baldness and prostate cancer may share common pathophysiological mechanisms in terms of advancing age, heritability, and endogenous hormones. Results from previous epidemiologic studies are inconsistent. Therefore, we investigated the association of prostate cancer risks with male pattern baldness at age 30 years, age 45 years, and baseline (median age = 60.5 years) in the VITamins And Lifestyle (VITAL) cohort study.

METHODS

We included 32,583 men who were aged 50-76 years and without prior cancer diagnosis (excluding non-melanoma skin cancer) at the start of follow-up. First primary incident prostate cancers were ascertained via linkage to the western Washington Surveillance, Epidemiology, and End Results (SEER) program. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated using Cox proportional hazards regressions with adjustment for potential confounders.

RESULTS

During follow-up (median = 9 years), 2,306 incident prostate cancers were diagnosed. Male pattern baldness at age 30 years, age 45 years, and baseline were not statistically significantly associated with overall or subtypes of prostate cancer.

CONCLUSION

This study did not provide support for the hypothesis that male pattern baldness may be a marker for subsequent prostate cancer. Previous evidence indicates that a distinct class of frontal with vertex balding may be associated with increased risk of aggressive prostate cancer, but all such balding classes were captured as a single exposure category by the VITAL cohort questionnaire. Prostate 75:415-423, 2015. © 2014 Wiley Periodicals, Inc.

Randomized trial of glucosamine and chondroitin supplementation on inflammation and oxidative stress biomarkers and plasma proteomics profiles in healthy humans

BACKGROUND

Glucosamine and chondroitin are popular non-vitamin dietary supplements used for osteoarthritis. Long-term use is associated with lower incidence of colorectal and lung cancers and with lower mortality; however, the mechanism underlying these observations is unknown. In vitro and animal studies show that glucosamine and chondroitin inhibit NF-kB, a central mediator of inflammation, but no definitive trials have been done in healthy humans.

METHODS

We conducted a randomized, double-blind, placebo-controlled, cross-over study to assess the effects of glucosamine hydrochloride (1500 mg/d) plus chondroitin sulfate (1200 mg/d) for 28 days compared to placebo in 18 (9 men, 9 women) healthy, overweight (body mass index 25.0-32.5 kg/m2) adults, aged 20-55 y. We examined 4 serum inflammatory biomarkers: C-reactive protein (CRP), interleukin 6, and soluble tumor necrosis factor receptors I and II; a urinary inflammation biomarker: prostaglandin E2-metabolite; and a urinary oxidative stress biomarker: F2-isoprostane. Plasma proteomics on an antibody array was performed to explore other pathways modulated by glucosamine and chondroitin.

RESULTS

Serum CRP concentrations were 23% lower after glucosamine and chondroitin compared to placebo (P = 0.048). There were no significant differences in other biomarkers. In the proteomics analyses, several pathways were significantly different between the interventions after Bonferroni correction, the most significant being a reduction in the "cytokine activity" pathway (P = 2.6 x 10-16), after glucosamine and chondroitin compared to placebo.

CONCLUSION

Glucosamine and chondroitin supplementation may lower systemic inflammation and alter other pathways in healthy, overweight individuals. This study adds evidence for potential mechanisms supporting epidemiologic findings that glucosamine and chondroitin are associated with reduced risk of lung and colorectal cancer.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01682694.

Association of Nonsteroidal Anti-Inflammatory Drugs with Colorectal Cancer by Subgroups in the VITamins and Lifestyle (VITAL) Study

BACKGROUND

There is substantial evidence that use of NSAIDs reduces the risk of colorectal cancer, but no subgroup has been identified for which the chemoprevention effect outweighs the risk of side effects.

METHODS

We tested the interaction between NSAID use and multiple risk factors on colorectal cancer risk in the VITAL cohort. A total of 73,458 individuals ages 50 to 76 years completed a questionnaire between 2000 and 2002, and 674 incidental colorectal cancer cases were identified through 2010.

RESULTS

In stratified analysis, high use of any type of NSAIDs (4+ days/week for 4+ years) was statistically significantly associated with a lower risk of colorectal cancer across all subgroups stratified by sex, body mass index, physical activity, smoking, alcohol intake, screening, and dietary factors. There was a suggestion of stronger associations among men, obese individuals, and heavier drinkers; however, none of these tests for interaction reached statistical significance. The associations were almost identical for subjects with higher overall colorectal cancer risk scores [HR, 0.62; 95% confidence interval (CI), 0.49-0.79] and those with lower risk scores (HR, 0.61; 95% CI, 0.42-0.88). Differential effects by cancer subsites and stages were tested. NSAID use was associated with a greater risk reduction of proximal colon cancer versus distal (P for difference = 0.06) and distant stage versus local (P for difference = 0.04).

CONCLUSION

The association between high use of NSAIDs and colorectal cancer risk does not differ significantly among subgroups.

IMPACT

Our results suggest that NSAIDs have a generally beneficial role in colorectal cancer prevention, largely unmodified by other exposures.

Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33

Genome-wide association studies (GWAS) have mapped risk alleles for at least 10 distinct cancers to a small region of 63 000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (association analysis based on subsets) across six distinct cancers in 34 248 cases and 45 036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single-nucleotide polymorphisms: five in the TERT gene (Region 1: rs7726159, P = 2.10 × 10(-39); Region 3: rs2853677, P = 3.30 × 10(-36) and PConditional = 2.36 × 10(-8); Region 4: rs2736098, P = 3.87 × 10(-12) and PConditional = 5.19 × 10(-6), Region 5: rs13172201, P = 0.041 and PConditional = 2.04 × 10(-6); and Region 6: rs10069690, P = 7.49 × 10(-15) and PConditional = 5.35 × 10(-7)) and one in the neighboring CLPTM1L gene (Region 2: rs451360; P = 1.90 × 10(-18) and PConditional = 7.06 × 10(-16)). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele-specific effects on DNA methylation were seen for a subset of risk loci, indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci.

Genetic variants of adiponectin and risk of colorectal cancer

Circulating adiponectin has been associated with lower risk of colorectal cancer (CRC). Genome-wide association studies have identified several single-nucleotide polymorphisms (SNPs) associated with adiponectin levels. However, it is unclear whether these SNPs are associated with CRC risk. In addition, previous data on SNPs in the adiponectin pathway and their associations with CRC are inconsistent. Therefore, we examined 19 SNPs in genes related to adiponectin or its receptors and their associations with CRC using logistic regression among 7,020 cases and 7,631 controls drawn from ten studies included in the Genetics and Epidemiology of Colorectal Cancer Consortium. Using data from a subset of two large cohort studies, we also assessed the contribution of individual SNPs and an adiponectin genetic score to plasma adiponectin after accounting for lifestyle factors among 2,217 women and 619 men. We did not find any statistically significant association between the 19 adiponectin-associated SNPs and CRC risk (multivariable-adjusted odds ratios ranged from 0.89 to 1.05, all p > 0.05). Each SNP explained less than 2.50% of the variance of plasma adiponectin, and the genetic score collectively accounted for 2.95 and 1.42% of the variability of adiponectin in women and men, respectively, after adjustment for age, body mass index, physical activity, smoking, alcohol consumption, regular use of aspirin or nonsteroidal anti-inflammatory drug and postmenopausal hormone use. In conclusion, our findings do not support an association between known adiponectin-related common SNPs and CRC incidence. However, known common SNPs account for only a limited proportion of the interindividual variance in circulating adiponectin. Further work is warranted to investigate the relationship between adiponectin and CRC while accounting for other components in the pathway.

Red meat intake, NAT2, and risk of colorectal cancer: a pooled analysis of 11 studies

BACKGROUND

Red meat intake has been associated with risk of colorectal cancer, potentially mediated through heterocyclic amines. The metabolic efficiency of N-acetyltransferase 2 (NAT2) required for the metabolic activation of such amines is influenced by genetic variation. The interaction between red meat intake, NAT2 genotype, and colorectal cancer has been inconsistently reported.

METHODS

We used pooled individual-level data from the Colon Cancer Family Registry and the Genetics and Epidemiology of Colorectal Cancer Consortium. Red meat intake was collected by each study. We inferred NAT2 phenotype based on polymorphism at rs1495741, highly predictive of enzyme activity. Interaction was assessed using multiplicative interaction terms in multivariate-adjusted models.

RESULTS

From 11 studies, 8,290 colorectal cancer cases and 9,115 controls were included. The highest quartile of red meat intake was associated with increased risk of colorectal cancer compared with the lowest quartile [OR, 1.41; 95% confidence interval (CI), 1.29-1.55]. However, a significant association was observed only for studies with retrospective diet data, not for studies with diet prospectively assessed before cancer diagnosis. Combining all studies, high red meat intake was similarly associated with colorectal cancer in those with a rapid/intermediate NAT2 genotype (OR, 1.38; 95% CI, 1.20-1.59) as with a slow genotype (OR, 1.43; 95% CI, 1.28-1.61; P interaction = 0.9).

CONCLUSION

We found that high red meat intake was associated with increased risk of colorectal cancer only from retrospective case-control studies and not modified by NAT2 enzyme activity.

IMPACT

Our results suggest no interaction between NAT2 genotype and red meat intake in mediating risk of colorectal cancer.