A prospective cohort study of dietary indices and incidence of epithelial ovarian cancer

BACKGROUND

Several dietary indices have been developed to measure overall diet quality, including the Healthy Eating Index-2005 (HEI-2005), which measures adherence to the 2005 Dietary Guidelines from the USDA; the Alternative Healthy Eating Index-2010 (AHEI-2010), which is based on foods and nutrients predictive of chronic disease risk; and the Alternate Mediterranean Diet Score (aMDS), which is an index that characterizes traditional food patterns of Mediterranean countries. Few studies have evaluated diet quality and ovarian cancer risk.

METHODS

We assessed the associations of the HEI-2005, AHEI-2010, and aMDS with risk of epithelial ovarian cancer prospectively among women in the Nurses' Health Study. We used Cox proportional hazards models, adjusting for known ovarian cancer risk factors.

RESULTS

During 24 years of follow-up, we documented 696 incident epithelial ovarian cancer cases among 82,948 women with diet information. The multivariate adjusted hazard ratios (95% confidence interval; Ptrend) of epithelial ovarian cancer comparing the highest with the lowest quintile were 1.03 (0.80-1.34; 0.77) for the AHEI-2010, 0.85 (0.65-1.12; 0.57) for the HEI-2005, and 0.91 (0.71-1.18; 0.44) for the aMDS.

CONCLUSIONS

We did not observe any clear association of three diet quality scores with ovarian cancer risk. Further work should other metrics of evaluating diet quality that may be more relevant cancer risk.

Abstract 2197: Interaction between genetic variants in one-carbon metabolism and folate biomarkers on colorectal cancer risk: The Women's Health Initiative observational cohort

Folate-mediated one-carbon metabolism (FOCM) is important in the development of colorectal cancer (CRC), but gene-nutrient interactions in this relationship have not been comprehensively evaluated. We investigated whether folate modified the association of genetic variants of FOCM with CRC risk. Among 821 Caucasian case/control matched pairs in the Women's Health Initiative observational cohort (1993-2008), we genotyped 453 single nucleotide polymorphisms (SNPs) tagging 227 independent loci in 30 genes in FOCM pathways (AARS, ADH1B, ADH1C, BHMT, BHMT2, CBS, DHFR, DNMT1, DNMT3A, DNMT3B, EHMT1, EHMT2, FOLH1, FOLR1, GGH, GNMT, MAT1A, MAT2B, MTHFD1, MTHFD2, MTHFR, MTR, MTRR, PON1, PRDM2, SHMT1, SHMT2, SLC19A1, TCN2, and TYMS). Folate concentrations in plasma and red blood cell (RBC) were measured by radioassays. Multivariable conditional logistic regression was used to estimate odds ratios, and likelihood ratio tests were performed to test the differences in the associations of SNPs with CRC among plasma/RBC folate tertile categories. Nominal P-values were reported for non-synonymous and candidate SNPs. For tagSNPs, we used the Benjamini and Hochberg method to control false discovery rate (FDR) at the gene level. When comparing homozygous variants with wild-types, we observed higher risks of CRC associated with genetic variants in folate absorption and uptake in the presence of low (tertile 1) plasma folate concentrations: GGH (rs16930073, flanking 3′UTR, P-interaction=0.006), FOLH1 (rs10839236, intron, candidate, P=0.018; rs2299650, intron, P=0.016), and FOLR1 (rs651646, intron, P=0.021). In other FOCM pathways (methionine/S-adenosylmethionine reactions, vitamin B12 transport, and DNA methylation), plasma/RBC folate also modified important non-synonymous and candidate SNPs in relation to CRC risk: MTRR (C524T [p.S202L], P=0.045), CBS (rs1801181 [p.A360A], P=0.035), TCN2 (C776G [p.R232P], P=0.040), DNMT1 (A201G [p.I311L], P=0.016), DNMT3A (rs11695471 [intron 22 A>T], candidate, P=0.002), and DNMT3B (283T>C, 5′ near gene, p=0.043). In addition, interactions with plasma/RBC folate were observed for several variants in paraoxonase 1 (PON1), an enzyme generating homocysteine from homocysteine thiolactone: p.L55M (P=0.021), rs8491 (3′UTR, P=0.037), rs854548 (3′ near gene, P=0.033), rs854551 (3′UTR, P=0.045), and rs3917527 (intron, P=0.006). All significant interactions with tagSNPs remained as “noteworthy” at the FDR 25% level. In conclusion, our observations highlight the importance of folate status when investigating FOCM-related genetic influences on CRC risk in postmenopausal women.

Citation Format: Ting-Yuan D. Cheng, Karen W. Makar, Marian L. Neuhouser, Joshua W. Miller, Xiaoling Song, Elissa C. Brown, Shirley A.A. Beresford, Yingye Zheng, David J. Duggan, Elizabeth M. Poole, Nina Habermann, Reka Toth, Lynn B. Bailey, Marie A. Caudill, Cornelia M. Ulrich. Interaction between genetic variants in one-carbon metabolism and folate biomarkers on colorectal cancer risk: The Women's Health Initiative observational cohort. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2197. doi:10.1158/1538-7445.AM2014-2197

Consortium analysis of gene and gene-folate interactions in purine and pyrimidine metabolism pathways with ovarian carcinoma risk

SCOPE

We reevaluated previously reported associations between variants in pathways of one-carbon (1-C) (folate) transfer genes and ovarian carcinoma (OC) risk, and in related pathways of purine and pyrimidine metabolism, and assessed interactions with folate intake.

METHODS AND RESULTS

Odds ratios (OR) for 446 genetic variants were estimated among 13,410 OC cases and 22,635 controls, and among 2281 cases and 3444 controls with folate information. Following multiple testing correction, the most significant main effect associations were for dihydropyrimidine dehydrogenase (DPYD) variants rs11587873 (OR = 0.92; p = 6 × 10⁻⁵) and rs828054 (OR = 1.06; p = 1 × 10⁻⁴). Thirteen variants in the pyrimidine metabolism genes, DPYD, DPYS, PPAT, and TYMS, also interacted significantly with folate in a multivariant analysis (corrected p = 9.9 × 10⁻⁶) but collectively explained only 0.2% of OC risk. Although no other associations were significant after multiple testing correction, variants in SHMT1 in 1-C transfer, previously reported with OC, suggested lower risk at higher folate (p(interaction) = 0.03-0.006).

CONCLUSION

Variation in pyrimidine metabolism genes, particularly DPYD, which was previously reported to be associated with OC, may influence risk; however, stratification by folate intake is unlikely to modify disease risk appreciably in these women. SHMT1 SNP-by-folate interactions are plausible but require further validation. Polymorphisms in selected genes in purine metabolism were not associated with OC.

Abstract 4124: Ovarian cancer survival by tumor subtype

Introduction: Epithelial ovarian cancer is heterogeneous, with subgroups defined by cell of origin (ovary vs. fallopian tube), histology, and carcinogenic pathway (the etiologic pathway through which tumors arise: type I tumors develop on the ovarian surface and are low grade serous or mucinous histology; type II tumors develop through endometriotic implantation and are clear cell or endometrioid histology; type III tumors originate in the fallopian tube and are high grade serous histology). Although differences in associations have been observed with risk of incident ovarian cancer, few studies have examined differences in survival by subtype. In the New England Case-Control Study of ovarian cancer (NECC), we examined differences in survival by tumor dominance (a surrogate for cell of origin), histology, and carcinogenic pathway.

Methods: Among 2076 women with epithelial ovarian cancer (1991-2008), 892 deaths were observed. Cox proportional hazards regression was used to calculate hazards ratios (HRs) and 95% confidence intervals (95% CI) for the association of ovarian cancer subtype with overall survival, adjusting for age at diagnosis, study phase, year of diagnosis (as a proxy for treatment), BMI, and smoking status.

Results: Serous invasive tumors were more likely to be non-dominant (likely fallopian origin) and type III. Compared to serous invasive tumors, all other tumor histologies had statistically significantly improved survival. Similarly, dominant tumors (i.e., likely ovarian origin) had greater survival than non-dominant tumors (HR: 0.38; 95% CI: 0.31-0.47). Type I (mucinous and low grade serous) and type II (endometrioid and clear cell) tumors had better survival than type III (high grade serous) tumors (HR: 0.21; 95%CI: 0.16-0.28 and HR: 0.23; 95% CI: 0.18-0.29, respectively).

Conclusion: Regardless of how subtype was defined, high grade, invasive serous tumors had worse survival compared to other tumor subtypes. This underscores the need for prevention and treatment targeted at these aggressive tumors.

Table.Associations between tumor subtype and overall survivalSubtypeDeaths/CasesMedian Survival (years)HR (95% CI)HistologySerous invasive654/9683.21.00 (ref.)Serous borderline25/25010.10.35 (0.18-0.67)Mucinous36/2427.10.38 (0.25-0.58)Endometrioid68/3314.70.28 (0.21-0.37)Clear cell29/1163.40.30 (0.21-0.44)DominanceNon-dominant268/3853.31.00 (ref.)Dominant162/6034.00.38 (0.31-0.47)PathwayType III596/8563.21.00 (ref.)Type II97/4474.00.23 (0.18-0.29)Type I60/2915.70.21 (0.16-0.28)

Citation Format: Elizabeth M. Poole, Daniel W. Cramer, Allison F. Vitonis, Kathryn L. Terry. Ovarian cancer survival by tumor subtype. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4124. doi:10.1158/1538-7445.AM2014-4124

Abstract 2182: Lifestyle factors are associated with late breast cancer outcomes among 5-year survivors of estrogen-receptor positive breast cancer

Background: Estrogen-receptor (ER)+ breast cancers have a favorable prognosis in the first several years after diagnosis, with adjuvant endocrine therapies for treatment. However, in later years, ER+ breast cancer is associated with poorer prognosis compared to ER- breast cancer. Predictors of late recurrence in women with ER+ breast cancer, and in particular lifestyle factors, have been little studied. Using data from a pooling project of breast cancer survivor cohorts (After Breast Cancer Pooling Project), we prospectively evaluated the association of post-diagnosis lifestyle factors and comorbidities with late breast cancer outcomes.

Methods: Analyses included 6,129 women diagnosed with stage I-III invasive ER+ breast cancer (1990-2004) from three US prospective cohorts, who survived disease-free for five years. Pooled and harmonized data were available for post-diagnosis lifestyle factors, comorbidities, cancer treatment, tumor characteristics, and socio-demographics. Late outcomes (defined as >5 years post-diagnosis) included breast cancer recurrence, breast cancer specific-mortality (BCSM), and all-cause mortality. Lifestyle factors and comorbidities were assessed at a mean of about 2 years post-diagnosis. Study heterogeneity was evaluated by the Q statistic. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression models stratified by study.

Results: After a median follow-up of 6.9 years (11.9 years post-diagnosis), 645 deaths and 564 recurrences were documented. Five-year recurrence and all-cause mortality rates were 7.2% and 6.1%, respectively. Ten-year recurrence and all-causes mortality rates were 12.1% and 15.4%, respectively. In multivariable models, recreational physical activity (PA) of 10-MET h/wk was associated with reduced all-cause mortality (HR: 0.71, 95% CI: 0.60-0.84) and BCSM (HR: 0.77, 95% CI: 0.61-0.99), and non-significantly reduced recurrence risk (HR: 0.87, 95% CI: 0.73-1.03). Multivitamin and antioxidant vitamin supplement use were inversely associated with recurrence (HRs (95% CIs): 0.74 (0.62-0.87) and 0.75 (0.61-0.91), respectively). Current smoking was associated with increased risk of all-cause and BCSM ((HRs (95% CIs): 2.58 (1.99-3.35)) and 1.87 (1.22-2.88), respectively). Women with diabetes had increased risk of late outcomes (HRs 95% CIs: 1.35 (0.95-1.92) for recurrence, 1.86 (1.45-2.40) for all-cause mortality, and 1.75 (1.12-2.73) for BCSM. Hypertension was significantly associated with all-cause mortality only (HR: 1.42, 95% CI: 1.19-1.70). Obesity (BMI ≥30 kg/m2) was not associated with late outcomes.

Conclusion: In this large study, post-diagnosis lifestyle factors were important predictors of late breast cancer outcomes. Our findings suggest PA and multivitamin use may improve long-term prognosis for ER-positive breast cancer.

Citation Format: Sarah J. Nechuta, Wendy Y. Chen, Marilyn L. Kwan, Elizabeth M. Poole, Shirley W. Flatt, John P. Pierce, Bette J. Caan, Xiao Ou Shu. Lifestyle factors are associated with late breast cancer outcomes among 5-year survivors of estrogen-receptor positive breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2182. doi:10.1158/1538-7445.AM2014-2182

COX-1 (PTGS1) and COX-2 (PTGS2) polymorphisms, NSAID interactions, and risk of colon and rectal cancers in two independent populations

PURPOSE

Nonsteroidal anti-inflammatory drugs (NSAIDs) target the prostaglandin H synthase enzymes, cyclooxygenase (COX)-1 and COX-2, and reduce colorectal cancer risk. Genetic variation in the genes encoding these enzymes may be associated with changes in colon and rectal cancer risk and in NSAID efficacy.

METHODS

We genotyped candidate polymorphisms and tag SNPs in PTGS1 (COX-1) and PTGS2 (COX-2) in a population-based case–control study (Diet, Activity and Lifestyle Study, DALS) of colon cancer (n = 1,470 cases/1,837 controls) and rectal cancer (n = 583/775), and independently among cases and controls from the Colon Cancer Family Registry (CCFR; colon n = 959/1,535, rectal n = 505/839).

RESULTS

In PTGS2, a functional polymorphism (-765G[C; rs20417) was associated with a twofold increased rectal cancer risk (p = 0.05) in the DALS. This association replicated with a significant nearly fivefold increased risk of rectal cancer in the CCFR study (ORCC vs. GG = 4.88; 95 % CI 1.54–15.45; ORGC vs. GG = 1.36; 95 %CI 0.95–1.94). Genotype–NSAID interactions were observed in the DALS for PTGS1 and rectal cancer risk and for PTGS2 and colon cancer risk, but were no longer significant after correcting for multiple comparisons and did not replicate in the CCFR. No significant associations between PTGS1 polymorphisms and colon or rectal cancer risk were observed.

Genetic variation in prostaglandin synthesis and related pathways, NSAID use and colorectal cancer risk in the Colon Cancer Family Registry

Although use of non-steroidal anti-inflammatory drugs (NSAIDs) generally decreases colorectal cancer (CRC) risk, inherited genetic variation in inflammatory pathways may alter their potential as preventive agents. We investigated whether variation in prostaglandin synthesis and related pathways influences CRC risk in the Colon Cancer Family Registry by examining associations between 192 single nucleotide polymorphisms (SNPs) and two variable nucleotide tandem repeats (VNTRs) within 17 candidate genes and CRC risk. We further assessed interactions between these polymorphisms and NSAID use on CRC risk. Using a case-unaffected-sibling-control design, this study included 1621 primary invasive CRC cases and 2592 sibling controls among Caucasian men and women aged 18-90. After adjustment for multiple comparisons, two intronic SNPs were associated with rectal cancer risk: rs11571364 in ALOX12 [OR(het/hzv) = 1.87, 95% confidence interval (CI) = 1.19-2.95, P = 0.03] and rs45525634 in PTGER2 (OR(het/hzv) = 0.49, 95% CI = 0.29-0.82, P = 0.03). Additionally, there was an interaction between NSAID use and the intronic SNP rs2920421 in ALOX12 on risk of CRC (P = 0.03); among those with heterozygous genotypes, risk was reduced for current NSAID users compared with never or former users (OR(het) = 0.60, 95% CI = 0.45-0.80), though not among those with homozygous wild-type or variant genotypes. The results of this study suggest that genetic variation in ALOX12 and PTGER2 may affect the risk of rectal cancer. In addition, this study suggests plausible interactions between NSAID use and variants in ALOX12 on CRC risk. These results may aid in the development of genetically targeted cancer prevention strategies with NSAIDs.

Genome-wide association study of subtype-specific epithelial ovarian cancer risk alleles using pooled DNA

Epithelial ovarian cancer (EOC) is a heterogeneous cancer with both genetic and environmental risk factors. Variants influencing the risk of developing the less-common EOC subtypes have not been fully investigated. We performed a genome-wide association study (GWAS) of EOC according to subtype by pooling genomic DNA from 545 cases and 398 controls of European descent, and testing for allelic associations. We evaluated for replication 188 variants from the GWAS [56 variants for mucinous, 55 for endometrioid and clear cell, 53 for low-malignant potential (LMP) serous, and 24 for invasive serous EOC], selected using pre-defined criteria. Genotypes from 13,188 cases and 23,164 controls of European descent were used to perform unconditional logistic regression under the log-additive genetic model; odds ratios (OR) and 95 % confidence intervals are reported. Nine variants tagging six loci were associated with subtype-specific EOC risk at P < 0.05, and had an OR that agreed in direction of effect with the GWAS results. Several of these variants are in or near genes with a biological rationale for conferring EOC risk, including ZFP36L1 and RAD51B for mucinous EOC (rs17106154, OR = 1.17, P = 0.029, n = 1,483 cases), GRB10 for endometrioid and clear cell EOC (rs2190503, P = 0.014, n = 2,903 cases), and C22orf26/BPIL2 for LMP serous EOC (rs9609538, OR = 0.86, P = 0.0043, n = 892 cases). In analyses that included the 75 GWAS samples, the association between rs9609538 (OR = 0.84, P = 0.0007) and LMP serous EOC risk remained statistically significant at P < 0.0012 adjusted for multiple testing. Replication in additional samples will be important to verify these results for the less-common EOC subtypes.

Aspirin, nonaspirin nonsteroidal anti-inflammatory drug, and acetaminophen use and risk of invasive epithelial ovarian cancer: a pooled analysis in the Ovarian Cancer Association Consortium

BACKGROUND

Regular aspirin use is associated with reduced risk of several malignancies. Epidemiologic studies analyzing aspirin, nonaspirin nonsteroidal anti-inflammatory drug (NSAID), and acetaminophen use and ovarian cancer risk have been inconclusive.

METHODS

We analyzed pooled data from 12 population-based case-control studies of ovarian cancer, including 7776 case patients and 11843 control subjects accrued between 1992 and 2007. Odds ratios (ORs) for associations of medication use with invasive epithelial ovarian cancer were estimated in individual studies using logistic regression and combined using random effects meta-analysis. Associations between frequency, dose, and duration of analgesic use and risk of ovarian cancer were also assessed. All statistical tests were two-sided.

RESULTS

Aspirin use was associated with a reduced risk of ovarian cancer (OR = 0.91; 95% confidence interval [CI] = 0.84 to 0.99). Results were similar but not statistically significant for nonaspirin NSAIDs, and there was no association with acetaminophen. In seven studies with frequency data, the reduced risk was strongest among daily aspirin users (OR = 0.80; 95% CI = 0.67 to 0.96). In three studies with dose information, the reduced risk was strongest among users of low dose (<100 mg) aspirin (OR = 0.66; 95% CI = 0.53 to 0.83), whereas for nonaspirin NSAIDs, the reduced risk was strongest for high dose (≥500 mg) usage (OR = 0.76; 95% CI = 0.64 to 0.91).

CONCLUSIONS

Aspirin use was associated with a reduced risk of ovarian cancer, especially among daily users of low-dose aspirin. These findings suggest that the same aspirin regimen proven to protect against cardiovascular events and several cancers could reduce the risk of ovarian cancer 20% to 34% depending on frequency and dose of use.

Genetic variation in UGT genes modify the associations of NSAIDs with risk of colorectal cancer: colon cancer family registry

The use of non-steroidal anti-inflammatory drugs (NSAIDs) is associated with reduced risk of colorectal neoplasia. Previous studies have reported that polymorphisms in NSAID-metabolizing enzymes central to NSAID metabolism including UDP-glucuronosyltransferases (UGT) and cytochrome P450 (CYP) 2C9 may modify this protective effect. We investigated whether 35 functionally relevant polymorphisms within CYP2C9 and UGT genes were associated with colorectal cancer risk or modified the protective effect of NSAIDs on colorectal cancer susceptibility, using 1,584 colorectal cancer cases and 2,516 unaffected sibling controls from the Colon Cancer Family Registry. A three-SNP genotype in UGT1A6 (G-A-A; Ala7-Thr181-Arg184) and the Asp85 variant in UGT2B15 increased the risk of colorectal cancer (OR 3.87; 95% CI 1.04-14.45 and OR 1.34; 95% CI 1.10-1.63, respectively). We observed interactions between UGT1A3 Thr78Thr (A>G) and NSAID use (P-interaction = 0.02), a three-SNP genotype within UGT2B4 and ibuprofen use (P-interaction = 0.0018), as well as UGT2B15 Tyr85Asp (T>G) and aspirin use (P-interaction = 0.01). The interaction with the UGT2B4 and the UGT2B15 polymorphisms were noteworthy at the 25% FDR level. This study highlights the need for further pharmacogenetic studies to identify individuals who might benefit from NSAID use as part of developing effective strategies for prevention of colorectal neoplasia. © 2014 Wiley Periodicals, Inc.

Lifetime cigarette smoking and breast cancer prognosis in the After Breast Cancer Pooling Project

BACKGROUND

There is controversy on whether former smokers have increased risk for breast cancer recurrence or all-cause mortality, regardless of how much they smoked.

METHODS

Data were from three US cohorts in the After Breast Cancer Pooling Project, with detailed information on smoking among 9975 breast cancer survivors. Smoking was assessed an average of 2 years after diagnosis. Delayed entry Cox proportional hazards models were used to examine the relationships of smoking status, cigarettes per day, years of smoking, and pack years with breast cancer prognosis. Endpoints included breast cancer recurrence (n = 1727), breast cancer mortality (n = 1059), and overall mortality (n = 1803).

RESULTS

Compared with never smokers, former smokers with less than 20 pack-years of exposure had no increased risk of any outcome. However, former smokers with 20 to less than 34.9 pack-years of exposure had a 22% increased risk of breast cancer recurrence (hazard ratio [HR] = 1.22; 95% confidence interval [CI] = 1.01 to 1.48) and a 26% increased risk of all-cause mortality (HR = 1.26; 95% CI = 1.07 to 1.48). For former smokers with 35 or more pack-years of exposure, the probability of recurrence increased by 37% (HR = 1.37; 95% CI = 1.13 to 1.66), breast cancer mortality increased by 54% (HR = 1.54; 95% CI = 1.24 to 1.91), and all-cause mortality increased by 68% (HR = 1.68; 95% CI = 1.44 to 1.96). Current smoking increased the probability of recurrence by 41% (HR = 1.41; 95% CI = 1.16 to 1.71), increased breast cancer mortality by 60% (HR = 1.61; 95% CI = 1.28 to 2.03), and doubled the risk of all-cause mortality (HR = 2.17; 95% CI = 1.85 to 2.54).

CONCLUSIONS

Lifetime cigarette smoking was statistically significantly associated with a poor prognosis among women diagnosed with breast cancer, dose-dependent increased risks of recurrence, and breast cancer and all-cause mortality.

A prospective study of circulating C-reactive protein, interleukin-6, and tumor necrosis factor α receptor 2 levels and risk of ovarian cancer

Chronic inflammation may play a role in ovarian carcinogenesis. We examined associations between 3 plasma biomarkers of inflammation-C-reactive protein (CRP), interleukin 6, and tumor necrosis factor α receptor 2-and risk of invasive epithelial ovarian cancer in prospectively collected samples from the Nurses' Health Study (NHS; 1989-2010), Nurses' Health Study II (NHS II; 1996-2009), and the Women's Health Study (WHS; 1992-2011) and performed a meta-analysis including data from previous publications. Associations with ovarian cancer risk were calculated using logistic regression (NHS/NHS II; n = 217 cases) or Cox proportional hazards regression (WHS; n = 159 cases). Study-specific results were combined using random-effects meta-analysis. In the NHS/NHS II and WHS, we observed a 53% increased risk of invasive ovarian cancer when comparing women in the fourth quartile of CRP with women in the first quartile (95% confidence interval (CI): 1.05, 2.23). A CRP level of >10 mg/L versus a level of ≤1 mg/L was associated with a 2.16-fold increased risk (95% CI: 1.23, 3.78). In a meta-analysis of published studies, women in the third tertile of CRP had a 35% increased risk (95% CI: 1.10, 1.67) compared with women in the first tertile. There were no significant associations between interleukin 6 or tumor necrosis factor α receptor 2 and risk in the NHS/NHS II. Our results support the hypothesis that higher levels of circulating CRP are associated with increased risk of ovarian cancer, indicating that the role of inflammation in ovarian cancer requires further elucidation.

Phospholipase A2G1B polymorphisms and risk of colorectal neoplasia

Pancreatic phospholipase A2, product of PLA2G1B, catalyzes the release of fatty acids from dietary phospholipids.Diet is the ultimate source of arachidonic acid in cellular phospholipids, precursor of eicosanoid signaling molecules, linked to inflammation, cell proliferation and colorectal carcinogenesis. We evaluated the association of PLA2G1B tagging single-nucleotide polymorphisms with colorectal neoplasia risk. A linkage-disequilibrium-based tagSNP algorithm (r(2)=0.90, MAF≥4%) identified three tagSNPs. The SNPs were genotyped on the Illumina platform in three population-based, case-control studies: colon cancer (1424 cases/1780 controls); rectal cancer (583/775); colorectal adenomas (485/578). Evaluating gene-wide associations, principal-component and haplotype analysis were conducted, individual SNPs were evaluated by logistic regression. Two PLA2G1B variants were statistically significantly associated with reduced risk of rectal cancer (rs5637, 3702 G>A Ser98Ser, p-trend=0.03; rs9657930, 1593 C>T, p-trend=0.01); principal component analysis showed that genetic variation in the gene overall was statistically significantly associated with rectal cancer (p=0.02). NSAID users with the rs2070873 variant had a reduced rectal cancer risk (P-inter=0.02). Specific associations were observed with tumor subtypes (TP53/KRAS). The results suggest that genetic polymorphisms in PLA2G1B affect susceptibility to rectal cancer.

Postdiagnosis cruciferous vegetable consumption and breast cancer outcomes: a report from the After Breast Cancer Pooling Project

Cruciferous vegetables are a major source of glucosinolate-derived bioactive compounds such as isothiocyanates, which have been shown in animal and in vitro studies to inhibit cancer growth and progression. Few studies have investigated cruciferous vegetable intake after diagnosis and breast cancer outcomes. Using data from the After Breast Cancer Pooling Project, which includes prospective data from U.S. and Chinese breast cancer survivors, we evaluated the association of cruciferous vegetables with breast cancer outcomes. Analyses included 11,390 women diagnosed with stage I-III invasive breast cancer (1990-2006) from four cohorts. Cruciferous vegetable intake (g/day) was assessed using food frequency questionnaires (mean of 22 months postdiagnosis). Study heterogeneity was evaluated by the Q statistic; hazard ratios (HRs) and 95% confidence intervals (CI) were estimated using delayed-entry Cox regression models stratified by study. After a median follow-up of 9.0 years, 1,725 deaths and 1,421 recurrences were documented. In pooled analyses using study-specific quartiles, cruciferous vegetable intake was not associated with breast cancer outcomes, adjusting for known clinical prognostic factors and selected lifestyle factors. HRs (95% CIs) by increasing quartiles (reference = lowest quartile) were 1.08 (0.93-1.25), 1.01 (0.87-1.18), and 1.10 (0.95-1.28) for recurrence (P(trend) = 0.34) and 1.01 (0.88-1.15), 0.97 (0.84-1.11), and 0.99 (0.86-1.13) for total mortality (P(trend) = 0.84). No associations were observed for subgroups defined by estrogen receptor status, stage, or tamoxifen therapy. Cruciferous vegetable intake at approximately two years after diagnosis was not associated with recurrence or mortality. Our results do not support an association between postdiagnosis cruciferous vegetable intake and breast cancer outcomes.

Postdiagnosis supplement use and breast cancer prognosis in the After Breast Cancer Pooling Project

Vitamin supplement use after breast cancer diagnosis is common, but little is known about long-term effects on recurrence and survival. We examined postdiagnosis supplement use and risk of death or recurrence in the After Breast Cancer Pooling Project, a consortium of four cohorts of 12,019 breast cancer survivors from the United States and China. Post-treatment supplement use (vitamins A, B, C, D, E, and multivitamins) was assessed 1-5 years postdiagnosis. Associations with risk of recurrence, breast cancer-specific mortality, or total mortality were analyzed in Cox proportional hazards models separately by cohort. Individual cohort results were combined using random effects meta-analysis. Interactions with smoking, treatment, and hormonal status were examined. In multivariate models, vitamin E was associated with a decreased risk of recurrence (RR: 0.88; 95 % CI 0.79-0.99), and vitamin C with decreased risk of death (RR: 0.81; 95 % CI 0.72-0.92). However, when supplements were mutually adjusted, all associations were attenuated. There were no statistically significant associations with breast cancer mortality. The use of antioxidant supplements (multivitamins, vitamin C, or E) was not associated with recurrence, but was associated with a 16 % decreased risk of death (95 % CI 0.72-0.99). In addition, vitamin D was associated with decreased risk of recurrence among ER positive, but not ER negative tumors (p-interaction = 0.01). In this large consortium of breast cancer survivors, post-treatment use of vitamin supplements was not associated with increased risk of recurrence or death. Post-treatment use of antioxidant supplements was associated with improved survival, but the associations with individual supplement were difficult to determine. Stratification by ER status and considering antioxidants as a group may be more clinically relevant when evaluating associations with cancer risk and mortality.

Abstract 127: Hormonal and reproductive risk factors for fatal breast cancer

Introduction: Although survival from breast cancer is high (5-year survival: 88%), a subset of breast cancers are ultimately fatal. Pre-diagnosis lifestyle factors may influence which patients will die due to their disease. Examining the incidence of fatal breast cancer specifically is important for elucidating these factors, because most women with breast cancer do not die of the disease, and a specific effect on aggressiveness could be missed. Thus, in the Nurses’ Health Study cohorts (NHS and NHSII), we evaluated risk factors for fatal breast cancer.

Methods: Any woman who died due to breast cancer at any time post-diagnosis was considered a fatal case. Hazards ratios (HRs) and 95% confidence intervals (CIs) for the association of reproductive and hormonal factors with incidence of fatal breast cancer were calculated using Cox proportional hazards regression. NHS and NHSII were combined using meta-analysis. Fatal and non-fatal cases were also compared for heterogeneity using competing risks analysis. For this analysis, we restricted to women who had had 15 years of post-diagnosis follow-up and defined a fatal case as any case for whom death due to breast cancer occurred within 15 years of diagnosis.

Results: We documented 1,736 fatal cases of breast cancer over 30 years of follow-up in NHS and 275 cases over 20 years of follow-up in NHSII. Similar to incidence of total breast cancer, increasing parity, younger age at first birth, and older age at menarche, and younger age at menopause tended to be associated with decreased risk of fatal breast cancer (Table). Compared to non-fatal cases, increasing age, age at first birth, age at natural menopause and time since quitting smoking were more strongly associated with fatal breast cancer than with non-fatal breast cancer(p-heterogeneity&lt;0.05).

Table. Associations between reproductive and hormonal factors and risk of fatal breast cancer in the Exposure Total cases Fatal cases HR (95% CI) HR (95% CI) N = 12,262 N = 2,011 Parity Ever Parous 1.01 (0.94–1.09) 0.87 (0.72–1.04) Number of children among parous 0.95 (0.94–0.97) 0.97 (0.94–1.00) Age at first birth (among parous women) continuous, per 5 year increase 1.15 (1.12–1.19) 1.15 (1.07–1.22) Duration of breastfeeding (among parous women), per 1 year increase 0.98* (0.92–1.04) 1.03 (0.99–1.06) Age at menarche, continuous, per 1 year increase 0.97 (0.96–0.98) 0.97 (0.94–1.00) Age at natural menopause Pre/Unknown 1.03 (0.95–1.13) 0.85 (0.70–1.04) &lt;45 0.77* (0.51–1.16) 0.71 (0.38–1.35) 45-&lt;50 0.90 (0.84–0.97) 0.96 (0.58–1.60) 50-&lt;53 1.00 (ref.) 1.00 (ref.) 53+ 1.03 (0.88–1.20) 1.05 (0.86–1.27) Oral contraceptive use Ever use 1.01 (0.96–1.05) 1.02 (0.92–1.13) Duration of use, per 5 year increase 1.03 (1.00–1.07) 1.07 (1.00–1.14) Tubal ligation 1.01 (0.96–1.06) 0.97 (0.81–1.16) Oophorectomy None 1.00 (ref.) 1.00 (ref.) 1 ovary removed 0.95 (0.88–1.04) 0.67 (0.52–0.87) both ovaries removed 0.86 (0.66–1.13) 0.95 (0.79–1.14) unknown number of ovaries removed 1.04 (0.76–1.41) 1.55 (0.89–2.72) Hysterectomy None 1.00 (ref.) 1.00 (ref.) Hysterectomy with no oophorectomy 0.96 (0.89–1.04) 0.86 (0.67–1.11) Hysterectomy with at least one ovary removed 0.80* (0.58–1.10) 0.80 (0.66–0.98) Smoking Never 1.00 (ref.) 1.00 (ref.) Former 1.07 (1.03–1.11) 0.97 (0.88–1.08) Current 1.02 (0.97–1.08) 1.02 (0.90–1.15) Time since quitting Current smoker 1.00 (ref.) 1.00 (ref.) &lt;10 years 1.06 (0.98–1.14) 0.93 (0.78–1.11) 10–19 years 1.10 (0.94–1.29) 1.10 (0.81–1.50) 20+ years 0.97 (0.86–1.09) 0.90 (0.75–1.07) Never smoker 0.96 (0.92–1.02) 0.98 (0.87–1.10) Family history of breast cancer Any 1st degree family history 1.67 (1.50–1.85) 1.47 (1.28–1.68) Per number of relatives with breast cancer 1.62 (1.45–1.80) 1.47 (1.30–1.67) All models are adjusted for age, birth index, family history of breast cancer, history of benign breast disease, BMI, alcohol intake, age at menarche, physical activity, duration of OC use, menopause status, PMH use (by type), and age at menopause *p-heterogeneity between NHS and NHSII &gt;0.05

Conclusion: Increasing age, age at first birth, and time since quitting smoking are more strongly associated with fatal breast cancer, suggesting that these factors may help predict which women are at risk of more aggressive breast cancers.

Citation Format: Elizabeth M. Poole, A. Heather Eliassen, Susan E. Hankinson, Bernard A. Rosner, Walter C. Willett, Rulla M. Tamimi, Shelley S. Tworoger. Hormonal and reproductive risk factors for fatal breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 127. doi:10.1158/1538-7445.AM2013-127

GWAS meta-analysis and replication identifies three new susceptibility loci for ovarian cancer

Genome-wide association studies (GWAS) have identified four susceptibility loci for epithelial ovarian cancer (EOC), with another two suggestive loci reaching near genome-wide significance. We pooled data from a GWAS conducted in North America with another GWAS from the UK. We selected the top 24,551 SNPs for inclusion on the iCOGS custom genotyping array. We performed follow-up genotyping in 18,174 individuals with EOC (cases) and 26,134 controls from 43 studies from the Ovarian Cancer Association Consortium. We validated the two loci at 3q25 and 17q21 that were previously found to have associations close to genome-wide significance and identified three loci newly associated with risk: two loci associated with all EOC subtypes at 8q21 (rs11782652, P = 5.5 × 10(-9)) and 10p12 (rs1243180, P = 1.8 × 10(-8)) and another locus specific to the serous subtype at 17q12 (rs757210, P = 8.1 × 10(-10)). An integrated molecular analysis of genes and regulatory regions at these loci provided evidence for functional mechanisms underlying susceptibility and implicated CHMP4C in the pathogenesis of ovarian cancer.

Multiple independent variants at the TERT locus are associated with telomere length and risks of breast and ovarian cancer

TERT-locus SNPs and leukocyte telomere measures are reportedly associated with risks of multiple cancers. Using the Illumina custom genotyping array iCOGs, we analyzed ∼480 SNPs at the TERT locus in breast (n = 103,991), ovarian (n = 39,774) and BRCA1 mutation carrier (n = 11,705) cancer cases and controls. Leukocyte telomere measurements were also available for 53,724 participants. Most associations cluster into three independent peaks. The minor allele at the peak 1 SNP rs2736108 associates with longer telomeres (P = 5.8 × 10(-7)), lower risks for estrogen receptor (ER)-negative (P = 1.0 × 10(-8)) and BRCA1 mutation carrier (P = 1.1 × 10(-5)) breast cancers and altered promoter assay signal. The minor allele at the peak 2 SNP rs7705526 associates with longer telomeres (P = 2.3 × 10(-14)), higher risk of low-malignant-potential ovarian cancer (P = 1.3 × 10(-15)) and greater promoter activity. The minor alleles at the peak 3 SNPs rs10069690 and rs2242652 increase ER-negative (P = 1.2 × 10(-12)) and BRCA1 mutation carrier (P = 1.6 × 10(-14)) breast and invasive ovarian (P = 1.3 × 10(-11)) cancer risks but not via altered telomere length. The cancer risk alleles of rs2242652 and rs10069690, respectively, increase silencing and generate a truncated TERT splice variant.

Acrylamide hemoglobin adduct levels and ovarian cancer risk: a nested case-control study

BACKGROUND

Acrylamide is a probable human carcinogen formed during cooking of starchy foods. Two large prospective cohort studies of dietary acrylamide intake and ovarian cancer risk observed a positive association, although two other studies reported no association.

METHODS

We measured acrylamide exposure using red blood cell acrylamide and glycidamide hemoglobin adducts among women in two large prospective cohorts: the Nurses' Health Study and Nurses' Health Study II. Between blood collection and 2010, we identified 263 incident cases of epithelial ovarian cancer, matching two controls per case. We used logistic regression models to examine the association between acrylamide exposure and ovarian cancer risk, adjusting for matching factors, family history of ovarian cancer, tubal ligation, oral contraceptive use, body mass index, parity, alcohol intake, smoking, physical activity, and caffeine intake.

RESULTS

The multivariate-adjusted relative risk (RR) of ovarian cancer comparing the highest versus lowest tertile of total acrylamide adducts was 0.79 (95% CI, 0.50-1.24, P trend = 0.08). The comparable RR of ovarian cancer among non-smokers at blood draw was 0.85 (95% CI, 0.57-1.27, P trend = 0.14). The association did not differ by tumor histology (serous invasive versus not), P for heterogeneity = 0.86. Individual adduct types (acrylamide or glycidamide) were not associated with risk.

CONCLUSIONS

We observed no evidence that acrylamide exposure as measured by adducts to hemoglobin is associated with an increased risk of ovarian cancer.

IMPACT

Our finding indicates that acrylamide intake may not increase risk of ovarian cancer.

Ovarian cancer risk factors by tumor dominance, a surrogate for cell of origin

Differentiating ovarian tumors based on developmental pathway may further enhance our understanding of the disease. Traditionally, ovarian cancers were thought to arise from the ovarian surface epithelium; however, recent evidence suggests that some tumors originate in the fallopian tube. We classified cases in a population-based case-control study (New England Case-Control [NECC] Study) and two cohort studies (Nurses' Health Study [NHS]/Nurses' Health Study II [NHSII]) by tumor dominance, a proxy for tissue of origin. Dominant tumors (likely ovarian origin) are restricted to one ovary or are at least twice as large on one ovary compared to the other. Ovarian cancer risk factors were evaluated in relation to dominant and nondominant tumors (likely tubal origin) using polytomous logistic regression (NECC) or competing risks Cox models (NHS/NHSII). Results were combined using random-effects meta-analyses. Among 1,771 invasive epithelial ovarian cancer cases, we observed 1,089 tumors with a dominant mass and 682 with no dominant mass. Dominant tumors were more likely to be mucinous, endometrioid or clear cell, whereas nondominant tumors were more likely to be serous. Tubal ligation, two or more births, endometriosis and age were more strongly associated with dominant tumors (rate ratio [RR] = 0.60, 0.83, 1.58 and 1.37, respectively) than nondominant tumors (RR = 1.03, 0.93, 0.84 and 1.14, respectively; p-difference = 0.0001, 0.01, 0.0003 and 0.01, respectively). These data suggest that risk factors for tumors putatively arising from ovarian versus fallopian tube sites may differ; in particular, reproductive factors may be more important for ovarian-derived tumors. As this is the first study to evaluate ovarian cancer risk factors by tumor dominance, these results need to be validated by other studies.

Genetic variation in the lipoxygenase pathway and risk of colorectal neoplasia

Arachidonate lipoxygenase (ALOX) enzymes metabolize arachidonic acid to generate potent inflammatory mediators and play an important role in inflammation-associated diseases. We investigated associations between colorectal cancer risk and polymorphisms in ALOX5, FLAP, ALOX12, and ALOX15, and their interactions with nonsteroidal anti-inflammatory drug (NSAID) use. We genotyped fifty tagSNPs, one candidate SNP, and two functional promoter variable nucleotide tandem repeat (VNTR) polymorphisms in three US population-based case-control studies of colon cancer (1,424 cases/1,780 controls), rectal cancer (583 cases/775 controls), and colorectal adenomas (485 cases/578 controls). Individuals with variant genotypes of the ALOX5 VNTR had a decreased risk of rectal cancer, with the strongest association seen for individuals with one or more alleles of >5 repeats (wild type = 5, OR>5/≥5 = 0.42, 95% CI 0.20-0.92; P = 0.01). Four SNPs in FLAP (rs17239025), ALOX12 (rs2073438), and ALOX15 (rs4796535 and rs2619112) were associated with rectal cancer risk at P ≤ 0.05. One SNP in FLAP (rs12429692) was associated with adenoma risk. A false discovery rate (FDR) was applied to account for false positives due to multiple testing; the ALOX15 associations were noteworthy at 25% FDR. Colorectal neoplasia risk appeared to be modified by NSAID use in individuals with variant alleles in FLAP and ALOX15. One noteworthy interaction (25% FDR) was observed for rectal cancer. Genetic variability in ALOXs may affect risk of colorectal neoplasia, particularly for rectal cancer. Additionally, genetic variability in FLAP and ALOX15 may modify the protective effect of NSAID use against colorectal neoplasia.

Hormonal and reproductive risk factors for epithelial ovarian cancer by tumor aggressiveness

BACKGROUND

Approximately half of epithelial ovarian cancers are fatal within 3 years; however, roughly 35% of women survive for at least 10 years. In the Nurses' Health Study, New England Case-Control Study, Australian Ovarian Cancer Study, and NIH-AARP Diet and Health Study, we investigated potential differences in the associations with ovarian cancer risk factors by tumor aggressiveness, defined on the basis of time from diagnosis until death.

METHODS

We calculated relative risks (RR) and 95% confidence intervals (CI) for associations of known or suspected ovarian cancer risk factors with rapidly fatal (death within 3 years of diagnosis) and less aggressive tumors (all others) using Cox proportional hazards competing risks analysis (NHS and AARP) or polytomous logistic regression (NECC, AOCS). Results were combined using random effects meta-analysis.

RESULTS

Increasing age was associated with greater risk of rapidly fatal versus less aggressive disease (RR, 5-year increase: 1.39; 95% CI, 1.29-1.49 vs. RR, 1.09; 95% CI, 1.03-1.16, respectively; Pdiff < 0.0001). Oral contraceptive use was associated with a greater decreased risk of rapidly fatal (RR, 5-year increase: 0.69; 95% CI, 0.58-0.82) versus less aggressive disease (RR, 0.81; 95% CI, 0.74-0.89; Pdiff, 0.002). Conversely, increasing parity was associated only with less aggressive disease (RR per child, 0.87; 95% CI, 0.81-0.93).

CONCLUSION

In this analysis of 4,342 cases, there were clear differences in risk factors for rapidly fatal versus less aggressive ovarian tumors.

IMPACT

Differences in risk factor associations by tumor aggressiveness suggests the developmental pathways through which the tumors develop and may be important for developing primary preventive strategies for the most aggressive cancers.

Identification and molecular characterization of a new ovarian cancer susceptibility locus at 17q21.31

Epithelial ovarian cancer (EOC) has a heritable component that remains to be fully characterized. Most identified common susceptibility variants lie in non-protein-coding sequences. We hypothesized that variants in the 3' untranslated region at putative microRNA (miRNA)-binding sites represent functional targets that influence EOC susceptibility. Here, we evaluate the association between 767 miRNA-related single-nucleotide polymorphisms (miRSNPs) and EOC risk in 18,174 EOC cases and 26,134 controls from 43 studies genotyped through the Collaborative Oncological Gene-environment Study. We identify several miRSNPs associated with invasive serous EOC risk (odds ratio=1.12, P=10(-8)) mapping to an inversion polymorphism at 17q21.31. Additional genotyping of non-miRSNPs at 17q21.31 reveals stronger signals outside the inversion (P=10(-10)). Variation at 17q21.31 is associated with neurological diseases, and our collaboration is the first to report an association with EOC susceptibility. An integrated molecular analysis in this region provides evidence for ARHGAP27 and PLEKHM1 as candidate EOC susceptibility genes.

Epigenetic analysis leads to identification of HNF1B as a subtype-specific susceptibility gene for ovarian cancer

HNF1B is overexpressed in clear cell epithelial ovarian cancer, and we observed epigenetic silencing in serous epithelial ovarian cancer, leading us to hypothesize that variation in this gene differentially associates with epithelial ovarian cancer risk according to histological subtype. Here we comprehensively map variation in HNF1B with respect to epithelial ovarian cancer risk and analyse DNA methylation and expression profiles across histological subtypes. Different single-nucleotide polymorphisms associate with invasive serous (rs7405776 odds ratio (OR)=1.13, P=3.1 × 10(-10)) and clear cell (rs11651755 OR=0.77, P=1.6 × 10(-8)) epithelial ovarian cancer. Risk alleles for the serous subtype associate with higher HNF1B-promoter methylation in these tumours. Unmethylated, expressed HNF1B, primarily present in clear cell tumours, coincides with a CpG island methylator phenotype affecting numerous other promoters throughout the genome. Different variants in HNF1B associate with risk of serous and clear cell epithelial ovarian cancer; DNA methylation and expression patterns are also notably distinct between these subtypes. These findings underscore distinct mechanisms driving different epithelial ovarian cancer histological subtypes.