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.

Postdiagnosis alcohol consumption and breast cancer prognosis in the after breast cancer pooling project

BACKGROUND

Alcohol consumption is an established risk factor for incident breast cancer. However, its role in breast cancer prognosis remains unclear.

METHODS

We conducted an investigation of postdiagnosis alcohol consumption with recurrence and mortality among 9,329 breast cancer patients in the After Breast Cancer Pooling Project. Women were diagnosed from 1990 to 2006 with AJCC Stage I-III breast tumors from three prospective US cohorts. Alcohol intake was assessed at cohort entry (mean 2.1 years postdiagnosis) using a food frequency questionnaire. HR and 95% confidence intervals (CI) were estimated using delayed entry Cox proportional hazards models with adjustment for known prognostic factors.

RESULTS

After a mean follow-up of 10.3 years, 1,646 recurrences and 1,543 deaths were ascertained. 5,422 women (58%) were considered drinkers (≥0.36 g/day of alcohol, ≥0.25 drinks/week) with a median of 5.3 g/day. Overall, compared with nondrinking, regular alcohol intake (≥6.0 g/day) was not associated with risk of recurrence (HR for 6 to less than 12 g/day, 1.03; 95% CI, 0.86-1.24; HR for 12 to less than 24 g/day, 1.12; 95% CI, 0.93-1.34; HR for ≥24 g/day, 1.04; 95% CI, 0.84-1.31). However, risk varied significantly by menopausal status (P for interaction < 0.05). Postmenopausal women who regularly consumed alcohol (≥6.0 g/day) had increased risk of recurrence (HR, 1.19; 95% CI, 1.01-1.40). Alcohol intake was not associated with mortality.

CONCLUSIONS

Regular alcohol consumption was not associated with breast cancer recurrence and total mortality overall, yet recurrence risk was only elevated in postmenopausal women.

IMPACT

The association between alcohol intake and recurrence may depend on menopausal status at breast cancer diagnosis.

Abstract 73: Evaluation of bead-based assays of inflammation markers for epidemiologic studies

Given finite sample availability in epidemiologic studies, minimizing assay volumes is an important consideration in studies of biomarker-disease relationships. Consequently, there is great interest in multiplex assays that use less volume than standard assays and provide data on multiple markers in one assay. This is particularly true for markers of inflammation, a key factor in cancer and other age-related diseases. Therefore, we conducted pilot studies of three bead-based, multiplex, inflammatory marker panels at three laboratories. The first pilot evaluated assay reproducibility by calculating the coefficient of variation (CV) using 12 blinded replicate samples, and the second evaluated the role of delayed processing using samples from 12 participants who had one-third of their sample processed immediately after blood draw, and one-third each processed 24 and 48 hours later. Minimum criteria for an analyte to pass the pilots were: (1) &gt;50% of samples had levels above the limit of detection (LOD), (2) a CV ≤20%, and (3) an intraclass correlation across processing times &gt;0.80. For Panel 1, 200uL of plasma was used to assess 10 biomarkers in 2007. For Panel 2, 50uL of plasma was used to assess 17 markers in 2011. For Panel 3, 250uL of plasma was used to assess 12 markers in 2012. More than half of the biomarkers in two of the panels (1 and 3) had &gt;50% of samples with levels less than the LOD; in Panel 2 29% of biomarkers had &gt;50% of samples below the LOD. Of the biomarkers with more than half the samples above the LOD, all had CVs &lt;20%. Overall, 3 (30%) of markers passed the LOD and CV criteria in Panel 1, 12 (71%) passed in Panel 2, and 4 (33%) passed in Panel 3. Among these, none of the markers in Panels 1 and 3 and 7 markers in Panel 2 were stable with delayed processing, resulting in an overall pass rate of 0% in Panels 1 and 3 and 41% in Panel 2. Further, for Panel 2, we observed that the correlation between the multiplex and the standard ELISA for IL-6 was only 0.25. Our results suggest that assessing inflammatory markers on bead-based multiplex platforms may not be appropriate for epidemiologic studies, possibly reflecting poor assay optimization for specific biomarkers and thus lowered overall assay sensitivity and specificity.

Citation Format: Elizabeth M. Poole, Mary K. Townsend, A Heather Eliassen, Janine Neville-Golden, Shelley S. Tworoger. Evaluation of bead-based assays of inflammation markers for epidemiologic studies. [abstract]. In: Proceedings of the AACR Special Conference on Post-GWAS Horizons in Molecular Epidemiology: Digging Deeper into the Environment; 2012 Nov 11-14; Hollywood, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(11 Suppl):Abstract nr 73.

CYP2C9 variants increase risk of colorectal adenoma recurrence and modify associations with smoking but not aspirin treatment

PURPOSE

The cytochrome P450 2C9 enzyme (CYP2C9) is involved in metabolism of endogenous compounds, drugs, and procarcinogens. Two common nonsynonymous polymorphisms in CYP2C9 are associated with reduced enzyme activity: CYP2C9*2 (rs1799853, R144C) and CYP2C9*3 (rs1057910, I359L).

METHODS

We investigated whether CYP2C9 genotype was associated with risk of colorectal adenoma and/or modified associations with aspirin treatment or cigarette smoking in a cohort of 928 participants in a randomized trial of aspirin chemoprevention. Generalized linear regression was used to compute relative risks (RRs) and 95 % confidence intervals (95 % CIs). Multiplicative interactions terms were used to assess effect modification.

RESULTS

CYP2C9 genotype was associated with increased risks for adenoma recurrence of 29 % (RR = 1.29, 95 % CI 1.09-1.51) for ≥1 variant allele (CYP2C9*2 or *3) and 47 % (RR = 1.47, 95 % CI 1.19-1.83) for ≥1 CYP2C9*3 allele. The risk for advanced lesions or multiple (≥3) adenomas was increased by 64 % (RR = 1.64, 95 % CI 1.18-2.28) for ≥1 variant allele (CYP2C9*2 or *3) and 79 % (RR = 1.79, 95 % CI 1.16-2.75) for ≥1 CYP2C9*3 allele. Genotype modified associations with smoking, but not aspirin treatment. The adenoma risk was increased by 26 % (RR = 1.26, 95 % CI 0.99-1.58) for former smokers and 60 % (RR = 1.60, 95 % CI 1.19-2.15) for current smokers among wild-type individuals, but there was no increased risk among individuals with ≥1 variant allele (CYP2C9*2 or *3) (p (interaction) = 0.04).

CONCLUSIONS

Carriers of CYP2C9 variants with lower enzyme activity have increased overall risk of colorectal adenoma but reduced adenoma risk associated with cigarette smoking. These results may be due to effects on the synthesis of endogenous eicosanoids and/or reduced activation of procarcinogens in smoke by CYP2C9 variants.

IκBKβ and NFκB1, NSAID use and risk of colorectal cancer in the Colon Cancer Family Registry

The NFκB-signaling pathway regulates cell proliferation and inflammation. Activation of the pathway is implicated in the etiology of colorectal cancer (CRC). NSAIDs may reduce CRC risk partially through a nuclear factor-kappa B (NFκB)-dependent pathway. In this study, we investigated associations between 34 NFκB1 and 8 IκBKβ tagSNPs and CRC risk and examined interactions with non-steroidal anti-inflammatory drug (NSAID) use. Using conditional logistic regression, we investigated these associations among 1584 incident CRC cases and 2516 sibling controls from the Colon Cancer Family Registry. Three IκBKβ SNPs were associated with a statistically significant lower colorectal or colon cancer risk: rs9694958 (A>G intron 5) (colorectal: OR(hzv) = 0.26(0.07-0.99), P(trend) = 0.048, P(adj) = 0.25), rs10958713 (A>C intron 19) (colon: OR(hzv) = 0.62(0.42-0.92), P(trend) = 0.005, P(adj) = 0.03) and rs5029748 (C>A intron 2) (colon: OR(het) = 0.72(0.56-0.91), P(trend) = 0.01, P(adj) = 0.08). We replicated trends associated with NFκB1 and IκBKβ variants identified in a previous study (rs4648110 (T>A intron 22), rs13117745 (G>A intron 5) and rs3747811 (T>A intron 1)). IκBKβ's rs6474387 (C>T intron 20) and rs11986055 (A>C intron 2) showed substantially lower colon cancer risk among current NSAID users (P(interaction) = 0.01 and P(interaction) = 0.045, respectively), whereas NFκB1's rs230490 (G>A 5' (outside UTR)) and rs997476 (C>A 3' (outside UTR)) showed higher CRC risk among current NSAID users (P(interaction) = 0.01 and P(interaction) = 0.03, respectively). These findings suggest that variants in NFκB1 and IκBKβ are associated with CRC risk and NSAIDs may function partially through an NFκB-dependent pathway. The SNPs identified here should be considered for future functional studies and may be useful in designing a pharmacogenetic approach to preventive NSAID use.

ABO blood group and risk of epithelial ovarian cancer within the Ovarian Cancer Association Consortium

PURPOSE

Previous studies have examined the association between ABO blood group and ovarian cancer risk, with inconclusive results.

METHODS

In eight studies participating in the Ovarian Cancer Association Consortium, we determined ABO blood groups and diplotypes by genotyping 3 SNPs in the ABO locus. Odds ratios and 95 % confidence intervals were calculated in each study using logistic regression; individual study results were combined using random effects meta-analysis.

RESULTS

Compared to blood group O, the A blood group was associated with a modestly increased ovarian cancer risk: (OR: 1.09; 95 % CI: 1.01-1.18; p = 0.03). In diplotype analysis, the AO, but not the AA diplotype, was associated with increased risk (AO: OR: 1.11; 95 % CI: 1.01-1.22; p = 0.03; AA: OR: 1.03; 95 % CI: 0.87-1.21; p = 0.76). Neither AB nor the B blood groups were associated with risk. Results were similar across ovarian cancer histologic subtypes.

CONCLUSION

Consistent with most previous reports, the A blood type was associated modestly with increased ovarian cancer risk in this large analysis of multiple studies of ovarian cancer. Future studies investigating potential biologic mechanisms are warranted.

A comparison of approaches for association studies of polymorphisms and colorectal cancer risk

AIM

Meta-analyses have been used to evaluate associations between polymorphisms and colorectal cancer risk, but the quality of individual studies used to inform them may vary substantially. Our aim was to apply well-established quality-control criteria to individual association studies and then compare the results of meta-analyses that included or excluded studies that did not meet these criteria.

METHOD

We used meta-analyses of studies reporting a relationship between polymorphisms and colorectal cancer published between 1996 and 2008. Polymorphism-cancer associations were derived in separate meta-analyses including only those meeting the quality-control criteria.

RESULTS

Relative ORs varied substantially between the open and restricted group meta-analyses for all variants except MTHFR 677 CT. However, the associations were modest and the direction of relative risk did not change after applying criteria. Publication bias was detected for all associations, except the restricted set of studies for GSTP1 GG.

CONCLUSION

We observed variation in calculated relative risk and changes in tests for publication bias that were dependent on the inclusion criteria used for association studies of polymorphisms and colorectal cancer. Standardizing study inclusion criteria may reduce the variation in findings for meta-analyses of gene-association studies of common diseases such as colorectal cancer.

Genetic variability in IGF-1 and IGFBP-3 and body size in early life

Background

Early life body size and circulating levels of IGF-1 and IGFBP-3 have been linked to increased risks of breast and other cancers, but it is unclear whether these exposures act through a common mechanism. Previous studies have examined the role of IGF-1 and IGFBP-3 genetic variation in relation to adult height and body size, but few studies have examined associations with birthweight and childhood size.

Methods

We examined whether htSNPs in IGF-1 and the IGFBP-1/IGFBP-3 gene region are associated with the self-reported outcomes of birthweight, body fatness at ages 5 and 10, and body mass index (BMI) at age 18 among healthy women from the Nurses’ Health Study (NHS) and NHSII. We used ordinal logistic regression to model odds ratios (ORs) and 95% confidence intervals (CI) of a one category increase for birthweight and somatotypes at ages 5 and 10. We used linear regression to model associations with BMI at age 18.

Results

Among 4567 healthy women in NHS and NHSII, we observed no association between common IGF-1 or IGFBP-1/IGFBP-3 SNPs and birthweight, body fatness at ages 5 and 10, or BMI at age 18.

Conclusions

Common IGF-1 and IGFBP-1/IGFBP-3 SNPs are not associated with body size in early life.

Metabolic, hormonal and immunological associations with global DNA methylation among postmenopausal women

DNA methylation is an epigenetic modification essential for the regulation of gene expression that has been implicated in many diseases, including cancer. Few studies have investigated the wide range of potential predictors of global DNA methylation, including biomarkers. Here, we investigated associations between DNA methylation and dietary factors, sex-steroid hormones, metabolic, lipid, inflammation, immune and one-carbon biomarkers. Data and baseline biomarker measurements were obtained from 173 overweight/obese postmenopausal women. Global DNA methylation in lymphocyte DNA was measured using the pyrosequencing assay for LINE-1 repeats. We used correlations and linear regression analyses to investigate associations between continuous data and DNA methylation, while t-tests were used for categorical data. Secondary analyses stratified by serum folate levels and multivitamin use were also conducted. There was little variability in LINE-1 methylation (66.3-79.5%). Mean LINE-1 methylation was significantly higher among women with elevated glucose levels. Mean LINE-1 methylation was also higher among women with high CD4+/CD8+ ratio, and lower among women with elevated vitamin B6, but neither reached statistical significance. In analyses stratified by folate status, DNA methylation was negatively associated with sex hormone concentrations (estrone, estradiol, testosterone and sex hormone binding globulin) among women with low serum folate levels (n = 53). Conversely, among women with high serum folate levels (n = 53), DNA methylation was positively associated with several immune markers (CD4/CD8 ratio, NK1656/lymphocytes and IgA). Results from this screening suggest that global DNA methylation is generally stable, with differential associations for sex hormones and immune markers depending on one-carbon status.

Weight change and survival after breast cancer in the after breast cancer pooling project

BACKGROUND

Weight change after a breast cancer diagnosis has been linked to lower survival. To further understand effects of postdiagnostic weight variation on survival, we examined the relationship by comorbid status and initial body mass index (BMI).

METHODS

The current analysis included 12,915 patients with breast cancer diagnosed between 1990 and 2006 with stage I-III tumors from four prospective cohorts in the United States and China. HRs and 95% confidence intervals (CI) representing the associations of five weight change categories [within <5% (reference); 5%-<10% and ≥10% loss and gain] with mortality were estimated using Cox proportional hazards models.

RESULTS

Mean weight change was 1.6 kg. About 14.7% women lost and 34.7% gained weight. Weight stability in the early years postdiagnosis was associated with the lowest overall mortality risk. Weight loss ≥10% was related to a 40% increased risk of death (HR, 1.41; 95% CI, 1.14-1.75) in the United States and over three times the risk of death (HR, 3.25; 95% CI: 2.24, 4.73) in Shanghai. This association varied by prediagnosis BMI, and in the United States, lower survival was seen for women who lost weight and had comorbid conditions. Weight gain ≥10% was associated with a nonsignificant increased risk of death.

CONCLUSIONS

Prevention of excessive weight gain is a valid public health goal for breast cancer survivors. Although intentionality of weight loss could not be determined, women with comorbid conditions may be particularly at risk of weight loss and mortality.

IMPACT

Weight control strategies for breast cancer survivors should be personalized to the individual's medical history.

Genetic polymorphism CYP17 rs2486758 and metabolic risk factors predict daily salivary 17β-estradiol concentration in healthy premenopausal Norwegian women. The EBBA-I study

CONTEXT

The relationship between low-penetrance genes, metabolic risk factors, and levels of endogenous 17β-estradiol and progesterone, which play a role in breast cancer risk, remains unclear.

OBJECTIVE

The aim of this study was to determine whether common polymorphisms in CYP17, in combination with metabolic risk factors (individually or clustered), alter salivary concentrations of free biologically active 17β-estradiol and progesterone among healthy premenopausal Norwegian women.

DESIGN

Eight single nucleotide polymorphisms in CYP17 were genotyped in 203 healthy premenopausal women aged 25-35 yr in the Norwegian EBBA-I Study, conducted in 2000-2002. Daily salivary concentrations of 17β-estradiol and progesterone were measured throughout one menstrual cycle. A clustered metabolic score was calculated, including waist circumference, mean arterial pressure, insulin resistance, fasting triglycerides, and total cholesterol/high-density lipoprotein cholesterol ratio. The study hypothesis was tested in multivariable linear regression and generalized estimating equation models.

RESULTS

Women in the upper tertile of clustered metabolic score with the CYP17 rs2486758 minor allele had daily salivary 17β-estradiol concentrations that were 53% higher than other study women throughout the menstrual cycle (P < 0.001). Similarly, women in the upper tertile of total cholesterol/high-density lipoprotein cholesterol ratio, fasting triglycerides, and insulin resistance had 44, 32, and 24% higher daily salivary 17β-estradiol concentrations, respectively (all P < 0.05).

CONCLUSION

The CYP17 rs2486758 minor allele may predispose to higher 17β-estradiol levels, particularly in premenopausal women with a high clustered metabolic score. Thus, modification of metabolic risk factors may have significant implications for the prevention of breast cancer in women with the minor allele of CYP17 rs2486758.

Abstract 1004: Impact of genetic polymorphisms on colorectal adenoma recurrence and toxicity in a COX-2 inhibitor trial (Celecoxib): Results from a pilot study

Background: Chemoprevention trials have shown that Celecoxib, a selective COX-2 inhibitor can reduce adenoma recurrence but can also increase risk of cardiac toxicity. Therefore, in this pilot study, we evaluated the associations between genetic variation in several candidate pathways (e.g. prostaglandin, arachidonic acid and leukotriene synthesis), the incidence of adenoma recurrence as well as toxicity (any, gastrointestinal, cardiac, and non-gastrointestinal/non-cardiac toxicities). Methods: This analysis includes 119 Israeli patients with colorectal adenoma who participated in the Prevention of Colorectal Sporadic Adenomatous Polyps (PreSAP) trial. Reassessment followed after ∼3 years on Celecoxib, followed by 2 years off drug. Incidence of colorectal adenomas was measured by colonoscopy at years 1, 3, and 5. The presence of any, gastrointestinal, cardiac and non-gastrointestinal/non-cardiac toxicities was assessed by investigators for the on-treatment period and collected by patient self-report after treatment. A linkage-disequilibrium-based tagSNP selection algorithm (r2≥0.90, MAF≥4%) identified tagSNPs in candidate pathways. Genotyping was performed using IlluminaTM GoldenGate bead-based genotyping technology. Results: Multiple variants were associated with adenoma recurrence and toxicities. Variability, particularly in COX-1 (rs10306164, rs1236913, rs1330344, rs3119773), COX- 2 (rs4648268), and ALOX12 (rs2073438, rs2292350) played a major role in adenoma recurrence risk among patients on placebo compared to patients on Celecoxib. The highest risk was observed for the COX-1 rs3119773 variant (1890 G&gt;A intron 2) (HR=4.65, 95%CI 1.71-12.64, p=0.0026). Variants in COX2 (rs2206593, rs2745557), EGFR (rs1558544, rs17336919), ALOX15 (rs2619112, rs2619118, rs4796535), SRC (rs6018027, rs7269342), SEPP1 (rs230819, rs230820), and WNT6 (rs6747776, rs6754599) genes were associated with any toxicity. In contrast to gastrointestinal toxicity, a larger number of gene variants (especially variants in PGES, CRP, SRC and GPX3) were associated with increased risk of cardiac toxicity. The increased risk of cardiac toxicity associated with the SRC gene variants (rs6017996, rs6018256, rs6018257) ranged from 7- to 11-fold. Conclusion: Genetic polymorphisms in multiple inflammation-related genes appear to mediate the effect of Celecoxib on adenoma recurrence and the resultant toxicity, particularly cardiac toxicity. Identification of these genetic variants can potentially help in the provision of tailored and optimum care for colorectal adenoma patients. Larger studies validating these pharmacogenetic relationships are warranted.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1004. doi:1538-7445.AM2012-1004

Abstract 4488: Inflammation-related biomarkers and risk of epithelial ovarian cancer

Introduction: Chronic inflammation caused by ovulation-related wound healing is theorized to cause ovarian carcinogenesis. We examined associations between three plasma biomarkers of inflammation, CRP, IL-6, and TNFαR-2, and risk of epithelial ovarian cancer in a nested case-control study of ovarian cancer cases and controls from the Nurses’ Health Study (NHS) and NHSII as well as in the Women's Health Study (WHS) cohort (CRP only). We further performed a meta-analysis with previously published studies of these biomarkers and ovarian cancer. Methods: Associations between quartiles of CRP, IL-6, and TNFαR-2 and risk of epithelial ovarian cancer were calculated using unconditional logistic regression (NHS/NHSII) or Cox proportional hazards regression (WHS); NHS/NHSII and WHS were combined using random effects meta-analysis. All analyses were adjusted for age, menopausal status/post-menopausal hormone use, duration of oral contraceptive use, tubal ligation, parity, and body mass index. The NHS/NHSII analyses were additionally adjusted for blood draw characteristics (fasting status, time of day and month of draw). Random effects meta-analysis was used to combine these results with previously published results. Results: In the NHS/NHSII (n=218 cases) and WHS (n=159 cases), a 59% increased ovarian cancer risk was observed in the 4th quartile of CRP compared to the 1st quartile (95% CI: 1.08-2.34). Further, CRP &gt;10mg/L compared to &lt;1 mg/L, was associated with a 2.21-fold increased ovarian cancer risk (95% CI: 1.29-3.80). In meta-analyses with previously published studies, the 3rd compared to the 1st tertile of CRP was associated with a 41% increased risk (95% CI: 1.14-1.74) (Table). There were no statistically significant associations between quartiles of IL-6 or TNFαR2 and ovarian cancer risk in the NHS/NHSII or in a meta-analysis with a previous publication. Conclusion: Our results suggest that higher levels of circulating CRP, but not IL-6 or TNFαR2, are associated with increased risk of ovarian cancer.

Glutathione peroxidase tagSNPs: associations with rectal cancer but not with colon cancer

Glutathione peroxidases (GPXs) are selenium-dependent enzymes that reduce and, thus, detoxify hydrogen peroxide and a wide variety of lipid hydroperoxides. We investigated tagSNPs in GPX1-4 in relation to colorectal neoplasia in three independent study populations capturing the range of colorectal carcinogenesis from adenoma to cancer. A linkage-disequilibrium (LD)-based tagSNP selection algorithm (r(2) ≥ 0.90, MAF ≥ 4%) identified 21 tagSNPs. We used an identical Illumina platform to genotype GPX SNPs in three 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). For gene-level associations, we conducted principal component analysis (PCA); multiple logistic regression was used for single SNPs. Analyses were adjusted for age, sex, and study center and restricted to non-Hispanic white participants. Analyses of cancer endpoints were stratified by molecular subtypes. Without correction for multiple testing, one polymorphism in GPX2 and three polymorphisms in GPX3 were associated with a significant risk reduction for rectal cancer at α = 0.05, specifically for rectal cancers with TP53 mutations. The associations regarding the three polymorphisms in GPX3 remained statistically significant after adjustment for multiple comparisons. The PCA confirmed an overall association of GPX3 with rectal cancer (P = 0.03). No other statistically significant associations were observed. Our data provide preliminary evidence that genetic variability in GPX3 contributes to risk of rectal cancer but not of colon cancer and thus provide additional support for differences in underlying pathogenetic mechanisms for colon and rectal cancer.

Pre-diagnosis body mass index and survival after breast cancer in the After Breast Cancer Pooling Project

Obese and underweight women who develop breast cancer may have poorer survival compared with normal-weight women. However, the optimal weight for best prognosis is still under study. We conducted a prospective investigation of pre-diagnosis body mass index (BMI) and mortality among 14,948 breast cancer patients in the After Breast Cancer Pooling Project. Breast cancer patients diagnosed from 1990 to 2006 with AJCC Stage I-III breast tumors were drawn from four prospective cohorts. Hazard ratios (HR) and 95% confidence intervals (CI) representing the associations of BMI categories (World Health Organization international classifications) with recurrence and mortality were estimated using delayed entry Cox proportional hazards models. Obese (30 to < 35 kg/m(2)), severely obese (35 to < 40 kg/m(2)), and morbidly obese (≥ 40 kg/m(2)) were examined. After a mean follow-up of 7.8 years, 2,140 deaths and 2,065 recurrences were documented. Both underweight (HR = 1.59; 95% CI: 1.18, 2.13) and morbidly obese women (HR = 1.81; 95% CI: 1.42, 2.32) had the greatest risk of overall mortality compared with normal weight (18.5-24.9 kg/m(2)) women. Severe obesity (HR = 1.09; 95% CI: 0.88, 1.36) and obesity (HR = 1.11; 95% CI: 0.97, 1.27) were related to small non-significant increased risks. Overweight (25.0-29.9 kg/m(2)) was not associated with any excess risk compared with normal weight. Similar associations were found for breast cancer death and non-breast cancer death but not recurrence. Women who were underweight and morbidly obese before breast cancer diagnosis were at the greatest risk of all-cause mortality. Morbidly obese women were also at increased risk of death from breast cancer. These results suggest that degree of obesity confers differential risk on survival.

Genetic variability in IL23R and risk of colorectal adenoma and colorectal cancer

Inflammatory processes, including, specifically, the inflammatory conditions Crohn's disease (CD) and ulcerative colitis (UC) predispose to colorectal cancer. Interleukin-23 is involved in pro-inflammatory signaling; genetic variation in the interleukin-23 receptor (IL23R) has been consistently associated with CD and UC risk. In three case-control studies of colorectal adenoma (n=485 cases/578 controls), colon cancer (n=1424 cases/1780 controls) and rectal cancer (n=583 cases/775 controls), we investigated associations with 18 candidate and tagSNPs in IL23R. The three studies used an identical Illumina GoldenGate assay, allowing thorough investigation across stages and locations of colorectal neoplasia. We further explored associations with molecular cancer subtypes (MSI+, CIMP+, KRAS2mut, TP53mut). In this comprehensive study of genetic variability in IL23R across the spectrum of colorectal carcinogenesis, as well as within colon and rectal tumor molecular subtypes, we observed associations between SNPs in IL23R and risk of rectal cancer: the 88413 C>A (rs10889675) and 69450 C>A (rs7542081) polymorphisms were associated with decreased rectal cancer risk overall (p-trend=0.04 and 0.05 respectively), and specifically with rectal tumors bearing a TP53 mutation (88413 CA/AA vs. CC OR: 0.66; 95% CI: 0.46-94; 69450 CA/AA vs. CC OR: 0.60; 95% CI: 0.37-0.98). However, none of associations remained statistically significant after correction for multiple testing. These data provide some evidence that genetic variability in IL23R may contribute to rectal cancer risk and should be evaluated in additional studies.

Genetic variability in EGFR, Src and HER2 and risk of colorectal adenoma and cancer

The EGFR signaling pathway is involved in carcinogenesis at multiple sites, particularly colorectal cancer, and is a target of colorectal cancer chemotherapy. EGFR signaling is linked to pro-carcinogenic mechanisms, including cell proliferation, survival, angiogenesis, and more recently prostaglandin synthesis. Genetic variability in this pathway has not yet been studied in relation to colorectal carcinogenesis. In three case-control studies of colorectal adenoma (n=485 cases/578 controls), colon cancer (n=1424 cases/1780 controls) and rectal cancer (n=583 cases/775 controls), we investigated associations between candidate SNPs, tagSNPs and haplotypes in EGFR signaling (EGFR, Src, and HER2) and risk. We also examined associations with tumor subtypes: TP53 and KRAS2 mutations, CpG island methylator phenotype, and microsatellite instability. All three studies were genotyped using an identical Illumina GoldenGate assay, allowing thorough investigation of genetic variability across stages and locations of colorectal neoplasia. The EGFR tagSNP 142572T>C (rs3752651) CC genotype was associated with a suggested increased risk for both colon (OR: 1.40; 95% CI: 1.00-1.96; p-trend=0.04) and rectal cancer (OR: 1.39; 95% CI: 0.81-2.41; p-trend=0.65). In tumor subtype analyses, the association was limited to TP53-mutated colon tumors. Using the Chatterjee 1 df Tukey test to assess gene-gene interactions, we observed a statistically significant (p<0.01) interaction between SNPs in EGFR and Src for colorectal adenoma risk. The association with EGFR 142572 should be investigated in additional studies and the significant gene-gene interaction between EGFR and Src in relation to adenoma risk suggests that these two genes are jointly affecting early stages in colorectal carcinogenesis and requires further follow-up.

Genetic variation in inflammatory pathways is related to colorectal cancer survival

PURPOSE

Prognosis of patients with colorectal cancer (CRC) is associated with systemic inflammation, and anti-inflammatory drugs can reduce both CRC incidence and mortality. Genetic variation in proinflammatory pathways can affect an individual's CRC risk. However, few studies have investigated the prognostic importance of this genetic variation in CRC patients.

EXPERIMENTAL DESIGN

We investigated the association between CRC survival and genetic variation in proinflammatory pathways among patients from the Puget Sound Surveillance Epidemiology and End Results registry. Single-nucleotide polymorphisms were genotyped in five genes (PTGS-1, PTGS-2, MRP4, NFκB, and IκBKβ). Vital status was ascertained through linkage to the National Death Index. Cox proportional hazards regression was used to calculate HRs and 95% confidence intervals (CI). The false discovery rate method of Benjamini and Hochberg was applied to address multiple testing.

RESULTS

Four PTGS-1 variants were associated with CRC survival. One, G>A intron 9 (rs1213266), was associated with approximately 50% lower CRC mortality (HR(AA/AG vs. GG) = 0.48; 95% CI, 0.25-0.93). Three variants, including L237M, resulted in significantly elevated CRC mortality risk, with HRs ranging from approximately 1.5 to 2.0. Two variants in IκBKβ, including R526Q, were significantly associated with CRC survival. Correction for multiple testing indicated that variants in both PTGS-1 and IκBKβ are reproducibly associated with CRC survival.

CONCLUSION

Our findings suggest that genetic variation in proinflammatory pathways may be important for CRC prognosis. This investigation represents one of the first descriptions of the relationship between inherited polymorphisms and mortality in CRC patients and provides a starting point for further research.

Abstract A108: Reproductive and hormonal factors in relation to risk of fatal versus non-fatal invasive epithelial ovarian cancer

Ovarian cancer is the fifth leading cause of cancer death for women in the U.S. and the 7th most fatal worldwide. Reproductive and hormonal exposures are known to influence risk of ovarian cancer. We therefore investigated whether these exposures also influence ovarian cancer survival.

We studied survival in relation to hormonal and reproductive history in invasive epithelial ovarian cancer cases and controls from the New England based Case-Control Studies (NECC, 1,642 cases and 2,100 controls). Cases and controls were identified between 1992 and 2008 in New Hampshire and eastern Massachusetts. At the time of enrollment, participants were interviewed in person on a wide range of known and suspected risk factors, including hormone use, childbearing, lifestyle habits and anthropometric characteristics. Polytomous logistic regression was applied to evaluate whether a risk factor was associated differently with fatal (those that died within 3 years of diagnosis) versus non-fatal cases while controlling for other covariates and P-values for heterogeneity (comparing the Odds Ratios (ORs) for fatal ovarian cancer to the ORs for non-fatal ovarian cancer) were calculated based on the maximum likelihood estimates.

A total of 360 of the 1642 women with ovarian cancer (22%) died within 3 years. We found that fatal ovarian cancer was associated with increasing age (multivariate OR 1.05 per 1 year increase in age, 95% CI 1.04 − 1.07, P-value &lt; 0.0001), post-menopausal status (multivariate OR 1.31 vs pre-/dubious menopause, 95% CI 0.97 − 1.77, P-value &lt; 0.0001) and oral contraceptive pill use was consistently more protective across all duration of use categories (P-value = 0.01) as compared with the non-fatal cases. Associations with tubal ligation, total number of ovulatory years, body mass index and family history of breast/ ovarian cancer did not differ significantly between fatal and non-fatal ovarian cancer cases.

These results suggest that the most aggressive subset of invasive epithelial ovarian cancer exhibits important differences in its reproductive and hormonal risk factor profile as compared with non-fatal cases, and that selected protective factors such as oral contraceptive pill use may be especially important for the prevention of the most aggressive subgroup of disease.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):A108.

Body size in early life and adult levels of insulin-like growth factor 1 and insulin-like growth factor binding protein 3

Body size in early life has been associated with breast cancer risk. This may be partly mediated through the insulin-like growth factor (IGF) pathway. The authors assessed whether birth weight, body fatness at ages 5 and 10 years, and body mass index (BMI; weight (kg)/height (m)(2)) at age 18 years were associated with plasma concentrations of insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 in 6,520 women aged 32-70 years at blood draw from the Nurses' Health Study (1990-2006) and Nurses' Health Study II (1997-2005). Birth weight, body fatness in childhood, and BMI at age 18 years were inversely associated with adult IGF-1 levels. For example, IGF-1 levels were 11.9% lower in women who reported being heaviest at age 10 years than in those who were leanest at age 10 (P-trend < 0.0001). Further, women who reported their birth weight as ≥10 pounds (≥4.5 kg) (vs. <5.5 pounds (<2.5 kg)) had 7.9% lower IGF-1 levels (P-trend = 0.002). Women whose BMI at age 18 years was ≥30 (vs. <20) had 14.1% lower IGF-1 levels (P-trend < 0.0001). Similar inverse associations were observed for insulin-like growth factor binding protein 3. These observations did not vary by adult BMI or menopausal status at blood draw. These findings suggest that altered IGF-1 levels in adulthood may be a mechanism through which early-life body size influences subsequent breast cancer risk.

Polymorphisms in WNT6 and WNT10A and colorectal adenoma risk

The WNT/β-catenin signaling pathway upregulates transcription of genes involved in cell proliferation and cancer progression; it has been implicated in colorectal adenoma formation. To date, no studies have examined polymorphisms in WNT genes or WNT gene-environment interactions in relation to adenoma risk. Within a colonoscopy-based case-control study of 628 adenoma cases and 516 polyp-free controls, we analyzed two tagSNPs in WNT6 (rs6747776 G > C, rs6754599 G > C) and WNT10A (rs7349332 G > A, rs10177996 A > G). The WNT6 rs6747776 homozygous minor allele (CC) was associated with increased risk of colorectal adenoma (OR = 2.75, 95% CI: 1.03-7.31). We observed a statistically significant interaction between WNT6 rs6747776 and the proportion of calories from total fat (P-int = 0.02), where the highest risk was observed among those with minor alleles and lowest fat intake. We also detected a marginally significant (0.05 < P ≤ 0.10) interaction with fish intake (P-int = 0.09). Additionally, a marginally significant interaction was observed between proportion of calories from saturated fat and the WNT10A rs7349332 polymorphism. Our results suggest that genetic variability in the WNT pathway may play a role in colorectal adenoma formation or may partly mediate the increased risk of colorectal cancer associated with fat intake.

The After Breast Cancer Pooling Project: rationale, methodology, and breast cancer survivor characteristics

The After Breast Cancer Pooling Project was established to examine the role of physical activity, adiposity, dietary factors, supplement use, and quality of life (QOL) in breast cancer prognosis. This paper presents pooled and harmonized data on post-diagnosis lifestyle factors, clinical prognostic factors, and breast cancer outcomes from four prospective cohorts of breast cancer survivors (three US-based and one from Shanghai, China) for 18,314 invasive breast cancer cases diagnosed between 1976 and 2006. Most participants were diagnosed with stage I-II breast cancer (84.7%). About 60% of breast tumors were estrogen receptor (ER)+/progesterone receptor (PR)+; 21% were ER-/PR-. Among 8,118 participants with information on HER-2 tumor status, 74.8% were HER-2- and 18.5% were HER-2+. At 1-2 years post-diagnosis (on average), 17.9% of participants were obese (BMI ≥ 30 kg/m2), 32.6% were overweight (BMI 25-29 kg/m2), and 59.9% met the 2008 Physical Activity Guidelines for Americans (≥ 2.5 h per week of moderate activity). During follow-up (mean = 8.4 years), 3,736 deaths (2,614 from breast cancer) and 3,564 recurrences have been documented. After accounting for differences in year of diagnosis and timing of post-diagnosis enrollment, five-year overall survival estimates were similar across cohorts. This pooling project of 18,000 breast cancer survivors enables the evaluation of associations of post-diagnosis lifestyle factors, QOL, and breast cancer outcomes with an adequate sample size for investigation of heterogeneity by hormone receptor status and other clinical predictors. The project sets the stage for international collaborations for the investigation of modifiable predictors for breast cancer outcomes.

Genetic variation in C-reactive protein in relation to colon and rectal cancer risk and survival

C-reactive protein (CRP), a biomarker of inflammation, has been shown to be influenced by genetic variation in the CRP gene. In this study, we test the hypothesis that genetic variation in CRP influences both the risk of developing colon and rectal cancer and survival. Two population-based studies of colon cancer (n = 1,574 cases, 1,970 controls) and rectal (n = 791 cases, 999 controls) were conducted. We evaluated four CRP tagSNPs: rs1205 (G > A, 3' UTR); rs1417938 (T > A, intron); rs1800947 (G > C, L184L); and rs3093075 (C > A, 3' flanking). The CRP rs1205 AA genotype was associated with an increased risk of colon cancer (OR 1.3, 95%CI 1.1-1.7), whereas the rs3093075 A allele was associated with a reduced risk of rectal cancer (OR 0.7, 95%CI 0.5-0.9). The strongest association for the rs1205 polymorphism and colon cancer was observed among those with KRAS2 mutations (OR 1.5, 95%CI 1.1-2.0). The CRP rs1205 AA genotype also was associated with an increased risk of CIMP+ rectal tumors (OR 2.5, 95%CI 1.2-5.3); conversely, the rs1417938 A allele was associated with a reduced risk of CIMP+ rectal tumors (OR 0.5, 95%CI 0.3-0.9). We observed interactions between CRP rs1800947 and BMI and family history of CRC in modifying risk of both colon and rectal cancer. These data suggest that genetic variation in the CRP gene influences risk of both colon and rectal cancer development.

Abstract 3761: ALOX5 and FLAP tagSNPs, NSAID use and colorectal neoplasia risk

Introduction: 5-Lipoxygenase-activating protein (FLAP) binds to arachidonic acid (AA) and activates arachidonate 5-lipoxygenase (ALOX5). ALOX5 is upregulated in colon cancer and is involved in the synthesis of leukotriene A4, which plays an important role in immunity and inflammation. ALOX5 also competes with the prostaglandin H synthases PTGS1 and PTGS2, which convert AA into prostaglandins. NSAIDs reduce the risk of colorectal neoplasia and inhibit PTGS1 and PTGS2. We investigated associations between ALOX5 and FLAP and risk of colorectal neoplasia, as well as potential NSAID interactions in three independent study populations that capture the range of colorectal carcinogenesis by including both adenoma and cancer cases.

Methods: A linkage-disequilibrium (LD)-based tagSNP selection algorithm (r2=0.90, MAF=4%) identified 32 tagSNPs in FLAP, representing common genetic variation in Europeans. ALOX5 lacked resequencing data, and we were only able to look at candidate polymorphisms. We used an identical Illumina platform to investigate FLAP SNPs and 1 ALOX5 candidate SNP in three US population-based case-control studies of colon cancer (1424 cases/1780 controls), rectal cancer (583 cases/775 controls), and colorectal adenomas (485 cases/578 controls). VNTR polymorphisms in both genes were also genotyped. Multiple logistic regression analysis was used, adjusting for age, sex, center and restricted to Caucasians (&gt;90% of all study participants). A p value &lt; 0.05 without multiple comparison adjustment was considered statistically significant.

Results: The variant ALOX5 allele of rs4986832 G&gt;A showed a significant trend towards decreased risk of rectal cancer (ORhzv=0.65; 95% CI 0.43-0.98; p-trend=0.04). For FLAP, several SNPs showed increased risk of colorectal neoplasia across all three studies, with the strongest associations for: rs12429692 A&gt;T ORhzv=2.05, 95% CI 1.20-3.53 in adenoma (global p=0.01); rs17239025 G&gt;C ORhet/hzv=1.43, 95% CI 1.01-2.04 in rectal cancer (global p=0.05, p-trend=0.04); rs17222919 A&gt;C ORhzv=1.55, 95% CI 1.00-2.42 in rectal cancer (p-trend=0.05). The inverse association with NSAID use was stronger among those with the wildtype genotype for rs9551960 A&gt;G (rectal cancer p-interaction=0.05) and rs17239025 G&gt;C (colon cancer p-int=0.02), whereas those with variant genotypes had greater NSAID risk reduction of rectal cancer for rs9315053 A&gt;C (p-int=0.03), rs9508832 G&gt;A (p-int=0.02), and rs9506352 G&gt;A (p-int=0.04).

Conclusion: We show evidence that genetic variability in ALOX5 and FLAP may affect risk of colorectal neoplasia. These results suggest that, in ALOX5, rs4986832 is associated with a decreased risk of rectal cancer, whereas FLAP SNPs rs12429692, rs17239025 and rs17222919 increase colorectal neoplasia risk. Additionally, we provide evidence that genetic variability in FLAP may modify the protective association of NSAID use against colorectal neoplasia.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3761. doi:10.1158/1538-7445.AM2011-3761

Abstract 3757: PTGS1 and PTGS2 polymorphisms, fatty acid intake, and risk of colon and rectal cancer

Introduction: Inflammation plays a major role in colorectal cancer. COX-1 and COX-2 convert n-3 and n-6 fatty acids into prostaglandins which have anti- and pro-inflammatory effects, respectively. We examined potential interactions between polymorphisms in PTGS1 (COX-1) and PTGS2 (COX-2) and fat and fatty acid (FA) intake in relation to colon and rectal cancer risk.

Methods: A linkage-disequilibrium-based tagSNP-selection algorithm (r2=0.90, MAF=4%) identified tagSNPs in PTGS1 and PTGS2. We genotyped 16 SNPs in PTGS1 and 17 SNPs in PTGS2 on the same Illumina platform in two independent study populations (colon cancer: 1502 cases, 1862 controls; rectal cancer 713 cases, 914 controls). We investigated potential interactions with intake of total fat, saturated FA (SFA), monounsaturated FA (MUFA), polyunsaturated FA (PUFA), arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) on risk of colon or rectal cancer.

Results: We observed several statistically significant interactions between PTGS1 and PTGS2 genotypes and fat and FA intake (Table). However, few interactions were consistent across fat variables and fell into three general categories of associations: a) individuals with the variant allele and low intake of total fat, SFA, or MUFA were at increased risk for rectal cancer (PTGS1 rs10306122-G, p int=0.01-0.01; PTGS2 rs4648268-A; p int=0.01-0.02); b) individuals with the variant allele and high EPA and DHA intake were less likely to develop colon cancer (PTGS1 rs10306110-G, p int=0.003-0.006); and c) individuals with the wildtype genotype and high EPA and DHA intake had stronger protection from colon cancer (PTGS2 rs4648310-A, p int=0.01-0.05). No interactions were observed for AA.

Conclusion: Our study provides some evidence that genetic variability in PTGS1 and PTGS2 and intake of total fat, SFA, or MUFA and EPA or DHA may interact in causing rectal and colon cancer, respectively.