CASP8 polymorphisms, estrogen and progesterone receptor status, and breast cancer risk

Objectives This study was conducted to evaluate the potential role of CASP8 genetic polymorphisms in the etiology of breast cancer in a case-control study, Korea. Methods Incident breast cancer cases confirmed histologically (n = 1,599) were recruited from two hospitals in Seoul during 2001-2005. Control subjects (n = 1,536) were selected from the Health Examinee Cohort from Seoul and Gyeonggi Province surrounding Seoul, Korea. Three SNPs (D302H D > H, 5'-UTR C > T, and K337K G > A) were genotyped by the primer extension assay. The CASP8 D302H, which was not polymorphic in 48 samples, was excluded in further genotyping. Odds ratios and 95% confidential intervals (95% CIs) were estimated by unconditional logistic regression model adjusted for age at enrollment, education, age at first full-term pregnancy, cigarette smoking, and family history of breast cancer. Results The 5'-UTR T allele containing genotypes (CT/TT) were associated with an increased risk of breast cancer, compared with those with the CC genotype (OR = 1.13, 95% CI = 0.95-1.34; and OR = 1.48, 95% CI = 1.04-2.10, respectively; P-trend = 0.02). When stratified by the estrogen and progesterone receptor status, the association between the 5'-UTR T allele and breast cancer risk was prominent in ER(+) and PR(+) cases among pre-menopausal women (OR = 1.31, 95% CI = 1.00-1.72 and OR = 1.40, 95% CI = 1.06-1.85, respectively), whereas the association was found prominent in ER(-) or PR(-) cases (OR = 1.32, 95% CI = 0.93-1.87 and OR = 1.42, 95% CI = 1.04-1.94, respectively) among post-menopausal women. Conclusion Our results thus suggest that the CASP8 5'-UTR C > T are associated with breast cancer risks and the effect may be modified by estrogen and progesterone receptor status.