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.