Association between CYP17 gene polymorphism and risk of breast cancer in young women.
Long-term exposure to oestrogens is a well-recognised risk factor for breast cancer, whereas little is known about the influence of polymorphisms of genes involved in oestrogen biosynthesis and metabolism. A candidate, containing a single bp polymorphism, T-->C, (designated, A2 allele), might be the CYP17 gene, which codes for an enzyme involved in oestrogen synthesis. This polymorphism creates an additional Sp1-type promoter site (CCACC box), which has been shown to be associated with increased serum oestrogen levels. We performed a case-control study, to evaluate association of the CYP17 gene polymorphism with risk of breast cancer in young women (younger than 37 years). We found a statistically significant increased risk in carriers of at least 1 A2 allele [odds ratio (OR), 2.0; 95% confidence interval (CI), 1.1-3.5, p = 0.027], and a trend toward a gene-dose effect illustrated by a slightly higher risk for A2-homozygous subjects (OR, 2.8) than for heterozygous women (OR, 1. 9). Furthermore, when we investigated the CYP17 genotype in relation to tumour characteristics, breast cancer patients with 1 or 2 A2 alleles tended to have lower oestrogen receptor levels (risk ratio, 0.70; CI, 0.41-1.2, p = 0.44). Our findings suggest that CYP17 gene polymorphism influences breast carcinogenesis in young women. Int. J. Cancer (Pred. Oncol.) 84:350-353, 1999.
Department of Biomedicine and Surgery, Division of Oncology, Faculty of Health Sciences, University Hospital, Linköping, Sweden.
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Bergman-Jungeström
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Gentile
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Lundin
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Wingren
D000328:Adult; D000367:Age Factors; D000483:Alleles; D001483:Base Sequence; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D002453:Cell Cycle; D016001:Confidence Intervals; D005260:Female; D006580:Genetic Carrier Screening; D006801:Humans; D008207:Lymphatic Metastasis; D016017:Odds Ratio; D017354:Point Mutation; D011110:Polymorphism, Genetic; D011237:Predictive Value of Tests; D011401:Promoter Regions, Genetic; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D012307:Risk Factors; D013254:Steroid 17-alpha-Hydroxylase / Q000235:genetics*; D016019:Survival Analysis; D013548:Sweden / Q000453:epidemiology
D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D013254:Steroid 17-alpha-Hydroxylase