Polymorphisms modify breast cancer risk in smokers.Previous research has established cigarette smoking as a risk factor for a number of cancers, including those of the lung, pancreas, and head and neck. A link between cigarette smoking and breast cancer is not as clear; however, scientists do know that breast cancer occurs at different rates in different racial groups. In this paper, NIEHS NIEHS National Institute of Environmental Health Sciences (NIH, DHHS) grantee An individual to whom a transfer or conveyance of property is made. In a case involving the sale of land, the buyer is commonly known as the grantee. grantee n. Robert C. Millikan of the University of North Carolina at Chapel Hill The University of North Carolina at Chapel Hill is a public, coeducational, research university located in Chapel Hill, North Carolina, United States. Also known as The University of North Carolina, Carolina, North Carolina, or simply UNC and his colleagues document findings suggesting that specific combinations of polymorphisms on certain nucleotide excision repair Nucleotide excision repair is a DNA repair mechanism. DNA constantly requires repair due to damage that can occur to bases from a vast variety of sources including chemicals but also ultraviolet (UV) light from the sun. (NER) genes may modify the risk of breast cancer in black women who smoke. NER is the primary means by which smoking-induced DNA DNA: see nucleic acid. DNA or deoxyribonucleic acid One of two types of nucleic acid (the other is RNA); a complex organic compound found in all living cells and many viruses. It is the chemical substance of genes. damage is repaired. There are several known polymorphisms on genes involved in NER. These investigators conducted a genetic epidemiologic study epidemiologic study A study that compares 2 groups of people who are alike except for one factor, such as exposure to a chemical or the presence of a health effect; the investigators try to determine if any factor is associated with the health effect aimed at determining whether such polymorphisms alter the association between smoking and breast cancer. The investigators analyzed exposure histories and DNA samples extracted from peripheral blood lymphocytes Peripheral Blood Lymphocytes (PBL): These are the mature lymphocytes (small white immune cells) that are found circulating in the blood, as opposed to organs, such as the lymph nodes, spleen, thymus, liver or bone marrow. These cells consist of T cells, NK cells and B cells. of 3,863 women (1,449 black, 2,414 white) aged 21 to 74. The women were participating in the Carolina Breast Cancer Study, a large population-based case-control study of breast cancer in North Carolina. Next the investigators calculated odds ratios for breast cancer and smoking and for breast cancer and nine polymorphisms on six NER genes. Then they examined how odds ratios for smoking were modified by single and combined NER genotypes. In general, they found, smoking was more strongly associated with breast cancer in black women than in white women. The association increased even more for black women with particular patterns of polymorphisms when combined with different smoking characteristics including amount of smoking, duration, time since smoking cessation, age at smoking initiation, and being a former smoker. No interactions were seen in white women. The investigators believe this is the first study to examine multiple NER polymorphisms together as susceptibility factors for breast cancer in combination with smoking. Further studies with larger numbers of participants are needed to confirm these results. Mechanic LE, Millikan RC, Player J, de Cotret AR, Winkel S, Worley K, et al. 2006. Polymorphisms in nucleotide excision repair genes, smoking and breast cancer in African Americans and whites: a population-based case-control study. Carcinogenesis car·ci·no·gen·e·sis n. The production of cancer. carcinogenesis production of cancer. biological carcinogenesis viruses and some parasites are capable of initiating neoplasia. 27:1377-1385. |
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