BUFFALO, N.Y. -- The answer to the question of whether smoking increases a women's risk of developing breast cancer may lie in her genes, researchers at the University at Buffalo and the National Cancer Institute have found.
Results of their study, the first to consider genetic variability as a factor in a person's breast-cancer susceptibility to the carcinogens in cigarette smoke, will be published in the Nov. 13 issue of the Journal of the American Medical Association.
The results showed that postmenopausal women born with the slow-acting gene for N-acetyltransferase (NAT2), an enzyme known to detoxify carcinogenic compounds in cigarette smoke, and who smoked more than a pack of cigarettes a day 20 years before diagnosis, had seven times the risk of developing breast cancer than women born with the fast-acting gene.
The risk was highest for women who began smoking before the age of 18.
The two genotypes are referred to as slow or fast acetylators. No relationship was found between genotypes and risk of breast cancer among premenopausal women who smoked.
Christine Ambrosone, Ph.D., who conducted the research while a post-doctoral fellow in the UB Department of Social and Preventive Medicine, said the findings provide new insight into why previous epidemiologic studies may have failed to show a consistent association between cigarette smoking and breast cancer, when the association is clear in many other organs.
"These findings on breast cancer require substantial replication, but the potential implications may be important," said Ambrosone, now a research epidemiologist at the National Center for Toxicological Research in Arkansas.
"If further investigations in other study populations reveal similar associations between NAT2 genotype, cigarette smoking and breast-cancer risk, it would be an important insight into the etiology of this disease," she added. "It is one more cancer site in wh
Contact: Lois Baker
University at Buffalo