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Tonsillectomy may increase breast cancer risk
By LOIS BAKER
Contributing Editor
Women who had their tonsils removed in childhood may be at increased risk of developing premenopausal breast cancer, a study conducted by UB epidemiologists has found.
Results showed that premenopausal women in the study who had a tonsillectomy as children were 50 percent more likely to develop breast cancer than women who had not had a tonsillectomy. No increased risk was observed in postmenopausal women who had undergone the procedure.
The findings were reported Sunday at the American Association of Cancer Research annual meeting in Los Angeles. Theodore Brasky, a doctoral student in the Department of Social and Preventive Medicine, School of Public Health and Health Professions, was lead researcher.
"Previous epidemiologic studies have found that tonsillectomy is associated with an increased risk of Hodgkin's lymphoma, leukemia and cancers of the breast and prostate," said Brasky. "Our study adds to the evidence that tonsillectomy is associated with cancer risk. However, the evidence is still preliminary, and it isn't possible to say that there is a causal link.
"The apparent association may be related to the loss of the protective function of the tonsils when they are removed," said Brasky. "An alternate theory is that tonsils that need to be removed may be markers for severe or chronic infections in childhood. These infections cause inflammation, and chronic inflammation may contribute to carcinogenesis."
The research is based on data from the Western New York Diet Study, a case-control study conducted between 1986-91 that collected extensive information from women on diet and disease. The 740 breast cancer cases came from hospitals throughout Erie and Niagara counties. The 810 controls were selected randomly from motor vehicle records for women under 65 and from Medicare rolls for women 65 and older.
"The differences in associations for pre- and postmenopausal breast cancer may indicate that breast cancer in these two age groups may be caused by different factors," said Brasky. "It's also possible that the reason tonsils are removed has changed over time, and that may explain the differences seen between pre- and postmenopausal women in this study."
The finding among premenopausal women contributes to the accumulating evidence that childhood exposures influence the risk of breast cancer in adulthood, Brasky noted. However, because the findings are among only a few studies that have investigated the association of tonsillectomy and breast cancer, they should be interpreted with caution until they are replicated, he said.
Also contributing to the study were Matthew Bonner, Saxon Graham, John Vena, James Marshall, John Brasure and Jo Freudenheim, all current or former members of the Department of Social and Preventive Medicine.
The work was supported by grants from the National Cancer Institute and the American Cancer Society.