Review of Methods in “Breast Augmentation: A Risk Factor for Breast Cancer?”

To the Editor: We are writing to follow up on the article by Berkel et al. concerning breast implants and the risk of cancer (June 18, 1992, issue).1 The study was a population-based, noncurrent cohort-linkage study, which was performed under the auspices of the Alberta Cancer Board. Essentially, the study was designed to identify women who had undergone cosmetic breast augmentation between 1973 and 1986 and to link this cohort of women with the Alberta Cancer Registry to determine which women with implants subsequently had breast cancer. The actual breast-cancer rates were compared with the expected rates, which were calculated . . .