Augmentation mammaplasty and breast cancer: a 5-year update of the Los Angeles study.

We have previously reported on the risk of breast cancer in women during the first few years following cosmetic augmentation mammaplasty and are now presenting results after longer exposure. Long-term carcinogenicity of breast implants in humans has not been assessed previously. We conducted a retrospective cohort study of 3112 patients with a median of 10.6 years of postimplant experience (range 0.1 to 31.7 years). Patients were enrolled from surgeons' records, and cancer outcomes were monitored by the population-based cancer registry serving Los Angeles County. Because of confidentiality concerns, there was no direct patient contact. Twenty-one breast cancers were observed among the implant patients as compared with 31.7 expected, based on Los Angeles County incidence rates [standardized incidence ratio (SIR) = 66 percent, 95 percent confidence limits (CL): 41 percent, 101 percent]. For all other malignancies combined, 45 were observed and 50.0 were expected (SIR = 90 percent, CL: 66 percent, 120 percent). Although the numbers of cases were very small, increased frequencies of lung and vulvar cancers were observed. Based on the evidence to date, we conclude that there is no increase in breast cancer incidence following augmentation mammaplasty.