Sir:FigureThe Los Angeles Augmentation Mammaplasty study, a cohort of cosmetic breast implant patients, was initiated in 1977. Methods and cancer incidence results have been published periodically, most recently in 2007.1 We now update this cohort with another 12 years of follow-up data. The cohort comprises white female residents of Los Angeles County, California, who underwent implantation between 1953 and 1980, with a total of 52,957 person-years from the date of implantation through 2006. The maximum length of follow-up is 35 years (median, 17.7 years). Incident cancer cases have been detected through record linkage with the population-based cancer registry for Los Angeles County. The cancer incidence among cohort members is shown in Table 1, including the number of incident cancers observed, the number of cancers expected, the standardized incidence ratio, and the 95 percent confidence interval.Table 1: Numbers of Observed and Expected Cancers, Standardized Incidence Ratios, and 95 Percent Confidence Intervals by Cancer Site, Los Angeles Augmentation Mammaplasty Study, 1972 to 2006The risk of breast cancer continues to be significantly lower than expected, consistent with other studies. A pooled analysis of Swedish and Danish cohorts yielded a standardized incidence ratio of 0.73 (95 percent confidence interval, 0.58 to 0.90).2 A Canadian cohort reported a standardized incidence ratio of 0.75 (95 percent confidence interval, 0.70 to 0.81),3 Finnish researchers reported a standardized incidence ratio of 0.5 (95 percent confidence interval, 0.2 to 1.0),4 and a U.S. study found a standardized incidence ratio of 0.89 (95 percent confidence interval, 0.8 to 1.1).5 Cancer of the lung and bronchus and in situ vulvar cancer continue to be significantly elevated. Those findings are not consistently replicated in other studies and may reflect local lifestyle factors such as smoking prevalence and number of sexual partners. Cosmetic breast implants are not associated with an increased risk of breast cancer. In fact, in this cohort, breast implant patients have continuously experienced significantly less breast cancer than expected. Dennis M. Deapen, Dr.P.H. Garry S. Brody, M.D. Department of Preventive Medicine and, Division of Plastic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, Los Angeles, Calif. ACKNOWLEDGMENTS Funding was provided by the National Endowment for Plastic Surgery. The collection of cancer incidence data used in this study was supported by the California Department of Public Health as part of the statewide cancer reporting program mandated by California Health and Safety Code Section 103885; the National Cancer Institute's Surveillance, Epidemiology, and End Results Program under contract N01-PC-35136 awarded to the Northern California Cancer Center; contract HHSN261201000035C awarded to the University of Southern California, and contract N01-PC-54404 awarded to the Public Health Institute; and the Centers for Disease Control and Prevention's National Program of Cancer Registries, under agreement no. 1U58 DP000807-01 awarded to the Public Health Institute. DISCLOSURE Dr. Deapen has no financial interest in any product mentioned in this article. He has consulted on epidemiologic research for breast implant manufacturers. Dr. Brody has been a consultant in the past to Dow Corning Corp. and Mentor Corp. DISCLAIMER The ideas and opinions expressed in this communication are those of the author(s) and endorsement by the State of California Department of Public Health, the National Cancer Institute, and the Centers for Disease Control and Prevention or their contractors and subcontractors is not intended nor should be inferred.