Silicone breast implants and risk of cancer?

ABSTRACT To the Editor. —We examined cancer risk following breast implant surgery in Sweden by use of a nationwide linked registry. The registry combines individual hospital discharge information with subsequent cancer incidence. The methods of this linked-registry approach have been reported in a study that evaluated cancer risk associated with discharge diagnoses.1 We identified 1756 Swedish women who received breast implants for nonmedical (cosmetic) reasons during the period 1965 through 1983. The patients were followed up for cancer occurrence through 1989. They contributed 20610 person-years of experience, with an average duration of 11.7 years since implant. We analyzed all major cancer sites, using national Swedish incidence rates to calculate expected numbers. In all, 34 cases of cancer were identified during the study period compared with 33.7 expected cases (standardized incidence ratio [SIR], 1.01; 95% confidence interval [CI], 0.7 to 1.4). No cancers were observed in the first year of follow-up.