Epidemiologic follow-up studies of breast augmentation patients.

Although hundreds of thousands of women in this country have had augmentation mammaplasty, little is known about long-term effects. Clinical studies have documented a decreased ability to detect breast lesions in women with implants, leading to concerns regarding breast cancer risk. There is also anecdotal evidence that implants might have effects on a variety of immune conditions. More recently, concern over carcinogenic effects has heightened given findings that the polyurethane foam, used in a minority of implants to envelope silicone gel, contains chemicals linked to cancer in laboratory animals. Only a few epidemiologic studies on long-term effects have been published, and all have had methodologic limitations, including the possibility of inappropriate comparison rates, limited and/or incomplete follow-up, absence of information on patients characteristics, and lack of specific information on types of implanted material. Several case-control and cohort studies are currently underway which are attempting to overcome methodologic limitations of previous studies. Past descriptive and analytic studies are reviewed. In addition, ongoing follow-up efforts are discussed, with attention given to the methodologic adjuncts necessary for allowing valid assessments of long-term disease effects.