Current issues of ACP Journal Club are published in Annals of Internal Medicine


Etiology

Review: Insufficient information exists about the overall health risk associated with silicone gel breast implants

ACP J Club. 1996 July-Aug;125:21. doi:10.7326/ACPJC-1996-125-1-021


Source Citation

Silverman BG, Brown SL, Bright RA, et al. Reported complications of silicone gel breast implants: an epidemiologic review. Ann Intern Med. 1996 Apr 15;124:744-56.


Abstract

Objective

To review the most common local and systemic complications associated with silicone gel breast implants.

Data sources

Studies were identified by searching the MEDLINE database (1975 to 1995) and by reviewing the literature.

Study selection

Only epidemiologic studies with cohort, case-control, or cross-sectional designs were selected. Case series were reviewed when epidemiologic studies were unavailable (as for estimates of local complications).

Data extraction

Data were extracted on study design, sample size and selection, determination of exposure and outcome variables, and duration of follow-up. Studies were evaluated for methodologic quality.

Main results

The epidemiologic research on breast implants has primarily focused on the potential for systemic complications, particularly cancer and connective tissue disease. The results of several large epidemiologic studies have shown no greatly increased short-term risk for defined, physician-diagnosed scleroderma or other connective tissue diseases or for breast cancer in association with silicone breast implants. Most studies have focused on well-defined connective tissue diseases and, therefore, cannot rule out the possibility of an elevated risk for 1 or more atypical connective tissue disease-like syndromes that do not meet the standardized diagnostic criteria used in most studies. The risk for breast cancer in women with implants as they reach the postmenopausal years is not known. No epidemiologic study has examined local complications of breast implantation, such as rupture, capsular contracture, and breast pain. Research to date, based primarily on case series, is insufficient to accurately determine either the incidence rates of local complications of breast implants or the proportion of implant recipients for whom explantation will be required to treat these conditions. Published studies of implant failure have suggested a prevalence of failure ranging from 5% to 70%. The most recent case series reports suggest that aging of the implant is an important factor in rupture.

Conclusions

Epidemiologic studies of scleroderma and other defined connective tissue diseases and of breast cancer suggest that recipients of silicone gel breast implants have no substantially increased risk for these disorders. The epidemiologic literature is insufficient to rule out an association between breast implants and connective tissue disease-like syndromes and the risk for breast cancer in postmenopausal women. Estimates of the true incidence of local complications are unavailable.

Source of funding: No external funding.*

For article reprint: Dr. B.G. Silverman, Center for Devices and Radiological Health, HFZ-541, U.S. Food and Drug Administration, 1350 Piccard Drive, Rockville, MD 20850, USA.

*Information provided by author.


Commentary

The media and legal frenzy surrounding the breast implant controversy has confused the public and has left practicing physicians at a loss about how best to advise their patients about implants. In this review, a group of scientists from the Food and Drug Administration in the United States summarized published reports of the complications of silicone breast implants. Critical appraisal of this overview (1) indicates a number of limitations. First, the patients' exposures and outcomes of interest were not specified in the criteria used to select studies for the review. Second, methodologic standards were not used to select studies, only one database was searched, no personal contact with experts in the area was made, and publication bias was not addressed. Third, explicit assessments of the validity of the included studies were not done.

These limitations notwithstanding, the main contribution of this overview is that it provides the practicing clinician with 2 clear and accurate messages that they can confidently convey to their patients about the complications of breast implants. First, all the scientific evidence published to date consistently shows that breast implants do not substantially increase the risk for connective tissue disorders or breast cancer; and, second, estimates of the true incidence of local complications, which are crucial to determine implant safety, are completely lacking.

Although food, drug, and cosmetic products have been subject to government regulation for centuries, medical devices have only recently been recognized as a distinct category of health products requiring regulation (2). These historical differences in government regulation of devices compared with drugs have contributed to the troublesome paucity of safety data, which continues to fuel the breast implant controversy.

Sherine E. Gabriel, MD, MSc
Mayo ClinicRochester, Minnesota, USA


References

1. Oxman AD, Cook DJ, Guyatt GH. Users' guides to the medical literature. VI. How to use an overview. JAMA. 1994; 272:1367-71.

2. Hutt PB. A history of government regulation of adulteration and misbranding of medical devices. Food Drug Cosmetic Law Journal. 1989;44:99-117.