Medical Bulletin: Breast Implants

The Latest Word from NIH on the Relationship Between Breast Implants and Cancer and Autoimmunity (originally published in "Scleroderma Voice," 2003 #2)

Breast implants were first marketed in the early 1960s, before the 1976 Medical Device Amendments to the Food, Drug and Cosmetic Act required medical devices be shown to be safe and effective.

Since 1962, an estimated 1.5 million to 2.5 million U.S. women have had breast implant surgery.

About 80 percent of breast implants in the United States are for cosmetic reasons, and 20 percent for breast reconstruction after breast cancer surgery.

Although implants were originally assumed to be biologically inactive and therefore safe, many concerns have arisen regarding possible biologic effects.

Most of the concern regarding long-term risks has focused on connective tissue disorders, given a number of anectodal reports of these diseases being diagnosed among women with breast implants.

As a result, Congress charged NIH with conducting a follow-up study to examine the health effects of the implants.

A summary of the scientific studies prior to the NIH study

1. Breast Cancer Risk. The most recent studies, which have been considerably larger than previous studies and have been able to assess long-term risks, do not support the notion that implants are related to breast cancer risk.
2. Connective Tissue Disorders. Anecdotal reports have suggested increased risks of certain connective tissue disorders, including scleroderma, systemic lupus erythematosus, rheumatoid arthritis, and Sjögren's syndrome.

Attempts have been made in a number of epidemiologic studies to assess these relationships. However, given that these are all rare diseases, it has been difficult to draw conclusions regarding whether there are any alterations in risk among breast implant patients.

A large meta-analysis after an Institute of Medicine review of the literature concluded there was not sufficient evidence to support any relationships between breast implants and these disorders.

Format of the NIH Study of Breast Implants

This is one of the longest and largest studies to date on the health effects of breast implants. The participants include 13,500 women who had implant surgery for cosmetic reasons in both breasts before 1989.

Another unique feature of this study is that the investigators compared the breast cancer risks of the implant patients to both the general population and other plastic surgery patients.

Extensive patient data on the potential short-term (rupture) and longer-term complications (cancer, connective tissue diseases, symptoms of connective tissue disease) were also obtained.

Results of the NIH Study

Researchers found no significant increase in breast cancer incidence or mortality among women with implants compared to controls. In fact, a slight decrease in breast cancer risk was found during the initial 10-year follow-up period, perhaps due to medical screening prior to implant surgery.

Patients in the study group experienced lower rates for nearly every cancer and for total mortality when compared to other plastic surgery patients, except for an elevation in the risk of lung and brain cancers, and suicide. While the reasons for these excesses are unclear, it is possible that the higher risks observed are due to chance or to factors common to women who choose to have implants, such as smoking in relation to the lung cancer excess.

The lower overall mortality rates of the implant population support previous findings that people who undergo elective surgery are generally healthier than their peers.

Analyses are currently underway to assess relationships with connective tissue disorders. NCI researchers plan to continue to follow the cohort to update the mortality data over time.