NCI Study Finds No Conclusive Evidence that Breast Implants Affect Development of Connective Tissue Disorders*
Researchers at the National Cancer Institute (NCI), part of the
National Institutes of Health, found no convincing evidence that
breast implants have an effect on the development of subsequent
connective tissue disorders (CTDs). The results are reported in
the October 1, 2004 issue of the American Journal of Epidemiology.*
The researchers used data from one of the largest studies on the
long-term health effects of breast implants. A large number of patients
reported CTDs, but when their records were examined by two board-certified
rheumatologists, few cases were considered likely.
In 1992, the U.S. Congress asked the National Institutes of Health to investigate
the long-term safety of breast implants. Scientists at NCI, led
by Louise Brinton, Ph.D. in the Division of Cancer Epidemiology
and Genetics, examined the medical records of 13,500 women who had
cosmetic breast implant surgery before 1989 and 4,000 women similar
in age who had other types of plastic surgery. Although it was not
the original intent of the study, the available information provided
investigators with an opportunity to study the risk of CTDs in this
For some time, there has been uncertainty regarding
whether breast implants might be associated with the development
of certain CTDs. Most of the previous studies on this issue had
small sample sizes, limited time to follow the clinical outcomes
of the women after their surgeries, and imprecise information on
either implant status or disease outcomes. This study included a
large population of women with breast implants, detailed information
on their implants, patients' answers to questions about their disease
experience and other health characteristics, and long-term follow-up
of up to 13 years.
Four major CTDs (rheumatoid arthritis, systemic lupus erythematosus,
scleroderma, and Sjögren's syndrome) were more commonly reported
by breast implant patients, with an approximate two-fold increase
in risk. Attempts were made to review the medical records for three
of these conditions where there were elevations in reported risks
both before and after 1992, the time when breast implants were deemed
investigational by the U.S. Food and Drug Administration. Only 30
percent to 40 percent of the medical records could be obtained.
When these records were blindly reviewed by two expert rheumatologists,
only 17 percent to 30 percent of the diagnoses were considered 'likely.'
When only likely diagnoses were considered, the excess risk of CTDs
became statistically non-significant, meaning they could have happened
by chance. Further, the small number of confirmed cases of scleroderma
and Sjogren's syndrome made interpretation of the risks difficult.
The researchers also were unable to assess the existence of any
new CTD specific to implant patients.
To further clarify the relationship of implants to the risk of
CTDs, future research should include clinical examinations of patients
using defined diagnostic criteria for these disorders. Given the
rarity of conditions such as scleroderma and Sjögren's
syndrome, a study would need to be very large to fully clarify the
association between breast implants and these disorders.
For more information about cancer, visit the NCI Web site at http://www.cancer.gov
or call NCI's Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).
*Brinton LA, Buckley LM, Dvorkina O, et
al. Risk of Connective tissue disorders among breast implant patients.
Am J Epidemiology, Oct 2004; 160. (Released online September 21, 2004)
*Note: This press release was originally posted as "NCI Study Finds No Long-term Health Effects from Breast Implants," but has been amended. This new title more closely reflects the main focus of the release -- the specific relationship between breast implants and the risk of connective tissue disorders (CTDs).