WASHINGTONAn extensive review of the medical literature finds
that women with silicone breast implants are no more likely to
develop cancer and several other major ailments than women in the
general population. The new report by the Institute of Medicine (IOM)
concludes, however, that implants commonly lead to often-painful
complications that may require surgery or other treatment.
Based on all the evidence, we determined that the primary
safety concern associated with breast implants is local complications
resulting in pain, disfigurement, infections, and other medical
problems, said Stuart Bondurant, MD, who chaired the committee
that prepared the report. We could find no definite evidence
linking breast implants to cancer, immunologic diseases, neurologic
problems, or other systemic diseases.
The Department of Health and Human Services funded the report,
Safety of Silicone Breast Implants, as directed by
To complete its report, the committee evaluated more than 3,000
publications, including some 2,000 peer-reviewed articles. It is the
third by a scientific panel to conclude that current evidence does
not support a causal link between silicone breast implants and
serious diseases such as cancer. The others were done by the UKs
Independent Review Group, released in 1998, and the National Science
Panel, appointed by federal judge Sam C. Pointer, Jr., who is
handling the lawsuits against implant makers that have been
consolidated by the federal courts.
The issue of breast implants has been a contentious and controversial
one for years. The IOM excluded anyone from its committee who
had participated in studies of breast implants, whose associations or
prior statements might bias the results, who was involved with
implant makers or relevant ongoing legal matters, or who had
conflicts of interest, said Dr. Bondurant, professor of
medicine and dean emeritus of the University of North Carolina School
Problems With Mammograms
The IOM panel cautioned that implants can make it harder to detect
breast cancer on mammograms by obscuring a variable part of the
breast tissue, distorting breast architecture, and especially in the
presence of firm contractures, making a proper examination with
proper compression of the breast more difficult and occasionally impossible.
The committee also concluded that there is no evidence that mothers
with implants pass on silicone to their infants when breast-feeding.
Indeed, the panel noted, higher levels of silicon, the parent element
of silicone, have been detected in cows milk and commercial
baby formula than in the milk of nursing mothers with implants.
As for the relatively common local complications, such as implant
rupture, contraction, and deflation, the panel found it difficult
to come up with a precise estimate of the frequencies of these
outcomes in the absence of large, long-term, systematic follow-up
studies, said vice chair Virginia L. Ernster, PhD, of the
University of California, San Francisco.
In its section on cancer, the panel concluded that the available
evidence fails to support an association of silicone or silicone
breast implants with experimental carcinogenesis (other than rodent
solid-state carcinogenesis), primary, or recurrent breast cancer,
breast sarcoma, or other solid tumors, lymphoma, or myeloma.
If anything, evidence (though limited) suggests a lower risk of
breast cancer in women with silicone breast implants, the
report said. At a press conference, Dr. Bondurant hastened to
emphasize that the report did not mean to imply any protective effect
of silicone implants.
The panels review also failed to substantiate reported links
between implants and a recurrence of breast cancer or an association
with increased risk of sarcomas, monoclonal gammopathy of
undetermined significance, and immunoglobulin G myeloma.