Bethesda, Md. — Women with cosmetic breast implants are not at an increased risk of death from breast cancer, but that they do have an excess risk of suicide, according to results from a recent update to a previously published retrospective cohort study examining mortality associated with augmentation mammoplasty.
In an article published in March this year (Epidemiology. 2006;17:162-169), Louise A. Brinton, Ph.D., and coauthors analyzed outcomes based on mortality data from five additional years of follow-up. They calculated relative risks (RR) of mortality from various causes among 12,144 implant recipients compared with a control group of 3,614 patients who had undergone other types of plastic surgery procedures.
In addition, standardized mortality ratios (SMR) were computed using the general population of U.S. females as the reference group.The key findings showed:
As a new finding, the present analysis also found the breast implant recipients had an approximate 75 percent increased risk of death from motor vehicle accidents compared with other plastic surgery patients, Dr. Brinton reports.
"These updated findings are fairly reassuring regarding the overall risks of death from various types of cancer, and the continued absence of an excess risk of breast cancer mortality is especially important considering information that implants can interfere with the detection of breast lesions and thereby might delay diagnosis. However, we continue to be concerned about the excess risk of deaths from suicide that has now been confirmed in several other studies," says Dr. Brinton, chief of the hormonal and reproductive epidemiology branch, National Cancer Institute, National Institutes of Health, Bethesda, Md.
Dr. Brinton points out that one of the strengths of the design of the mortality risk study is that the breast implant group is not a selected series but rather a complete enumeration of a large number of consecutive patients who received implants at 18 different plastic surgery sites representing six geographic areas.
"Through linking against the national death index, we were able to get a complete enumeration of mortality, and so the results of this study are not subject to confounding by reporting biases that can occur when data collection depends on patient self-reports of disease development," Dr. Brinton says.
Comparison to control
The comparison to a plastic surgery control group is also considered one of the study's strengths.
"We believe our choice of a comparison group is important because of the likelihood that cosmetic breast implant patients and other plastic surgery patients are likely to share common lifestyle characteristics," Dr. Brinton explains.
Discussing some of the specific findings in more detail, Dr. Brinton notes that during the extra five years of follow-up, there were no additional deaths due to brain cancer among the implant patients. As a result, both the standardized mortality ratio and relative risks decreased in the breast implant group. While the excess risk of death from respiratory cancer remained, it did not appear to be attributable to higher rates of smoking, given that previous analyses had shown no difference in smoking behavior between the implant and the comparison patients in the study. Notably as well, the risk did not increase with lengthening follow-up.
"That lack of an increase could be used to support an argument that the association detected is not causal," Dr. Brinton says. The persisting increased risk of death from suicide and the newly found increased risk of death from motor vehicle accidents are worrisome.
"Our study also showed an excess risk of death relating to drug and alcohol dependency. Although the numbers were small, that information suggests some of the motor vehicle accidents night not have been purely accidental."
The reasons for the increased risk of suicide among the breast implant recipients are unclear, but have been suggested to relate to personality characteristics as well as post-implantation dissatisfaction.