Women with Silicone Breast Implants Have No Increased Risk of Death from Most Causes
In one of the largest studies on the long-term health effects of silicone breast implants, researchers from the National Cancer Institute (NCI) in Bethesda, Md., found that women with implants were not at increased risk for most causes of death compared to the control group. The exceptions were deaths from suicide, and brain and respiratory cancers. The significance of the increased cancer risks is not clear.
The study, published in the May issue of Epidemiology*, is the first to look at all causes of mortality of breast implant patients. Previous reports have limited their analyses to mortality from breast cancer and found, as in this report, no increased risk in breast cancer mortality for implant patients compared to the general population.
The participants in the current study were from 18 plastic surgery practices and included 13,500 women who had implant surgery for cosmetic reasons and, for comparison, 4,000 women similar in age who had some other type of plastic surgery, such as removal of fat from the stomach or wrinkles from the face or neck. The average length of follow-up was 13 years. The researchers compared all causes of mortality of the implant patients to two separate control groups: the general population and the 4,000 plastic surgery patients.
Compared to the general population, they found that nearly every cause of death including all cancers, circulatory and digestive system diseases, endocrine, nutritional, metabolic and immune diseases, and cirrhosis of the liver was decreased among implant patients. The lower mortality rates of the implant population support previous findings that people who undergo elective surgery are generally healthier than their peers in the general population. The lower rates are due primarily to fewer deaths from cancers and diseases of the circulatory system, the most common causes of death in the general population.
The exceptions to the lower rates were deaths from brain cancer, suicide, pneumonia and emphysema. Breast implant patients were two to three times more likely to die from brain cancer, and nearly twice as likely to die from suicide, pneumonia, and emphysema, compared to the general population. The researchers also found, after 15 or more years of follow-up, an increased risk of respiratory tract cancer among implant patients.
The implant patients, however, did not have higher mortality rates from diseases that have been tentatively linked to silicone exposure. These include cancers such as sarcoma and multiple myeloma, as well as a variety of connective tissue disorders scleroderma, Sjorgrens disease and lupus erythematosus.
The scientists also looked to see if there were mortality differences among the implant patients related to the calendar year of the implant, the woman's age at the time of surgery, or the type of implant. One significant finding was that women who were age 40 or older at the time of surgery had a two- to three-fold increased risk from suicide 10 or more years later.
The authors previously showed that other plastic surgery patients may be a more appropriate comparison group than women in the general population for studies of the health effects of breast implants because of certain similarities between the two groups of patients. These include the number of pregnancies, previous gynecologic operations, and operations for benign breast disease, levels of alcohol consumption, and rates of cigarette smoking.**
Although both plastic surgery groups have lower mortality rates than the general population, women with breast implants have slightly higher overall mortality rates than other plastic surgery patients. Specifically, the researchers found that implant patients were three times more likely to die from respiratory tract cancer, two to three times more likely to die from brain cancer, and four to five times more likely to die from suicide.
The reason for the increase in respiratory tract cancers is not clear. There is not enough information to evaluate whether this increase may be related to silicone exposure or to higher smoking rates among implant patients. The vast majority of women with respiratory cancers were not alive at the time of the study. Therefore, lifestyle information obtained from questionnaires sent to living participants was not available. However, the surviving implant patients do not have higher smoking rates than the other plastic surgery patients.
Likewise, the reasons for the higher rate of brain cancer are not clear. There have been suggestions that implants may have an effect on neurologic pathways, but the data on this association are not consistent. It is possible that the higher risks observed for both brain and respiratory cancers are not related to exposure to silicone, but are due to either chance findings or to factors common to women who choose to have implants.
The higher suicide rates of the implant patients correlate with characteristics described among implant patients in previous reports marital difficulties, depression, emotional disorders, and low self-esteem.
It is estimated that between 1.5 million and 2 million U.S. women have had breast implants since they first appeared on the market in 1962. About 80 percent are for cosmetic reasons and 20 percent for breast reconstruction after breast cancer surgery. The current study does not include patients who received implants following a diagnosis of breast cancer.
In a previous analysis of the data published last year in Cancer Causes and Control***, the authors found no association between breast implants and the subsequent risk of breast cancer. A second report showed that risks for most other cancers among implant patients were not increased, with the exception of brain and respiratory cancers.****
Future analyses will evaluate the risk of connective tissue disorders
<*>The study is titled: "Mortality Among Augmentation Mammoplasty Patients." The authors are Louise A. Brinton, Jay H. Lubin, Mary Cay Burich, Theodore Colton, Robert N. Hoover. Epidemiology, May 2001;12(3):321-326.
<**>The study is titled: "Characteristics of a Population of Women with Breast Implants Compared with Women Seeking Other Types of Plastic Surgery." The authors are Louise A. Brinton, S. Lori Brown, Theodore Colton, Mary Cay Burich, and Jay H. Lubin. Plastic and Reconstructive Surgery 2000;105(3):919-27.
<***>The study is titled, "Breast Cancer Following Augmentation Mammoplasty (United States)." The authors are Louise A. Brinton, Jay H. Lubin, Mary Cay Burich, Theodore Colton, S. Lori Bown, and Robert N. Hoover. Cancer Causes and Control 2000; Vol. 11(9):819-827
<****>The study is titled, "Cancer Risk at Sites Other than Breast Following Augmentation Mammoplasty." The authors are Louise A. Brinton, Jay H. Lubin, Mary Cay Burich, Theodore Colton, S. Lori Brown, Robert N. Hoover. Annals of Epidemiology, May 2001;11(4):248-256.
For Q&A on the relationship of breast implants to breast cancer risk, visit http://www.cancer.gov/newscenter/siliconeqanda