In two newly published reports by the National Cancer Institute (NCI), researchers found that silicone-gel filled breast implants do not Silicone Breast Implants Do Not Increase Risk of Most Cancers (dateline May 1, 2001) | Breast Health News | Imaginis - The Women's Health & Wellness Resource Network

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Silicone Breast Implants Do Not Increase Risk of Most Cancers (dateline May 1, 2001)

In two newly published reports by the National Cancer Institute (NCI), researchers found that silicone-gel filled breast implants do not put women at higher-than-average risk for most cancers. In fact, previous findings have shown that women who get breast implants for cosmetic reasons tend to be in better health than the general population. However, the NCI researchers did find that deaths from suicide, brain cancer, and respiratory cancers are higher among women with silicone breast implants when compared to women who have other types of plastic surgery. The reasons for the increased risk in these types of conditions is unknown.

According to lead researcher Dr. Louise Brinton, despite the negative findings about brain and respiratory cancers, the findings are generally reassuring and should help lay to rest much of the concern surrounding silicone breast implants. The study is one of the largest ever conducted on the long-term health effects of silicone breast implants. The U.S. Food and Drug Administration (FDA) imposed a ban on the general use of silicone breast implants in 1992 after questions arose concerning their safety.

The two reports of the latest NCI study were published in the May issues of Epidemiology and Annals of Epidemiology. The study followed 13,500 women from 18 plastic surgery practices who had implant surgery for cosmetic reasons (none of the women in the study got implants after having breast cancer). These women were compared to a control group of 4,000 women who had other types of plastic surgery, such as liposuction (removal of fat) of the stomach or thighs or the removal of facial wrinkles. Researchers previously determined that other plastic surgery patients are usually more appropriate to compare with implant patients than the general population because women in these groups share certain similarities. The women were followed for an average of 13 years.

When compared to the general population, the researchers found all cancers, circulatory and digestive system diseases, endocrine, nutritional, metabolic and immune diseases, and cirrhosis of the liver occurred less often in women who had implant surgery. In addition, when the women with breast implants were compared to women who had other cosmetic surgeries, the researchers found that the rates for several other cancers (including mouth, stomach, large intestine, breast, cervix, uterus, ovary, bladder, thyroid, connective tissue, and immune system cancers) were also lower among the women with implants.

However, the researchers did find an increased risk for suicides, brain cancer, respiratory cancers, pneumonia, and emphysema among the women who had silicone breast implants. According to the NCI, the higher suicide rates of the implant patients correlate with characteristics described among implant patients in previous reports, including marital difficulties, depression, emotional disorders, and low self-esteem.

The reasons for the increased risk of respiratory cancers remains unclear. In a news release, the NCI said there is not enough information to evaluate whether the increase in respiratory cancers is related to silicone exposure or to higher smoking rates among implant patients. Since the majority of the implant patients in the study who developed respiratory cancers had died and obviously could not fill out the researchers’ questionnaires about lifestyle, the researchers were unable to determine whether there were other factors that could explain why these women had a higher incidence of respiratory cancers when compared with women who underwent other types of plastic surgeries.

Similarly, the researchers do not know why there was a higher incidence of brain cancer among implant patients in the study. Data on how silicone breast implants affect neurological pathways remains inconsistent. The researchers suggest that the findings may have occurred by chance or may be related to other factors that the implant patients had in common.

The American Society of Plastic Surgeons (ASPS) recently released a statement regarding breast implants: "Women with breast implants should be reassured by the consistency of scientific studies that have uniformly found they are not at increased risk for cancer." In an ASPS news release, NCI panel member and ASPS member Thomas Mustoe, MD, professor in chief at Northwestern University, said, "The excess of cancers found in the Epidemiology study are more likely due to chance than a true association with implants."

Last October, the NCI reported that silicone breast implants were not linked to a higher-than-average risk of breast cancer. Also, a recent study conducted by researchers from Harvard Medical School found no association between breast implants (silicone or saline-filled) and an immune-related disorder. In 1999, a 13-member panel of national scientific experts also found that breast implants do not cause cancer or other autoimmune disorders. The report, which was published in the Journal of the National Cancer Institute, involved an analysis of over 3,000 publications and personal testimonies from more than 60 women.

The National Cancer Institute estimates that approximately 1.5 million to 2 million American women have undergone implant surgery since 1962, when implants were first introduced on the market. Approximately 80% of women get implants for cosmetic reasons while 20% get implants to reconstruct their breasts after breast cancer surgery (mastectomy).

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