Breast implants not associated with an increased risk of cancer

Having breast implants is not associated with an increased risk of cancer overall, a new study reports in the April 19 issue of the Journal of the National Cancer Institute.

Implants were associated with a decrease in breast cancer risk and an increased lung cancer risk, but these results likely reflect the lifestyles and smoking habits of the women in the study rather than an effect of the implants themselves, the authors conclude.

Past reports have examined the association between cosmetic breast implants and cancer risk, particularly breast cancer risk, but no consistent associations have been found. However, few studies have examined this association after more than 15 years.

Joseph K. McLaughlin, Ph.D., of the International Epidemiology Institute in Rockville, Md., and Vanderbilt-Ingram Cancer Center in Nashville, and colleagues examined the incidence of cancer in a nationwide cohort of 3486 Swedish women who underwent cosmetic surgery for breast implants between 1965 and 1993 and were followed until the end of 2002. Data was obtained from the Swedish Cancer Registry, which reports on cancer occurrence for the entire country. The average follow-up time was 18.4 years. The study is the longest follow-up study on cosmetic breast implants and risk of cancer incidence to date.

The authors identified 180 cancers in women with breast implants, fewer than the 193.1 predicted to occur in this population. Cosmetic implants were not associated with an increased risk of cancer overall. Women with implants had an increased incidence of lung cancer (20 cases observed, 9.1 cases expected) and a decreased incidence of breast cancer (53 cases observed, 71.9 cases expected) compared with the general population.

The authors suggest the higher incidence of lung cancer may be due to the high rates of smoking in Swedish women with cosmetic breast implants. Lower breast cancer incidence could be explained by the lower body mass index, higher number of births, and younger age at first childbirth observed in the group of women who had undergone breast implantation.

The authors write, "After an average follow-up of 18 years, and a maximum follow-up of 37 years, we found that women who have undergone breast implantation have a reduced risk for breast cancer, most likely due to differences in lifestyle or reproductive characteristics. We also found no increased risk for brain cancer or for lymphoma, sarcoma, or multiple myeloma," cancers of concern because of earlier suggestive observations.

http://jncicancerspectrum.oxfordjournals.org