Chemo, tamoxifen cut risk of second breast cancer

Both tamoxifen and chemotherapy reduce the long-term risk of developing a second cancer in the unaffected breast, according to a report published in the January 2, 2008 issue of the Journal of the National Cancer Institute. The risk reduction lasts for at least 10 years with chemotherapy and 5 years with tamoxifen. The study analyzed 1,158 women who had cancer in one breast and an additional 634 who initially had cancer in one breast followed by development of cancer in the second breast. All subjects were diagnosed with breast cancer before age 55. Results showed that chemotherapy was connected with a 43% reduced risk of developing cancer in the second breast compared to no chemotherapy, a reduction that persisted for 10 years after diagnosis. Tamoxifen use was associated with a 34% reduced risk compared with no tamoxifen use, a reduction that continued for 5 years after diagnosis.