Tamoxifen

Many of you may have seen the article in the New York Times and other news media outlets relative to the breast cancer drug tamoxifen. As many of you know, I was involved in the STAR trial which compared tamoxifen and raloxifene for breast cancer prevention. Much of my academic work has been involved in the ultrasound appearance of the uterus in patients receiving tamoxifen therapy. I’ve had a long standing interest in the treatment of estrogen receptor positive breast cancers and selective estrogen receptor modulators (SERMs) like tamoxifen and raloxifene.

The point of this article was to report on a rather large trial known as ATLAS that involved almost 7,000 women with estrogen receptor positive breast cancer. The women came from over 30 countries. They were randomized to tamoxifen for 10 years versus those who stopped after the traditional 5 year time period. The group who took tamoxifen for 10 years had less recurrence of their breast cancer even after they stopped tamoxifen at the 10 year time frame. In addition, there were fewer women who died in the group that took tamoxifen for 10 years versus those who took it for 5 years. There were slightly more cases of uterine cancer in the women who took tamoxifen for the extra 5 years. However, the number of deaths from this was much smaller than the incremental number of deaths from breast cancer.

Thus, it appears that taking tamoxifen for 10 years versus taking it for 5 years offers a significant advantage to those women with estrogen receptive positive breast cancers. If you or someone you know has been on tamoxifen and stopped after 5 years, there is no cause for alarm. The possibility exists, however, that perhaps resuming tamoxifen therapy for some women in this situation might be of some additional value. I suggest that you discuss this with either your breast oncologist or feel free to schedule a visit for further consultation.