Question:

I was diagnosed with breast cancer 5 years ago and since then have taken Tamoxifen for 3 years and Arimidex for 2 years. Now what? My doctor is suggesting that I start taking Evista. I can`t find any information on suggested treatments for breast cancer after five years. Where might I look for information? Thank you.

Answer:

This is a question for which there is no clear answer, but here is what we do know: There are good trials showing the effectiveness of “switching” from tamoxifen to Arimidex using 2-3 years of each drug (the treatment you have completed). There is a large body of experience with a full 5 years of tamoxifen followed by five years of another aromatase inhibitor, letrozole. Raloxifene is a drug which can prevent new cancers in those at high risk, but I am not aware of any experience with the drug in cancer survivors to reduce late recurrences. Its primary use is to prevent and treat osteoporosis in postmenopausal women. As an aside, you did not state your age, but I assume you are postmenopausal, as aromatase inhibitors are only effective in such women. Also, this treatment has only been studied in invasive breast cancer.

For patients who switch from tamoxifen between two and three years, we do not know if any additional aromatase inhibitor is helpful. There is an ongoing national NSABP trial that may answer the question and perhaps the trial is open somewhere in your community. On the study, women are randomized to additional aromatase inhibitor (drugs such as Arimidex or letrozole) or placebo after completing a course of treatment like yours, because experts are studying what to do at completion of five years of combined tamoxifen/aromatase inhibitor treatment. If this study, called B-42, is available to you, I suggest you consider joining. You might go to the NSABP website and look at the contact list for the study for participating institutions in your area. Try this link: http://www.nsabp.pitt.edu/B42_Information.asp. Outside of a clinical trial, I usually balance the risks and side effects of continuing the aromatase inhibitor for a full 5 years against the risk of cancer recurrence. This becomes a discussion with the patient balancing these factors.

For more information:

Go to the Breast Cancer health topic.