January 2013 Ask the Expert: ATLAS Study on Tamoxifen

January 1, 2013

During the month of January, Living Beyond Breast Cancer expert Adam Brufsky, MD, PhD, answered your questions about ATLAS, a major new study that has shown that tamoxifeninfo-icon treatment for estrogen receptor-positiveinfo-icon breast cancer is even more beneficial when taken for 10 years instead of five. These questions were submitted during our January 9, 2013 webinar on News From the San Antonio Breast Cancer Symposium.

Question: Please describe the ATLAS trial: What was its goal, who was eligible to participate and what did it conclude?

Dr. Brufsky: The ATLAS trial randomized about 6,800 women who had been on tamoxifeninfo-icon for five years to either continue taking it for another five years or to stop. The goal was to see if another five years of tamoxifen treatment further reduced the risk of recurrenceinfo-icon in years five to 10 and beyond.

The trial concluded that women who take 10 years of tamoxifen had less risk of breast cancer recurrence than women who stop after year five. It is interesting that most of this risk reduction occurred in years 10 and beyond. 

Question: Do the results impact women of all ages the same? Are there special considerations for younger premenopausal women compared to postmenopausal women?

Dr. Brufsky: The results were good for both premenopausalinfo-icon women and postmenopausalinfo-icon women, although the postmenopausal women on 10 years of tamoxifeninfo-icon had a higher risk of endometrial (uterine) cancer in years five through 10. There also were only about 700-800 premenopausal women in the study.

Question: Women who take aromatase inhibitors are curious if the findings from the ATLAS trial can be applied to their length of hormonal therapy treatment. How do you counsel women who are taking an AI and reaching the five-year mark? What questions should women taking an AI be asking their doctors?

Dr. Brufsky: We have a current trial, NSABP B-42, which is trying to answer the question of five versus 10 years of AIs. This trial has not reported results yet. What I tend to do is offer two to five more years of an aromatase inhibitorinfo-icon to women at a higher risk of recurrenceinfo-icon (stageinfo-icon II and above). Women who continue therapyinfo-icon beyond five years may have a higher risk of osteoporosisinfo-icon and elevated cholesterol.

Question: Would you recommend 10 years of tamoxifen treatment for women now? Please explain.

Dr. Brufsky: I am now offering 10 years of tamoxifeninfo-icon to premenopausalinfo-icon women with breast cancer that is stages II and above. For postmenopausalinfo-icon women who happen to be on five years of tamoxifen, I change them to an aromatase inhibitorinfo-icon, which has no increased risk of uterine cancer, after they finish five years of tamoxifen treatment.