January 2013 Ask the Expert: ATLAS Study on Tamoxifen
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 tamoxifen treatment for estrogen receptor-positive 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.
Can the findings from the ATLAS trial be applied to the length of hormonal therapy treatment for women on aromatase inhibitors? 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: The ATLAS trial randomized about 6,800 women who had been on tamoxifen 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 recurrence 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.
Dr. Brufsky: The results were good for both premenopausal women and postmenopausal women, although the postmenopausal women on 10 years of tamoxifen 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 inhibitor to women at a higher risk of recurrence (stage II and above). Women who continue therapy beyond five years may have a higher risk of osteoporosis and elevated cholesterol.
Dr. Brufsky: I am now offering 10 years of tamoxifen to premenopausal women with breast cancer that is stages II and above. For postmenopausal women who happen to be on five years of tamoxifen, I change them to an aromatase inhibitor, which has no increased risk of uterine cancer, after they finish five years of tamoxifen treatment.