HealthDay News — Older breast cancer survivors taking letrozole for more than the recommended five years may not live longer; however, other benefits may result, so the decision to extend use is one best made on a case-by-case basis, according to findings presented at the annual San Antonio Breast Cancer Symposium, held from December 6 to 10 in Texas.
Researchers tracked outcomes for 3,923 postmenopausal women with early-stage hormone receptor-positive breast cancer. The women took either letrozole or a placebo for an average of about two years after an initial five years of aromatase inhibitor therapy.
The researchers found that women who took letrozole for those extra two years did not experience statistically significant higher rates of disease-free survival or overall survival than those in the placebo group. However, women who extended their use of letrozole showed a 29% reduction in breast cancer recurrence, and a 28% reduction in tumors arising at locations outside the breast.
Women who took letrozole for the additional years also experienced a “small increase in the risk of arterial thrombotic events after 2.5 years,” Terry Mamounas, MD, MPH, medical director of the Comprehensive Breast Program at the University of Florida Health Cancer Center in Orlando, said in a news release from the American Association for Cancer Research. This slight uptick in cardiovascular risk means that older women considering extra time on the drug “will require careful assessment of potential risks and benefits,” he added.
The study was funded in part by Novartis, the manufacturer of letrozole.