Extending Hormonal Drugs Therapy for Breast Cancer Might Decrease Risk of Recurrence, New Study Shows

A new study reveals that older women with breast cancer who have an extended anti-estrogen therapy up to 10 years have lower risk of recurrence and lesser chance of contralateral breast cancer, compared to those who only took the hormonal drugs for five years.

At present, health care providers have been prescribing aromatase inhibitor, such as letrozole, as a 5-year up-front monotherapy for hormone-receptor-positive early breast cancer in postmenopausal women. On the other hand, tamoxifen is the preferred treatment for women who have not yet in the menopausal stage.

Previous study has proved the efficacy of extending the tamoxifen treatment for 10 years. However, it is not clear whether extended intake of letrozole, up to ten years, will yield similar results.

For the study, researchers enrolled 1,918 postmenopausal women. All the women have been taking letrozole for about five years, while some were also previously treated with tamoxifen. The researchers divided the participants into two groups. The first group was given daily pill of letrozole for an additional of five years, while the other group was given placebo.

After a median follow-up of 6.3 years, researchers noted a total of 165 recurrences or occurrence of cancer on the other breast. 67 of those belong to the extended letrozole group, while the remaining 98 were in the placebo group.

This suggests a 34 percent reduction in recurrence for those who take letrozole for five more years.

However, researchers did not find any significant difference in the overall survival between the letrozole and the placebo group. They noted that when the breast cancer recurs it was usually at stage four and is lethal for both groups.

Researchers believe that their findings will help future treatments for breast cancer, but they still remain reluctant in suggesting a five year extension of letrozole to all postmenopausal cancer patients due to the possible side effects of the hormonal drugs. Letrozole is known to cause joint pain and brittle bones, leading to fractures and early on-set of osteoporosis.

"This gives us data to take back to the clinic to talk to our patients about," said Claudine Isaacs, a medical oncologist at Georgetown University's Lombardi Comprehensive Cancer Center, in a report from Washington Post.

"If I had a patient who doesn't have side effects from this therapy and has a higher risk of recurrence, I'd consider extending it - or at least having an informed discussion with her."