ASCO: Tamoxifen for 10 Years in Women with HR-Positive, Non-Metastatic Breast Cancer

The American Society of Clinical Oncology (ASCO) today issued an update to its clinical practice guideline on the use of adjuvant endocrine therapy for women with stages I-III hormone receptor positive breast cancer.

The update reflects new data on the duration of tamoxifen treatment from five studies reviewed since ASCO’s 2010 update to this guideline. In the two largest randomized studies that had the longest follow-up, women who took tamoxifen for 10 years had a breast cancer survival advantage, as well as lower risks of breast cancer recurrence and contralateral breast cancer, compared to those who took tamoxifen for five years.

“Tamoxifen taken for five years has been the standard adjuvant endocrine treatment for decades, but we now have evidence to recommend up to 10 years of tamoxifen for women with hormone receptor-positive breast cancer,” said Harold J. Burstein, MD, PhD, co-chair of ASCO’s Expert Panel that wrote the guideline update. “Postmenopausal women also have the option of taking an aromatase inhibitor as an alternative to tamoxifen or in sequence after tamoxifen. Aromatase inhibitors are not recommended for premenopausal women.”

Source: ASCO