Recent results of a trial revealed that oncologists can now offer post-menopausal women with ductal carcinoma in situ (DCIS) anastrozole and tamoxifen to prevent recurrence of breast cancer.

Results from two randomized trials showed that selection of any of the drug can be a good choice for the majority of patients, said researchers. The conclusions were given after studying results of placebo-controlled trials that involved around 4,200 patients.

The IBIS-II DCIS trial, conducted in Europe, Australia, and New Zealand, and the NRG/Oncology/NSABP B-35 trial showed that anastrozole and tamoxifen are comparably effective for preventing recurrence of both DCIS and invasive breast cancers in postmenopausal women.

Although the drugs can prevent recurrence of breast cancer, they have distinct adverse event profile, which may drive drug choice in individual patients.

Jack Cuzick, PhD, director of the Wolfson Institute of Preventive Medicine, said, “Overall, there's no clear differences in efficacy of a slight favor, I think, in terms of anastrozole when you look at all of the data”.

Dr Cuzic is also the lead author of the report on the IBIS-II DCIS trial, results of which were presented at San Antonio Breast Cancer Symposium (SABCS) 2015 and were published simultaneously in the Lancet.

Previously conducted studies have shown that anastrozole and other third-generation aromatase inhibitors (AIs) are more effective than tamoxifen in preventing recurrence of invasive, hormone receptor– positive breast cancer in postmenopausal women.