Key clinical point: Breast cancer recurrence rates are similar with anastrozole and tamoxifen in postmenopausal women with hormone receptor–positive ductal carcinoma in situ, results of the IBIS-II DCIS study suggest.

Major finding: At a median follow-up of 11.6 years, the rate of breast cancer recurrence was 9.7% with tamoxifen and 8.5% with anastrozole (hazard ratio, 0.89; P = .401).

Study details: A phase 3 trial of 2,980 postmenopausal women with hormone receptor–positive ductal carcinoma in situ who were randomized to 5 years of anastrozole or tamoxifen.

Disclosures: The trial was funded by Cancer Research UK, the National Health and Medical Research Council Australia, Breast Cancer Research Foundation, AstraZeneca, and Sanofi Aventis. Two investigators disclosed relationships with AstraZeneca, and one disclosed a relationship with Cancer Research UK.