In this issue of JAMA Oncology, Friedl and colleagues1 report results of the SUCCESS-A trial in which 2987 women were randomized to receive zoledronate either for 5 years (4 mg intravenously every 3 months for 2 years, then every 6 months for 3 years) or for 2 years (4 mg intravenously every 3 months). Eligible women had invasive breast cancer at high risk of recurrence: either node-positive or node-negative with a tumor size greater than 2 cm, histological grade 3, negative hormone-receptor status, or in women 35 years or younger. Both premenopausal and postmenopausal women participated; they received adjuvant chemotherapy, and zoledronate treatment was started after its completion. Women with hormone receptor–positive cancer received endocrine treatment for 5 years. Analysis of SUCCESS-A at a median of 5 years after initiation of zoledronate showed no significant difference in its primary end point of disease-free survival (DFS) for women receiving 5-year or 2-year adjuvant zoledronate (hazard ratio [HR], 0.97; 95% CI, 0.76-1.25; P = .83). There was also no statistically significant difference in overall survival (OS), distant disease-free survival, and bone recurrence–free survival. There were no discernable trends for subgroups defined by menopausal or hormone-receptor status.