Late Extended Adjuvant Treatment With Letrozole Improves Outcome in Women With Early-Stage Breast Cancer Who Complete 5 Years of Tamoxifen

摘要: Purpose The National Cancer Institute of Canada Clinical Trials Group MA.17 trial examined the efficacy letrozole (LET) started within 3 months 5 years adjuvant tamoxifen in postmenopausal hormone receptor–positive early-stage breast cancer. When was unblinded, patients who received placebo (PLAC) were offered LET. Patients and Methods This cohort analysis describes outcomes women assigned PLAC at initial random assignment after unblinding. Efficacy chose LET (PLAC-LET group) compared with those did not (PLAC-PLAC by hazard ratios P values calculated from Cox models that adjusted for imbalances between groups. Toxicity analyses included only events occurred Results There 1,579 PLAC-LET group (median time tamoxifen, 2.8 years) 804 PLAC-PLAC group. younger; had a better performance status; more likely to have node-positiv...