Delayed adjuvant tamoxifen: Ten-year results of a collaborative randomized controlled trial in early breast cancer (TAM-02 trial)

Aim:Immediate adjuvant tamoxifen reduces disease recurrence andimproves survival in patients with early breast cancer. However, is it toolate to administer tamoxifen to patients who have already undergone treatment,but were unable to benefit from this adjuvant therapy? The French NationalCancer Centers (FNCLCC) have investigated the efficacy of delayed tamoxifenadministration in a randomized controlled trial.Patients and methods:From September 1986 to October 1989, womenwith primary breast cancer, who had undergone surgery, radiotherapy, and/orreceived adjuvant chemotherapy but not hormone therapy more than two yearsearlier, were randomized to receive either 30 mg/day tamoxifen or notreatment. The 10-year disease-free and overall survival rates of the twogroups of patients and of various subgroups were determined according to theKaplan–Meyer method and compared by the log-rank test.Results:This intention-to-treat analysis comprised 250 women inthe tamoxifen group and 244 in the control group. Patient characteristics(age, T stage, number of positive nodes, receptor status, and interval sincetumor treatment) were comparable in both groups. Delayed adjuvant tamoxifensignificantly improved overall survival only in node-positive patients and inpatients with estrogen receptor-positive (ER+) or progesteronereceptor-positive (PR+) tumors. Disease-free survival, however, wassignificantly improved in the global population and in several patientsubgroups (node-positive, ER+, PR+). Patients in whom the interval betweenprimary treatment and delayed adjuvant tamoxifen was greater than five yearsalso had significantly improved disease-free survival.Conclusions:Overall and disease-free survival results indicatethat delayed adjuvant tamoxifen administration (30 mg/day) is justified inwomen with early breast cancer, even if this treatment is initiated two ormore years after primary treatment.