Effect of prior chemotherapy regimens on the efficacy of endocrine therapy within a German cohort of the TEAM trial.

Purpose: Prior chemotherapy may affect the efficacy of endocrine therapy.
Methods: The tamoxifen exemestane adjuvant multinational (TEAM) trial compared 5 years of adjuvant exemestane with the sequence of tamoxifen followed by exemestane in postmenopausal women with hormone-receptor-positive breast cancer. A total of 1,502 patients were enrolled in Germany (739 received tamoxifen followed by exemestan and 610 exemestan alone). A retrospective analysis of the German cohort of TEAM was conducted to determine whether prior chemotherapy affected clinical outcome of endocrine therapy.
Results: Overall survival, disease-free survival and distant recurrence were similar between patients who received sequential therapy and those who received exemestane monotherapy, irrespective of prior chemotherapy. Overall survival was not significantly different between patients who had received prior chemotherapy and those who had not (P = 0.2836). Disease-free survival and distant recurrence were significantly better in patients who had not received prior chemotherapy versus those who had (P = 0.0308 and P = 0.0001). In patients receiving sequential therapy, there were no significant differences in overall survival according to prior chemotherapy use (P = 0.1812). However, disease-free survival and distant recurrence were significantly different dependent on prior chemotherapy (P = 0.0143 and P = 0.0053).
Conclusion: In conclusion, there was no difference in overall survival between breast cancer patients who did receive prior chemotherapy before endocrine therapy and those who had not. Patients who had not received prior chemotherapy had significantly improved disease-free survival and less distant recurrence versus those who had received chemotherapy.