Complete remissions in metastatic breast cancer treated with combination drug therapy.

One hundred sixteen patients with metastatic breast cancer who achieved complete remission with combination chemotherapy were analyzed to ascertain the factors that affect the duration of complete remission and the patterns of relapse. The median duration of complete remission was 17 months. Disease recurred in 81 patients (70%) at periods ranging from 3 to 44 months after achievement of complete remission. The duration of complete remission was inversely related to the bulk of metastatic tumor. Twenty-three patients treated with combined oophorectomy and chemotherapy experienced the longest remissions (median duration of 33 months); only eight (35%) of them have relapsed. Seventy-six percent of the relapses occurred in previously known sites of tumor involvement; most of the remainder involved the brain. The short duration of complete remissions and tendency to relapse in sites of initial involvement suggest that patients with metastatic breast cancer who achieved complete remission with combination chemotherapy still had substantial residual tumor. Consolidation treatments, using hormonal therapy and non-cross-resistant chemotherapy along with irradiation to initial sites of metastases, whould be investigated to ascertain their usefulness in prolonging the remissions.