Purpose: To determine the long-term clinical course of patients with metastatic breast cancer (MBC) who achieved a complete remission with doxorubicin-alkylating agent-containing combination chemotherapy programs.
Patients and methods: To assess the long-term prognosis of MBC, we reviewed our experience with 1,581 patients treated on consecutive doxorubicin and alkylating agent-containing front-line treatment protocols between 1973 and 1982. Treatment was administered for a maximum duration of 2 years. Characteristics of long-term survivors were evaluated, and hazard rates for progression were calculated.
Results: From this group, 263 (16.6%) achieved complete responses (CR) and 49 (3.1%) remained in CR for more than 5 years. After a median duration of 191 months, 26 patients remain in first CR, four patients died in CR at times ranging from 118 to 234 months, 18 patients died of breast cancer, and one is alive with metastatic disease. Compared with the overall CR and total patient populations, the long-term CR group had more premenopausal patients, a younger median age, a lower tumor burden, and better performance status. The hazard function shows a substantial drop in risk of progression after approximately 3 years from initiation of therapy. Ten long-term CR patients developed second primary cancers: breast (3), ovary (2), pancreas (1), endometrium (1), colon (1), head and neck (1), and lung (1).
Conclusion: Most patients with MBC treated with systemic therapies have only temporary responses to treatment, but some patients continue in CR following initial treatment. These data show that a small percentage of patients achieve long-term remissions with standard chemotherapy regimens. Remission consolidation strategies are needed.