CHEMOTHERAPY WITH MITOMYCIN-C AND VINBLASTINE IN PRETREATED METASTATIC BREAST-CANCER

Aims: In February 1986 we began a study to test the activity of mitomy cin C (12 mg/m2) plus vinblastine (6 mg/m2 on day 1 of a 28-day cycle (MV) as second or third-line chemotherapy for metastatic breast cancer patients. Methods: As of February 1988 the study was stopped after 26 patients had been enrolled. The median age of the patients was 54 yea rs (range 35-78); all patients were progressive from chemotherapy; 15 (57.7 %) patients were treated as second and 11 (42.3 %) as third line ; 19 (73.1 %) patients had received anthracyclines as first (13 patien ts) or second-line (6 patients) chemotherapy; 18 (69.2 %) patients had visceral involvement; 7 (26.9 %) had one metastatic site, 11 (42.3 %) two sites, 6 (23.1 %) three sites and 2 (7.7 %) four sites. Results: Overall, 86 cycles were administered, with a median number of 3 cycles per patient. Toxicity was mild; hematologic side effects required dis continuation of treatment in 3 cases. Vomiting occurred in 3 (11.5 %) patients, nausea in 5 (19.2 %). Moderate neurologic toxicity was recor ded in 6 (23 %) patients. No complete and 3 partial responses were obs erved. The objective response rate was 11.5 % (exact 95 % confidence i nterval, 2.4-30.1). Responses occurred independently of disease-free i nterval, dominant metastatic site, response to previous chemotherapy, previous anthracycline and line of treatment; all responses were recor ded in patients under 50 years of age. Kaplan-Meier estimated median t ime to progression and overall survival were 13 and 40 weeks, respecti vely. Conclusion: The MV regimen was well tolerated but showed little activity in pretreated metastatic breast cancer.