Correlates of outcome in patients with metastatic melanoma treated with dacarbazine

Purpose: To identify correlates of overall and progression-free survival in patients with metastatic melanoma treated with dacarbazine chemotherapy.Patients and methods: A retrospective single institution analysis was performed on a cohort of 109 patients with stage IV melanoma, who received chemotherapy with dacarbazine 750 to 1000mg/m2 every three weeks [median 3 cycles (range 1 – 17)]. Multivariate proportional hazard models were used to examine the effects of key clinical indicators (age, gender, performance status (PS), primary site and stage, local/regional recurrence status, metastasis-free survival, sites of metastases, LDH, neutrophil levels and prior chemotherapy or immunotherapy).Results: Median overall survival from the 1st metastasis was 12 months (95% C.I., 9.9 to 15.3 months); median progression-free survival was 2.3 months (95% C.I., 2.0 to 3.0 months). Median time to first metastasis was 32 months (95% C.I., 22 to 38 months). 57% of patients were still alive 6 months after starting dacarbazine chemotherapy. CR was observed in 7 (6.0%) patients and PR in 16 (15%). Of these 23 responders, the average duration of response was 13.4 months (95% C.I. 6 to 21 months). Presence of bone metastases (HR: 2.72), liver metastases (HR: 2.40), primary site in a non chronic sun-exposed area (HR: 2.5), and ECOG PS > 1 (HR: 1.5) were significant negative correlates of overall survival. Similar results were obtained for progression-free survival. ECOG > 1 (OR = 2.8) was the only correlate of non-response to dacarbazine.Conclusion: The presence of bone metastases, liver metastases, poor performance status and primary melanoma from non sun-exposed areas are independent negative correlates of overall survival and progression-free survival in patients with etastatic melanoma treated with dacarbazine. Performance status is the only clinical correlate with response.