Efficacy and side effects of dacarbazine in comparison with temozolomide in the treatment of malignant melanoma: a meta-analysis consisting of 1314 patients.

The widespread prevalence of melanoma, one of the most malignant forms of skin cancer, is increasing rapidly. Two chemotherapeutic regimens are commonly used for the palliative treatment of malignant melanoma: intravenous administration of single-agent dacarbazine or oral administration of temozolomide. The aim of this study was to compare the effectiveness and side effects of dacarbazine with those of temozolomide through a meta-analysis. A thorough literature bibliography search was conducted up to 2012 to gather and review all randomized clinical trials comparing the use of dacarbazine with that of temozolomide in the treatment of malignant melanoma. Three head-to-head randomized clinical trials comprising 1314 patients met the criteria and were included. Comparison of temozolomide with dacarbazine yielded a nonsignificant relative risk (RR) of 0.83 [95% confidence interval (CI) = 0.26-2.64, P = 0.76] for complete response, a nonsignificant RR of 1.05 (95% CI = 0.85-1.3, P = 0.65) for stable disease, and a nonsignificant RR of 2.64 (95% CI = 0.97-1.36, P = 0.11) for disease control rate. The RR for nonhematologic side effects and hematologic side effects, such as anemia, neutropenia, and thrombocytopenia, of temozolomide compared with dacarbazine in patients with malignant melanoma was nonsignificant in all cases, but the RR for lymphopenia of temozolomide compared with dacarbazine was 3.79 (95% CI = 1.38-10.39, P = 0.01), which was significant. Although it is easier to administer oral medication, according to the results, there is no significant difference in the efficacy and side effects of these two drugs. Owing to the higher cost of treatment with temozolomide and the increased prevalence of lymphopenia on using temozolomide, use of dacarbazine as the first choice treatment for malignant melanoma is suggested.