Background: Advanced melanomas (non-resectable Stage-III/IV) are fatal, with few effective treatments. It remains unclear if other drugs offer improvements over the standard, dacarbazine.
Purpose: We quantified objective response rates (Complete+Partial response) of dacarbazine versus comparators for advanced cutaneous melanoma.
Methods: We retrieved all head-to-head randomized controlled trials involving dacarbazine and other drugs/combinations. Two reviewers searched MEDLINE (1966-Jan 2006), EMBASE (1980-2006), CINAHL (1982-2006) and Cochrane library, then compared results. Differences were resolved through consensus. Rates were combined using random effects meta-analysis. chi2 tested heterogeneity; points from Jadad's method were assessed to examine study quality.
Results: We found 48 studies having 111 active treatment arms [24 with dacarbazine monotherapy (n=1390), 75 with dacarbazine combinations (n=4962), and 12 with non-dacarbazine treatments (n=783)] treating 7135 patients. Overall, study quality was poor. Response to dacarbazine monotherapy ranged between 5.3% and 28.0% (average 15.3%), OR=1.31, CI(95%): 1.06-1.61; N=3356. Partial responses comprised 73% of successes. Only adding interferons improved response rates (OR=1.69, CI(95%): 1.07-2.68, N=778) but survival duration was not significantly longer (P=0.32), and trials with larger sample sizes found lower success rates. All other treatments alone or in combination were ineffective P>0.05.
Conclusions: Dacarbazine generally produces poor outcomes. Adding other therapies offers minimal clinical advantages (possibly with interferons). In general, study quality was poor and sample sizes were small. This meta-analysis highlights the unmet need for effective treatment options for advanced melanoma.