Based on previous meta-analyses of randomized controlled trials (RCTs), the use of interferon alpha (IFN-α) in the adjuvant setting improves disease-free survival (DFS) in patients with high-risk cutaneous melanoma. However, RCTs have yielded conflicting data on the effect of IFN-α on overall survival (OS).

We conducted a systematic review and meta-analysis to examine the effect of IFN-α on DFS and OS in patients with high-risk cutaneous melanoma. The systematic review was performed by searching MEDLINE, EMBASE, Cancerlit, Cochrane, ISI Web of Science, and ASCO databases. The meta-analysis was performed using time-to-event data from which hazard ratios (HRs) and 95% confidence intervals (CIs) of DFS and OS were estimated. Subgroup and meta-regression analyses to investigate the effect of dose and treatment duration were also performed. Statistical tests were two-sided.

The meta-analysis included 14 RCTs, published between 1990 and 2008, and involved 8122 patients, of which 4362 patients were allocated to the IFN-α arm. IFN-α alone was compared with observation in 12 of the 14 trials, and 17 comparisons (IFN-α vs comparator) were generated in total. IFN-α treatment was associated with a statistically significant improvement in DFS in 10 of the 17 comparisons (HR for disease recurrence = 0.82, 95% CI = 0.77 to 0.87; P < .001) and improved OS in four of the 14 comparisons (HR for death = 0.89, 95% CI = 0.83 to 0.96; P = .002). No between-study heterogeneity in either DFS or OS was observed. No optimal IFN-α dose and/or treatment duration or a subset of patients more responsive to adjuvant therapy was identified using subgroup analysis and meta-regression.

In patients with high-risk cutaneous melanoma, IFN-α adjuvant treatment showed statistically significant improvement in both DFS and OS.