Sequential local injection of low-dose interferon-beta for maintenance therapy in stage II and III melanoma: a single-institution matched case-control study.

ABSTRACT

OBJECTIVE: To determine the beneficial effect of maintenance therapy in stage II and III melanoma by sequential local injection of low-dose interferon-ß. METHODS: We reviewed 46 patients with stage II and III primary melanoma at our institution from 2004 through 2009. Twenty-one patients were treated with interferon-ß maintenance therapy consisting of subcutaneous injection of natural interferon-ß at a dose of 3 × 10(6) IU/day for 10 consecutive days, and 25 patients underwent observation alone. RESULTS: Compared with all patients, overall survival and relapse-free survival were significantly worse in the observation group than in the interferon-ß group (p = 0.024 and 0.029, respectively). In stage II, a significant difference in overall survival, but not in relapse-free survival, was seen between the two groups (p = 0.041). When the interferon-ß group was stratified by subgroup, there was a statistical difference only between dosage and duration (p = 0.027 and p < 0.001, respectively). CONCLUSIONS: This study demonstrates that maintenance therapy by interferon-ß is beneficial in the outcome of the disease without substantial toxic effects, especially in patients with stage II melanoma. Extension of the duration of treatment beyond 2 years could further improve the therapeutic efficacy of interferon-ß.