Sequential Local Injection of Low-Dose Interferon-Beta for Maintenance Therapy in Stage II and III Melanoma: A Single-Institution Matched Case-Control Study
To determine the beneficial effect of maintenance therapy in stage II and III melanoma by sequential local injection of low-dose interferon-β. 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-β maintenance therapy consisting of subcutaneous injection of natural interferon-β at a dose of 3 × 10(6) IU/day for 10 consecutive days, and 25 patients underwent observation alone. Compared with all patients, overall survival and relapse-free survival were significantly worse in the observation group than in the interferon-β 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-β group was stratified by subgroup, there was a statistical difference only between dosage and duration (p = 0.027 and p < 0.001, respectively). This study demonstrates that maintenance therapy by interferon-β 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-β.