Long–Term Oncologic Outcomes After Isolated Limb Infusion for Locoregionally Metastatic Melanoma: An International Multicenter Analysis

Background: Isolated limb infusion (ILI) is a minimally invasive procedure for delivering high-dose regional chemotherapy to patients with locally advanced or in-transit melanoma located on a limb. The current international multicenter study evaluated the perioperative and long-term oncologic outcomes for patients who underwent ILI for stage 3B or 3C melanoma. Methods: Patients undergoing a first-time ILI for stage 3B or 3C melanoma (American Joint Committee on Cancer [AJCC] 7th ed) between 1992 and 2018 at five Australian and four United States of America (USA) tertiary referral centers were identified. The primary outcome measures included treatment response, in-field (IPFS) and distant progression-free survival (DPFS), and overall survival (OS). Results: A total of 687 first-time ILIs were performed (stage 3B: n = 383, 56%; stage 3C; n = 304, 44%). Significant limb toxicity (Wieberdink grade 4) developed in 27 patients (3.9%). No amputations (grade 5) were performed. The overall response rate was 64.1% (complete response [CR], 28.9%; partial response [PR], 35.2%). Stable disease (SD) occurred in 14.5% and progressive disease (PD) in 19.8% of the patients. The median follow-up period was 47 months, with a median OS of 38.2 months. When stratified by response, the patients with a CR or PR had a significantly longer median IPFS (21.9 vs 3.0 months; p < 0.0001), DPFS (53.6 vs 12.7 months; p < 0.0001), and OS (46.5 vs 24.4 months; p < 0.0001) than the nonresponders (SD + PD). Conclusion: This study is the largest to date reporting long-term outcomes of ILI for locoregionally metastatic melanoma. The findings demonstrate that ILI is effective and safe for patients with stage 3B or 3C melanoma confined to a limb. A favorable response to ILI is associated with significantly longer IFPS, DPFS, and OS.