Efficacy of isolated limb perfusion (ILP) in patients with Merkel cell carcinoma (MCC): A multicenter experience

BACKGROUND: Merkel cell carcinoma (MCC) is a rare and potentially aggressive neuroendocrine tumor of the skin, with a propensity for locoregional metastases. In two expert referral centers, isolated limb perfusion (ILP) is used to obtain locoregional control in selected locoregionally advanced MCC patients. This study describes our experience.METHOD: Patients who underwent ILP for MCC were analyzed. ILP was performed with melphalan and tumor necrosis factor (TNF) combination therapy. Depending on the institution, either a normothermic or a hyperthermic temperature regimen was used. Baseline characteristics, toxicity data, locoregional progression-free survival (LPFS) and overall survival (OS) were assessed.RESULTS: Four males and 6 females with a median age of 78 years (IQR 61-84 years) were included. Four patients underwent ILP for upper extremity disease and 6 for lower extremity disease. All patients received combination therapy with Melphalan and TNF, one patient with the addition of interferon-gamma. No signs of systemic toxicity were present post-ILP. Severe locoregional toxicity (compartment syndrome) occurred in 1 patient and 1 elderly patient with extensive atherosclerosis had to undergo transfemoral amputation due to critical ischemia. Eight patients could be included for response evaluation. The overall response rate (ORR) was 87.5% with a complete response (CR) rate of 62.5%. Two long-term responses of 53 months and 71 months were observed. Median LPFS was 5 months and median OS was 54 months.CONCLUSION: ILP shows a high CR rate that can be durable. Therefore, ILP should be considered an effective treatment modality for locally advanced MCC.