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.