Long-term response of isolated limb perfusion with hyperthermia and chemotherapy for Merkel cell carcinoma

Introduction: Merkel cell carcinoma (MCC) is a very rare and aggressive neoplasm. Due to its rarity, therapeutic guidelines are not well established, especially for regionally advanced disease. Hyperthermic isolated limb perfusion (HILP) with Melphalan and either with or without tumor necrosis factor-alpha (TNF-α) is becoming more common in clinical practice, yet the long-term response is not clear. Previous reports have established indications for treatment of unresectable MCC as well as the outcome of MCC patients receiving perfusion treatment in combination with other therapies (e.g., radiation). Method: A review was performed of the most important articles in MEDLINE from the last 20 years related to HILP and MCC. It was possible to collect all cases of HILP from the literature. Details of one case of MCC where HILP was administered was included in the literature review. Results: A total of nine cases of MCC receiving ILP were identified in the literature; of these, seven achieved a complete response, one a partial response and one no response. All five patients treated without TNF-α had a complete response. Of the four patients treated with TNF-α, two had complete, one partial and one no response. Conclusion: Based on the cases described, isolated limb perfusion is an acceptable option to treat regional advanced cases of MCC, and the use of TNF-α does not impact the overall response.