Advanced Merkel cell carcinoma-A focus on medical drug therapy.

Merkel cell carcinoma (MCC) is a rare but aggressive non-melanoma skin cancer with significant morbidity and mortality. Treatment of choice for primary and locoregional MCC is complete surgical removal with sentinel lymphonodectomy and postsurgical radiotherapy of tumor basin and locoregional lymph nodes. In nonresectable and advanced tumors, drug therapy is indicated. While cytotoxic chemotherapy has resulted in higher response rates, overall survival remained nearly unaffected. With a better insight into tumor development and biology, new treatment s became available. Immune checkpoint inhibitors result in durable responses with a better safety profile that classical combined chemotherapy. Combinations of immune checkpoint inhibitors with and without radiotherapy help to overcome acquired drug-resistance. New compounds for vaccination and oral use are on the horizon. Despite all progress, treatment of MCC remains a challenge that needs close interdisciplinary teamwork.