NCCN Guidelines Version 2.2025 for Merkel Cell Carcinoma
July 1, 2025
The National Comprehensive Cancer Network (NCCN) is a group of top cancer centers in the U.S. that publishes yearly treatment guidelines for different cancers. These guidelines help doctors understand how to best treat their patients. The 2025 NCCN guidelines for Merkel cell carcinoma (MCC) include important changes from the 2024 guidelines based on the latest research. Key changes that are relevant to most patients include:
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Recommending that patients are monitored with a blood test called ctDNA (circulating tumor DNA), which can be used to check if MCC is coming back.
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If radiation therapy is recommended after surgery (called adjuvant radiation), it should ideally begin as soon as the surgical wound has healed—preferably within 8 weeks—to help reduce the risk of Merkel cell carcinoma coming back. That said, treatment plans for MCC can vary, and both the need for radiation and the best time to start it may differ depending on each person’s situation.
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For patients who are unable to undergo standard radiation schedules with many sessions
(e.g. 25 treatments of 2 Gray (unit of energy) over 5 weeks for a total of 50 Gray), the new guidelines support an alternative called hypo-fractionated radiation therapy. This approach delivers higher doses of radiation in fewer sessions (e.g. 8Gy in one session, total 8Gy), resulting in a lower total dose overall and a shorter treatment course. -
After the initial diagnosis of Merkel cell carcinoma, a referral to a specialized cancer center is recommended. These centers offer multidisciplinary care, where experts in skin cancer, surgery, radiation, and medical oncology work together to create the most effective treatment plan for each patient.
These updates give doctors more tools to treat MCC effectively and help patients get better, up-to-date care. To see the full NCCN 2025 Guidelines for MCC, click here: