Scottish Consensus Clinical Management Guidelines for Merkel cell cancer

Abstract

Merkel cell carcinoma (MCC) is a rare but highly aggressive neuroendocrine skin cancer with the highest mortality rate among skin cancers. Approximately 40 new cases are reported annually in Scotland, with a rising incidence. A significant proportion of these cases result in loco-regional recurrence and patient mortality. Historically, few phase 3 randomised controlled trials have been conducted for MCC, and the existing international guidelines are outdated and lack information on the recent advancements in immunotherapy, surgical margins, sentinel lymph node biopsy and post-operative radiotherapy. The 2024 joint guidelines by ESMO-EURA provide comprehensive best practice recommendations; however, there is no UK-specific guideline for the National Health Service (NHS). To address this gap, the Scottish Consensus Clinical Management Guidelines were developed by a multidisciplinary team of experts, including oncologists, surgeons, radiologists, nurse specialists, pathologists, dermatologists and Mohs surgeons from various NHS Scotland health boards. Initial meetings were held in December 2023, followed by further discussions in 2024, including the Scottish Clinical Imaging Network to ratify the use of PET-CT scans for initial imaging. The final draft of the guidelines was approved at the Scottish skin cancer meeting in March 2025 and is accessible within NHS Scotland through local cancer networks. These guidelines recommend initiating MCC treatment within 8 weeks from diagnosis to improve patient outcomes, representing the first UK-based guideline for MCC. The development process and final guideline, aligned with the RIGHT checklist, aimed at enhancing the multidisciplinary management of MCC in the NHS.

Keywords: Guidelines; Merkel Cell Cancer; Multidisciplinary; Skin cancer; UK.