Utility of Preoperative Staging for Clinically Localized Merkel Cell Carcinoma

Introduction: For Merkel Cell Carcinoma (MCC), a rare cutaneous neuroendocrine cancer, treatment varies based on disease stage at presentation. For patients with localized disease, primary treatment is surgical resection. There is wide practice variation in the performance of preoperative imaging studies, which may upstage patients and/or change plans for surgical resection. The purpose of this study was to evaluate how preoperative staging with cross-sectional imaging influenced management of patients with clinically localized Merkel Cell Carcinoma. Methods: We identified patients who were evaluated at our facility between January 1, 2012 and December 31, 2020 for clinically localized MCC (confined to the skin, without evidence of nodal spread or signs/symptoms of distant disease) prior to surgical resection. The primary outcome was the proportion of patients whose management changed based on preoperative imaging. Results: There were 97 patients, of whom 84 (87%) had preoperative staging studies. Patients had a median age of 75 years, 13% were immunosuppressed, and 81% had tumors <2cm. There were no differences in the clinical characteristics of patient based on whether staging was performed. PET/CT was performed in 52(67%) patients, 51(62%) CT, 31(41%) brain MRI. There were 5 patients with indeterminate findings (all on PET/CT), but there were no patients for whom preoperative staging changed the plan for surgical resection. Conclusion: There were no changes in surgical management based on results of preoperative imaging. More selective use of preoperative imaging staging may be warranted, potentially considering risk factors for clinically occult micro-metastatic disease.