Abstract：
Merkel cell carcinoma (MCC) is a rare, highly aggressive cutaneous neuroendocrine carcinoma. Controversy exists regarding optimal management of MCC as high-quality randomized studies and clinical trials are limited, and physicians are bound to interpret highly heterogeneous, retrospective literature in their clinical practice. Furthermore, the rising incidence and notably poor prognosis of MCC urges the establishment of best practices for optimal management of the primary tumor and its metastases. Herein, we summarized the relevant evidence and provided an algorithm for decision-making in MCC management based on the latest 2021 National Comprehensive Cancer Network guidelines. Additionally, we report current active MCC clinical trials in the United States. The initial management of MCC is dependent upon the pathology of the primary tumor and presence of metastatic disease. Patients with no clinical evidence of regional lymph node involvement generally require sentinel node biopsy (SLNB) while clinically node-positive patients should undergo fine needle aspiration (FNA) or core biopsy and full imaging workup. If SLNB or FNA/core biopsy are positive, a multidisciplinary team should be assembled to discuss if additional node dissection or adjuvant therapy is necessary. Wide local excision is optimal for primary tumor management and SLNB remains the preferred staging and predictive tool in MCC. The management of MCC has progressively improved in the last decade, particularly due to the establishment of immunotherapy as a new treatment option in advanced MCC. Ongoing trials and prospective studies are needed to further establish the best practices for MCC management.
摘要：
默克尔细胞癌(MCC)是一种罕见的，高度侵袭性皮肤神经内分泌癌。关于MCC的最佳管理存在争议，因为高质量的随机研究和临床试验有限，医生必然会解释高度异质的，临床实践中的回顾性文献。此外，MCC的发病率不断上升,预后明显较差,这促使人们建立最佳的治疗方法,以优化原发性肿瘤及其转移.在这里，我们根据最新的2021年国家综合癌症网络指南,总结了相关证据,并为MCC管理提供了决策算法.此外,我们报道了美国目前正在进行的MCC临床试验.MCC的初始管理取决于原发性肿瘤的病理学和转移性疾病的存在。没有临床证据表明区域淋巴结受累的患者通常需要前哨淋巴结活检（SLNB），而临床淋巴结阳性的患者应进行细针穿刺（FNA）或核心活检和全面的影像学检查。如果SLNB或FNA/核心活检阳性，应组建一个多学科小组,讨论是否需要额外的淋巴结清扫或辅助治疗.广泛的局部切除是原发性肿瘤治疗的最佳选择，而SLNB仍然是MCC中首选的分期和预测工具。在过去十年中，MCC的管理逐步改善，特别是由于免疫疗法作为晚期MCC的新治疗选择的确立。需要持续的试验和前瞻性研究来进一步建立MCC管理的最佳实践。
