Merkel cell carcinoma (MCC) is a cutaneous malignancy often treated with surgical resection followed by adjuvant radiation therapy (RT). In the node-positive setting, adjuvant RT reduces the risk of locoregional recurrence, but historical data suggest that distant failure is a persistent issue and often fatal. This has prompted new efforts to intensify treatment in these patients with the addition of neoadjuvant or adjuvant immune checkpoint inhibitor therapy. However, newer diagnostic techniques have led to stage migration in patients with previously subclinical metastatic disease; consequently, preventing locoregional recurrence may be a higher priority in node-positive MCC patients than was previously believed. Recent trials in node-positive MCC, such as ADMEC-O, have had lower rates of adjuvant RT utilization in treatment versus control arms, which may have attenuated the observed effect of adjuvant immunotherapy. The low utilization of adjuvant RT may have also resulted in a higher recurrence rate in patients who did not have a complete response to neoadjuvant immunotherapy in the CHECKMATE 358 trial. Altogether, these are important considerations for ongoing and future immunotherapy trials in MCC and may affect the interpretation of their results. Ongoing clinical trials may determine which patients are at low risk of recurrence when treated with immunotherapy and whether adjuvant RT could be omitted in select patients.
默克尔细胞癌（MCC）是一种皮肤恶性肿瘤，通常采用手术切除联合辅助放射治疗（RT）进行治疗。在淋巴结阳性情况下，辅助放疗可降低局部区域复发的风险，但历史数据表明远处转移仍是持续存在的问题且常致命。这促使人们通过增加新辅助或辅助免疫检查点抑制剂治疗来加强这些患者的治疗力度。然而，新的诊断技术导致既往亚临床转移性疾病患者出现分期迁移；因此，预防局部区域复发在淋巴结阳性MCC患者中可能比以往认为的更为重要。近期针对淋巴结阳性MCC的试验（如ADMEC-O）显示，治疗组中辅助放疗的使用率低于对照组，这可能削弱了辅助免疫疗法观察到的效果。在CHECKMATE 358试验中，辅助放疗的低使用率也可能导致对新辅助免疫疗法未完全缓解的患者复发率更高。总之，这些是当前及未来MCC免疫疗法试验中需重点考虑的因素，并可能影响对其结果的解读。正在进行的临床试验或将确定哪些患者在接受免疫疗法治疗后复发风险较低，以及是否可在特定患者中省略辅助放疗。
肿瘤(癌症)患者之家