大约 50% 的默克尔细胞癌 (MCC) 患者可检测到默克尔癌蛋白 (AMERK) 血清抗体，可用于监测复发情况。本研究的目的是表征接受 MCC 治疗性放射治疗 (RT) 的患者的 AMERK 水平，并确定 AMERK 与复发之间的关联。这是一项针对 MCC 患者的回顾性研究，这些患者在接受治疗前进行了基线 AMERK 测量。 2010 年至 2020 年的意向 RT。使用 Kaplan-Meier 方法和 Cox 回归计算无事件生存期 (EFS)。通过死亡作为竞争风险和格雷检验来分析 MCC 相关复发 (CIMR) 的累积发生率。作者确定了 88 名进行基线 AMERK 测量的患者，其中 52 名 (59%) 具有可检测水平。 AMERK 阳性与较年轻的中位年龄（67.8 岁对比 72.0 岁；p = 0.02）和肿瘤部位（p = 0.02）相关，头颈部患病者的阳性率较低（17.3% 对比 44.4%） ）。 EFS（71.3% vs. 60.4%；p = .30）和 CIMR（24.4% vs. 39.6%；p = .23）在 AMERK 阳性患者中更为有利。两名患者在放疗野出现复发，且基线时均为 AMERK 阴性。 RT 后达到 AMERK 最低点的中位时间为 11.2 个月；并且，在 RT 后 6 个月的标志性分析中，AMERK 阳性患者转为阴性或水平下降 ≥ 50% 的患者比例与 EFS 无关（87.1% 对比 85.0%；p = .90) 或 CIMR (12.9% vs. 15.0%; p = .62)。阳性 AMERK 基线水平与 MCC 诊断时的年轻年龄和非头颈肿瘤位置相关，可能与病毒病原学的分布有关。无法确定与 EFS 相关的特定 RT 后 AMERK 下降。© 2024 美国癌症协会。

Serum antibodies to the Merkel oncoprotein (AMERK) are detectable in approximately 50% of patients with Merkel cell carcinoma (MCC) and can be used to monitor for recurrence. The objective of this study was to characterize AMERK levels in patients receiving curative-intent radiation therapy (RT) for MCC and identify associations between AMERK and recurrence.This was a retrospective study of patients with MCC who had baseline AMERK measurements before they received curative-intent RT from 2010 to 2020. Event-free survival (EFS) was calculated using the Kaplan-Meier method and Cox regression. The cumulative incidence of MCC-related recurrence (CIMR) was analyzed with death as a competing risk and the Gray test.The authors identified 88 patients who had baseline AMERK measurements, including 52 (59%) with detectable levels. AMERK positivity was associated with younger median age (67.8 vs. 72.0 years; p = .02) and tumor site (p = 0.02), with lower rates for those who had disease in the head/neck region (17.3% vs. 44.4%). EFS (71.3% vs. 60.4%; p = .30) and CIMR (24.4% vs. 39.6%; p = .23) were more favorable in AMERK-positive patients. Two patients had recurrences in the RT field, and both were AMERK-negative at baseline. The median time to AMERK nadir after RT was 11.2 months; and, in a 6-month post-RT landmark analysis, the proportion of patients who were AMERK-positive who became negative or who had levels that decreased by ≥50% were not associated with EFS (87.1% vs. 85.0%; p = .90) or CIMR (12.9% vs. 15.0%; p = .62).Positive AMERK baseline levels were correlated with younger age at MCC diagnosis and nonhead and neck tumor location, possibly related to the distribution of viral etiology. A specific post-RT AMERK decline correlating with EFS could not be identified.© 2024 American Cancer Society.