Department of Experimental Diagnostic and Specialized Medicine (DIMES), Alma Mater Studiorum, University of Bologna, Bologna, Italy.
Division of Medical Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy.
Cancer Med. 2022 Nov;11(22):4204-4213. doi: 10.1002/cam4.4773. Epub 2022 Apr 29.
After radical resection of a nonmetastatic Merkel cell carcinoma (M0 MCC), postoperative radiation therapy (RT) is recommended as it improves survival. However, the role of RT in specific subgroups of M0 MCC is unclear. We sought to identify whether there is a differential survival benefit from RT in specific M0 MCC patient subgroups.
M0 MCC patients from the Surveillance, Epidemiology, and End Results (SEER) database registry were collected. The best prognostic age, tumor size, and lymph node ratio (LNR, ratio between positive lymph nodes and resected lymph nodes) cutoffs were calculated. The primary endpoint was overall survival (OS).
A total of 5644 M0 MCC patients (median age 77 years, 62% male) were included: 4022 (71%) node-negative (N0) and 1551 (28%) node-positive (N+). Overall, 2682 patients (48%) received RT. Age > 76.5 years, tumor size >13.5 mm, and LNR >0.215 were associated with worse OS. RT was associated with longer OS in the M0 MCC, N0, and N+ group and independently associated with a 25%, 27%, and 26% reduction in the risk for death, respectively. RT benefit on survival was increased in tumor size >13.5 mm in the N0 group and LNR >0.215 in the N+ group. No OS benefit from RT was observed in T4 tumors (N0 and N+ groups).
RT was associated with improved survival in M0 MCC, irrespective of the nodal status. LNR >0.215 is a useful prognostic factor for clinical decision-making and for stratification and interpretation of clinical trials.
非转移性 Merkel 细胞癌（M0 MCC）根治性切除术后，建议行术后放疗（RT），因为它可以提高生存率。然而，RT 在 M0 MCC 特定亚组中的作用尚不清楚。我们旨在确定 RT 是否对 M0 MCC 特定患者亚组的生存有不同的获益。
从监测、流行病学和最终结果（SEER）数据库中收集 M0 MCC 患者数据。计算最佳预后年龄、肿瘤大小和淋巴结比值（LNR，阳性淋巴结与切除淋巴结的比值）截断值。主要终点是总生存率（OS）。
共纳入 5644 例 M0 MCC 患者（中位年龄 77 岁，62%为男性）：4022 例（71%）为淋巴结阴性（N0），1551 例（28%）为淋巴结阳性（N+）。总体而言，2682 例（48%）患者接受了 RT。年龄>76.5 岁、肿瘤直径>13.5mm 和 LNR>0.215 与较差的 OS 相关。RT 与 M0 MCC、N0 和 N+ 患者的 OS 延长相关，且独立降低死亡风险分别为 25%、27%和 26%。在 N0 组中，肿瘤直径>13.5mm 和在 N+组中，LNR>0.215 时，RT 对生存的获益增加。在 N0 和 N+组中，T4 肿瘤（无淋巴结转移和淋巴结转移）未观察到 RT 对 OS 的获益。
RT 与 M0 MCC 患者的生存改善相关，无论淋巴结状态如何。LNR>0.215 是一个有用的预后因素，可用于临床决策制定以及分层和解释临床试验。
