直肠神经内分泌肿瘤（NETs）的发病率持续增长。本回顾性、单中心研究分析了195例行根治性手术的 I-III 期直肠 NET 患者的淋巴结（LN）转移危险因素和预后影响。此研究重点分析先前确认的危险因素和一项新危险因素：多发直肠 NET。还分析了 LN 转移与预后的关联。病理学上，LN 转移率（也是 III 期疾病率）为 39%，高于临床 LN 转移率的 14%。肿瘤大小 >10 毫米、中央凹陷存在、肿瘤级别为 G2、侵袭深度、术前影像学显示的 LN 肿大（cN1）、静脉侵犯和多发 NETs 被确定为 LN 转移的危险因素。随着肿瘤大小和危险因素的增加，LN 转移率也增加。其中静脉侵犯、cN1 和多发 NETs 被确认为 LN 转移的独立预测因子。直肠 NETs 的 LN 转移与疾病无瘤期及疾病特异性生存率显著不良相关。随着危险因素的增加，直肠 NETs 转移到 LN 的潜力增加，LN 转移与不良预后相关。这是第一项报道多发 NETs 是 LN 转移危险因素的研究。未来的研究应比较全切手术与局部切除对 LN 清扫的生存效益。© 2023年。外科肿瘤学会。

The incidence of rectal neuroendocrine tumors (NETs) has been steadily increasing. The risk factors for and prognostic impact of lymph node (LN) metastasis were analyzed in 195 patients with stage I-III rectal NET who underwent radical surgery.This retrospective, single-center study analyzed risk factors for LN metastasis focusing on previously identified factors and a novel risk factor: multiple rectal NETs. The association between LN metastasis and the prognosis was also analyzed.Pathologically, the LN metastasis rate (also the rate of stage III disease) was 39%, which was higher than the clinical LN metastasis rate of 14%. Tumor size > 10 mm, presence of central depression, tumor grade G2, depth of invasion, LN swelling on preoperative imaging (cN1), venous invasion and multiple NETs were identified as risk factors for LN metastasis. As the tumor size and risk factors increased, the rate of LN metastasis increased. Among these 7 factors, venous invasion, cN1, and multiple NETs were identified as independent predictors of LN metastasis. LN metastasis of rectal NETs was associated with significantly poor disease-free and disease-specific survival.As risk factors increase, the potential for rectal NETs to metastasize to the LNs increases and LN metastasis is associated with a poor prognosis. This is the first study to report multiple NETs as a risk factor for LN metastasis. A future study examining the survival benefit of radical surgery accompanying LN dissection compared with local resection is warranted.© 2023. Society of Surgical Oncology.