Kim Seijong, Kim Eun Ran, Hong Sung Noh, Chang Dong Kyung, Kim Young-Ho, Shin Jung Kyong, Park Yoonah, Huh Jung Wook, Kim Hee Cheol, Yun Seong Hyeon, Lee Woo Yong, Cho Yong Beom
Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Division of Gastroenterology, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Dig Endosc. 2025 Sep;37(9):962-971. doi: 10.1111/den.15056. Epub 2025 Jun 10.
This study aimed to identify risk factors for recurrence of rectal neuroendocrine neoplasms, establish a cut-off size for recurrence prediction, and standardize surveillance guidelines.
This retrospective study analyzed patients diagnosed with rectal neuroendocrine neoplasm at Samsung Medical Center from January 2007 to July 2021. Tumors were classified according to World Health Organization and European Neuroendocrine Tumor Society guidelines. The primary outcome was to determine the ideal cut-off size for predicting recurrence.
A total of 1011 patients (median follow-up: 58 months) were included: 967 with grade (G) I neuroendocrine tumor (NET), 35 with GII NET, and 9 with neuroendocrine carcinoma. Disease-free and overall survival were significantly better in GI NET than in GII and neuroendocrine carcinoma. For NET G1 patients undergoing endoscopic resection, a 0.7 cm cut-off (area under the curve = 0.94) showed 100% sensitivity, 79% specificity, and no recurrence. In contrast, for lymphovascular invasion (LVI)-positive, lymph node-negative NET G1 patients undergoing transanal endoscopic microsurgery/transanal excision or radical resection, an optimal cut-off of 1.5 cm (area under the curve = 0.92) was identified. NET G2 had a 22.9% lymph node metastasis rate, with recurrence risk increasing with size.
For NET G1 tumors ≤0.7 cm without LVI following endoscopic resection, routine surveillance may not be necessary due to the minimal risk of recurrence. Similarly, for LVI-positive, lymph node-negative NET G1 tumors that underwent surgical resection, surveillance may not be required if the tumor is ≤1.5 cm. Additionally, NET G2 tumors require regular follow-up regardless of size to ensure favorable oncologic outcomes. These findings contribute to a risk-based approach for surveillance, optimizing follow-up strategies.
本研究旨在确定直肠神经内分泌肿瘤复发的危险因素，建立用于复发预测的临界大小，并规范监测指南。
这项回顾性研究分析了2007年1月至2021年7月在三星医疗中心被诊断为直肠神经内分泌肿瘤的患者。肿瘤根据世界卫生组织和欧洲神经内分泌肿瘤学会指南进行分类。主要结果是确定预测复发的理想临界大小。
共纳入1011例患者（中位随访时间：58个月）：967例为I级（G）神经内分泌肿瘤（NET），35例为GII级NET，9例为神经内分泌癌。GI级NET的无病生存期和总生存期明显优于GII级和神经内分泌癌。对于接受内镜切除的NET G1患者，0.7厘米的临界值（曲线下面积=0.94）显示出100%的敏感性、79%的特异性且无复发。相比之下，对于接受经肛门内镜显微手术/经肛门切除术或根治性切除术的淋巴管侵犯（LVI）阳性、淋巴结阴性的NET G1患者，确定的最佳临界值为1.5厘米（曲线下面积=0.92）。NET G2的淋巴结转移率为22.9%，复发风险随肿瘤大小增加。
对于内镜切除后直径≤0.7厘米且无LVI的NET G1肿瘤，由于复发风险极小，可能无需常规监测。同样，对于接受手术切除的LVI阳性、淋巴结阴性的NET G1肿瘤，如果肿瘤直径≤1.5厘米，可能也无需监测。此外，无论肿瘤大小，NET G2肿瘤都需要定期随访以确保良好的肿瘤学结局。这些发现有助于基于风险的监测方法，优化随访策略。
