Despite previously reported treatment strategies for nonfunctioning small (≤20 mm) pancreatic neuroendocrine neoplasms (pNENs), uncertainties persist. We aimed to evaluate the surgically resected cases of nonfunctioning small pNENs (NF-spNENs) in a large Japanese cohort to elucidate an optimal treatment strategy for NF-spNENs. In this Japanese multicenter study, data were retrospectively collected from patients who underwent pancreatectomy between January 1996 and December 2019, were pathologically diagnosed with pNEN, and were treated according to the World Health Organization 2019 classification. Overall, 1490 patients met the eligibility criteria, and 1014 were included in the analysis cohort. In the analysis cohort, 606 patients (59.8%) had NF-spNENs, with 82% classified as grade 1 (NET-G1) and 18% as grade 2 (NET-G2) or higher. The incidence of lymph node metastasis (N1) by grade was significantly higher in NET-G2 (G1: 3.1% vs G2: 15.0%). Independent factors contributing to N1 were NET-G2 or higher and tumor diameter ≥15 mm. The predictive ability of tumor size for N1 was high. Independent factors contributing to recurrence included multiple lesions, NET-G2 or higher, tumor diameter ≥15 mm, and N1. However, the independent factor contributing to survival was tumor grade (NET-G2 or higher). The appropriate timing for surgical resection of NET-G1 and NET-G2 or higher was when tumors were >20 and >10 mm, respectively. For neoplasms with unknown preoperative grades, tumor size >15 mm was considered appropriate. NF-spNENs are heterogeneous with varying levels of malignancy. Therefore, treatment strategies based on tumor size alone can be unreliable; personalized treatment strategies that consider tumor grading are preferable.

中文翻译：

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影响无功能小胰腺神经内分泌肿瘤的因素及新的治疗策略


尽管之前报道了无功能的小（≤20毫米）胰腺神经内分泌肿瘤（pNEN）的治疗策略，但不确定性仍然存在。我们的目的是评估日本大型队列中手术切除的无功能小 pNEN (NF-spNEN) 病例，以阐明 NF-spNEN 的最佳治疗策略。在这项日本多中心研究中，回顾性收集了1996年1月至2019年12月期间接受胰腺切除术、病理诊断为pNEN并根据世界卫生组织2019年分类进行治疗的患者的数据。总体而言，1490 名患者符合资格标准，其中 1014 名患者被纳入分析队列。在分析队列中，606 名患者 (59.8%) 患有 NF-spNEN，其中 82% 为 1 级 (NET-G1)，18% 为 2 级 (NET-G2) 或更高级别。 NET-G2中按级别划分的淋巴结转移（N1）发生率显着较高（G1：3.1% vs G2：15.0%）。促成 N1 的独立因素为 NET-G2 或更高且肿瘤直径≥15 mm。肿瘤大小对 N1 的预测能力较高。导致复发的独立因素包括多个病灶、NET-G2或更高、肿瘤直径≥15 mm和N1。然而，影响生存的独立因素是肿瘤等级（NET-G2 或更高）。 NET-G1和NET-G2或更高级别手术切除的合适时机是当肿瘤分别>20和>10mm时。对于术前分级未知的肿瘤，肿瘤大小>15 mm被认为是合适的。 NF-spNEN 是异质的，具有不同程度的恶性程度。因此，仅基于肿瘤大小的治疗策略可能不可靠。考虑肿瘤分级的个性化治疗策略是优选的。