Duodenal neuroendocrine tumors: Impact of tumor size and total number of lymph nodes examined

Abstract

Background The current study sought to investigate the impact of tumor size and total number of LN examined (TNLE) on the incidence of lymph node metastasis (LNM) among patients with duodenal neuroendocrine tumor (dNET). Methods Patients who underwent curative resection for dNETs between 1997‐2016 were identified from 8 high‐volume US centers. Risk factors associated with overall survival and LNM were identified and the optimal cut‐off of TNLE relative to LNM was determined. Results Among 162 patients who underwent resection of dNETs, median patient age was 59 (interquartile range [IQR], 51‐68) years and median tumor size was 1.2 cm (IQR, 0.7‐2.0 cm); a total of 101 (62.3%) patients underwent a concomitant LND at the time of surgery. Utilization of lymphadenectomy (LND) increased relative to tumor size (≤1 cm:52.2% vs 1‐2 cm:61.4% vs >2 cm:93.8%; P < .05). Similarly, the incidence of LNM increased with dNET size (≤1 cm: 40.0% vs 1‐2 cm:65.7% vs >2 cm:80.0%; P < .05). TNLE ≥ 8 had the highest discriminatory power relative to the incidence of LNM (area under the curve = 0.676). On multivariable analysis, while LNM was not associated with prognosis (hazard ratio [HR] = 0.9; 95% confidence intervals [95%CI], 0.4‐2.3), G2/G3 tumor grade was (HR = 1.5; 95%CI, 1.0‐2.1). Conclusions While the incidence of LNM directly correlated with tumor size, patients with dNETs ≤ 1 cm had a 40% incidence of LNM. Regional lymphadenectomy of a least 8 LN was needed to stage patients accurately.

Duodenal, ampullary, and pancreatic neuroendocrine tumors: Oncologic outcomes are driven by tumor biology and tissue of origin

“…Similarly, survival in patients with duodenal NETs, the presence of lymph node involvement has had conflicting results. Some have suggested that the presence of lymph node involvement contributes to a worse prognosis 17,23 while numerous others have shown that lymph node metastases do not appear to impact survival 1,18,19,34 . This latter assertion was seen in the IS‐NET group as there was no difference in RFS or OS for patients that had lymph node involvement.…”

“…The rate of lymph node involvement in the literature ranges from 46% to 88% 1,7,25‐28 for ampullary and 26%–82% for duodenal NETs 1,2,17,28‐32 . Ampullary histology, 16,33 grade, 25 increasing tumor size (>1.5–2 cm), 2,19,34 and depth of invasion 32 have all been demonstrated to be positive predictors of lymph node metastases. In our study, there was a significant difference in the rate of lymph node involvement between tumors arising in disparate locations (86.7% ampullary, 71.0% duodenal, and 42.2% pancreas).…”

“…Previous small series have demonstrated similar disease free survival rates for ampullary NETs of 56% at 3 years 33 and 66% and 5 years, 8 with population level data demonstrating 5 and 10 year OS of 82% and 71% 25 . Reported 5‐year RFS and OS rates for duodenal NETs are 81% 18 and 66%–94%, 1,8,19,31,35 respectively. In addition, median OS of 187 months 29 and disease free survival of 156 months has been reported for duodenal NETs 17 .…”

“…The rare nature of this disease is highlighted by population‐level data analysis in which only 120 patients were identified 16 . The breadth of the literature suggests that even though duodenal NETs tend to be small on presentation, there is a significant risk of lymph node involvement (40%–80% of cases) 1,2,17‐19 . Some subtypes, such as gastrinoma, may even present with occult primaries in the setting of bulky nodal disease 20 .…”

How to Choose the Best Procedure Type for Duodenal Neuroendocrine Tumors With a Maximum Diameter of 1 to 2 Cm a Propensity Score Matching Analysis Based on the SEER Database

“…Therefore, duodenal endoscopic submucosal dissection is truly challenging, and even Japanese experts think twice before indicating [11], because there are risks of bleeding, perforation, positive margins, and missed metastatic lymph nodes in endoscopic resection treatment [8,9,[12][13][14][15][16]. Some studies reported that the lymphatic metastasis rate of d-NET with a tumor of 1-2 cm in diameter was approximately 60% [17,18]. Our data showed that among the 286 patients included, the T2 rate was 61.19%, which was the highest, the T3 + rate was 11.54%, and the total lymph node positive rate was 22.03%, which included 35.9% of the radical resection group and 4.62% of the local resection group.…”