Surgical resection for duodenal neuroendocrine neoplasia: Outcome, prognostic factors and risk of metastases

Prevalence and risk factors for lymph node metastasis in duodenal neuroendocrine tumors: a systematic review and meta-analysis

BACKGROUND

Although the status of lymph node metastasis (LNM) is crucial in determining treatment strategy for duodenal neuroendocrine tumors (D-NETs), robust evidence for their potential LNM risk remains lacking. This systematic review aimed to summarize the prevalence and risk factors of LNM in D-NETs.

METHODS

This systematic review of electronic databases identified eligible case-control and cohort studies for D-NET resected either endoscopically or surgically, published from 1990 to 2023. The primary outcome was the pooled prevalence of LNM in D-NETs. Secondary outcomes included the pooled prevalence of LNM according to tumor location and functionality, as well as identifying pathological risk factors for LNM. Meta-analysis was performed.

RESULTS

We identified 36 studies that involved 1,396 patients with D-NETs, including 326 with LNM. The pooled prevalence of LNM in D-NETs was 22.7% (95% confidence interval [CI] 17.3-29.2%). The prevalence was high in ampullary/peri-ampullary D-NETs and functional D-NETs (46.8 and 53.3%, respectively), whereas it was low in non-functional, non-ampullary D-NETs (NAD-NETs) (9.5%). Pathological risk factors for LNM in NAD-NETs included tumor size > 10 mm (odds ratio [OR] 7.31 [95% CI 3.28-16.31]), tumor invasion into the muscularis propria or deeper (OR 7.79 [3.65-16.61]), lymphovascular invasion (OR 5.67 [2.29-14.06]), and World Health Organization grading of G2 (OR 2.47 [1.03-5.92]).

CONCLUSION

Approximately one-fourth of the patients with D-NETs had LNM. Endoscopic resection might be acceptable for non-functional NAD-NETs with diameters of 10 mm or less, but additional surgical resection with lymphadenectomy may be recommended for cases exhibiting pathological risk factors.

Clinicopathological Correlates of Hormone Expression-Based Subtypes of Non-Functioning Duodenal/Ampullary Neuroendocrine Tumors: A Multicenter Study of 151 Cases

Duodenal neuroendocrine tumors (Duo-NETs) may arise in the ampullary and non-ampullary duodenum. Non-functioning Duo-NETs (NF-Duo-NETs), which account for most cases, may express various hormones. Previous studies have suggested that hormone production might be associated with biological aggressiveness. Current treatment protocols are based on functionality, tumor size, and location, but small NF-Duo-NETs may also have metastatic potential. We aimed to investigate whether tumor cell subtyping, based on hormone expression, could provide further insights into NF-Duo-NET biological behavior. We analyzed the clinico-pathological correlates of hormone expression in a multicenter series of 151 NF-Duo-NETs, subdividing tumors into five subtypes: gastrin-producing G-cell NETs (Gas-NETs), somatostatin-producing D-cell NETs (Som-NETs), serotonin-producing enterochromaffin-cell NETs (Ser-NETs), plurihormonal NETs, and gastrin-, somatostatin-, and serotonin-negative NETs (GSSN-NETs). Som-NETs were the most frequent (31%), followed by plurihormonal NETs (26%), Gas-NETs (24%), GSSN-NETs (13%), and Ser-NETs (4%). Som-NETs and GSSN-NETs were more commonly located in the ampullary region and showed significantly larger size, more frequent lymphatic and/or vascular invasion, and higher pT, pN, and American Joint Committee on Cancer (AJCC-9th edition) stages compared to Gas-NETs, which were often (77%) diagnosed at AJCC stage I. Ampullary Som-NETs showed a more invasive and metastatic potential compared to non-ampullary Som-NETs, while, among plurihormonal NETs, the predominantly expressed hormone influenced tumor biological features, with gastrin-predominant NETs showing less invasive potential. At logistic regression, both tumor cell subtype and tumor size were independently associated with aggressiveness (pT3, pN1, or pM1 stage at diagnosis). Hormonal expression profiling may be clinically relevant in NF-Duo-NETs, independently of tumor size.

Duodenal neuroendocrine neoplasms on enhanced CT: establishing a diagnostic model with duodenal gastrointestinal stromal tumors in the non-ampullary area and analyzing the value of predicting prognosis

OBJECTIVE

To identify CT features and establish a diagnostic model for distinguishing non-ampullary duodenal neuroendocrine neoplasms (dNENs) from non-ampullary duodenal gastrointestinal stromal tumors (dGISTs) and to analyze overall survival outcomes of all dNENs patients.

MATERIALS AND METHODS

This retrospective study included 98 patients with pathologically confirmed dNENs (n = 44) and dGISTs (n = 54). Clinical data and CT characteristics were collected. Univariate analyses and binary logistic regression analyses were performed to identify independent factors and establish a diagnostic model between non-ampullary dNENs (n = 22) and dGISTs (n = 54). The ROC curve was created to determine diagnostic ability. Cox proportional hazards models were created and Kaplan-Meier survival analyses were performed for survival analysis of dNENs (n = 44).

RESULTS

Three CT features were identified as independent predictors of non-ampullary dNENs, including intraluminal growth pattern (OR 0.450; 95% CI 0.206-0.983), absence of intratumoral vessels (OR 0.207; 95% CI 0.053-0.807) and unenhanced lesion > 40.76 HU (OR 5.720; 95% CI 1.575-20.774). The AUC was 0.866 (95% CI 0.765-0.968), with a sensitivity of 90.91% (95% CI 70.8-98.9%), specificity of 77.78% (95% CI 64.4-88.0%), and total accuracy rate of 81.58%. Lymph node metastases (HR: 21.60), obstructive biliary and/or pancreatic duct dilation (HR: 5.82) and portal lesion enhancement ≤ 99.79 HU (HR: 3.02) were independent prognostic factors related to poor outcomes.

CONCLUSION

We established a diagnostic model to differentiate non-ampullary dNENs from dGISTs. Besides, we found that imaging features on enhanced CT can predict OS of patients with dNENs.

Optimal surgical approach for digestive neuroendocrine neoplasia primaries: Oncological benefits versus short and long-term complications

The rising incidence and the accumulating prevalence of neuroendocrine neoplasia (NEN) in the population makes this a common, prevalent and a clinically relevant disease group. Surgical resection represents the only potentially curative treatment for digestive NENs. Thus, resection should in principle be considered for all patients with NEN, although taking the patients age, relevant comorbidity, and performance status into account for operability. Patients with insulinomas, NEN of the appendix and rectal NENs are usually cured by surgery alone. However, less than a third of patients are amendable to curative surgery alone at time of diagnosis. Furthermore, recurrence is common and may occur years after primary surgery, hence the long follow-up time recommended in most NENs (>10 years). As many patients with NENs present with locoregional or metastatic disease, there is considerable debate regarding the role of debulking surgery in these settings. However, good long-term survival can be achieved in a considerable proportion of patients, with 50-70% alive up to 10 years after surgery. Location and grade are the main determinants of long-term survival. Here we present considerations to surgery for primary neuroendocrine tumors in the digestive tract.

Ampullary Neuroendocrine Neoplasms: Identification of Prognostic Factors in a Multicentric Series of 119 Cases

Neuroendocrine neoplasms (NENs) of the major and minor ampulla are rare diseases with clinico-pathologic features distinct from non-ampullary-duodenal NENs. However, they have been often combined and the knowledge on prognostic factors specific to ampullary NENs (Amp-NENs) is limited. The aim of this study was to identify factors associated with metastatic potential and patient prognosis in Amp-NENs. We clinically and histologically investigated an international series of 119 Amp-NENs, comprising 93 ampullary neuroendocrine tumors (Amp-NETs) and 26 neuroendocrine carcinomas (Amp-NECs). Somatostatin-producing tubulo-acinar NET represented the predominant Amp-NET histologic subtype (58 cases, 62%, 12 associated with type 1 neurofibromatosis). Compared to Amp-NETs, Amp-NECs arose in significantly older patients and showed a larger tumor size, a more frequent small vessel invasion, a deeper level of invasion and a higher rate of distant metastasis, and, importantly, a tremendously worse disease-specific patient survival. In Amp-NETs, the WHO grade proved to be a strong predictor of disease-specific survival (hazard ratio: 12.61, p < 0.001 for G2 vs G1), as well as patient age at diagnosis > 60 years, small vessel invasion, pancreatic invasion, and distant metastasis at diagnosis. Although nodal metastatic disease was not associated with survival by itself, patients with > 3 metastatic lymph nodes showed a worse outcome in comparison with the remaining Amp-NET cases with lymphadenectomy. Tumor epicenter in the major ampulla, small vessel invasion, and tumor size > 16 mm were independent predictors of nodal metastases in Amp-NETs. In conclusion, we identified prognostic factors, which may eventually help guide treatment decisions in Amp-NENs.

Management of Duodenal Neuroendocrine Tumors: Surgical versus Endoscopic Mucosal Resection

BACKGROUND

Management of duodenal neuroendocrine tumors (DNETs) is not standardized, with smaller lesions (< 1-2 cm) generally treated by endoscopic mucosal resection (EMR) and larger DNETs by surgical resection (SR). This study reviewed how patients were selected for treatment and compared outcomes.

PATIENTS AND METHODS

Patients with DNETs undergoing resection were identified through institutional databases, and clinicopathologic data recorded. χ² and Wilcoxon tests compared variables. Survival was determined by Kaplan-Meier, and Cox regression tested association with survival.

RESULTS

Among 104 patients, 64 underwent EMR and 40 had SR. Patients selected for SR had larger tumor size, younger age, and higher T, N, and M stage. There was no difference in progression-free (PFS) or overall survival (OS) between SR and EMR. In 1-2 cm DNETs, there was no difference in PFS between SR and EMR [median not reached (NR), P = 0.1]; however, longer OS was seen in SR (median NR versus 112 months, P = 0.03). In 1-2 cm DNETs, SR patients were more likely to be node-positive and younger. After adjustment for age, resection method did not correlate with survival. Comparison of surgically resected DNETs versus jejunoileal NETs revealed longer PFS (median NR versus 73 months, P < 0.001) and OS (median NR versus 119 months, P = 0.004) DISCUSSION: In 1-2 cm DNETs, there was no difference in survival between EMR and SR after adjustment for age. Recurrences could be salvaged, suggesting that EMR is a reasonable strategy. Compared with jejunoileal NETs, DNETs treated by SR had improved PFS and OS.

Clinical outcomes of cap-assisted endoscopic resection for small rectal subepithelial tumors

OBJECTIVE

To assess the effectiveness and safety of cap-assisted endoscopic resection and the usefulness of endoscopic ultrasonography (EUS) for managing small rectal subepithelial tumors (SETs).

PATIENTS AND METHODS

Patients with small rectal SETs≤10mm in diameter were enrolled in this study at our hospital from October 2014 to December 2017. First, EUS was performed to evaluate the lesions. Then, cap-assisted endoscopic resection was performed by suctioning the SET into a transparent cap, ligating with a metal snare and then resecting the tumor. The wound was closed using endoclips if necessary.

RESULTS

Forty patients were enrolled in the study. EUS showed lesions originating from muscularis mucosa or submucosa with an average diameter of 5.4×3.1mm. The en bloc resection rate was 85.0% obtained by cap-assisted endoscopic resection, with a mean total procedure time of 17.6min. No immediate perforation happened. Immediate bleeding occurred in five patients; all cases were managed successfully by endoscopy. No delayed bleeding was observed. Pathology examination showed that 70.0% of the lesions were neuroendocrine tumors (G1). One case of recurrence was seen in follow-up; it was managed successfully by endoscopic submucosal dissection. There was no tumor recurrence in a median follow-up period of 41 months in the remaining 39 patients.

CONCLUSIONS

Most small rectal SETs arising from the muscularis mucosa or submucosa are neuroendocrine tumors and require proper treatment. Cap-assisted endoscopic resection is simple, effective and safe for resecting such lesions, and EUS is useful for case screening.

Risk factors for lymph node metastasis and survival of patients with nonampullary duodenal carcinoid tumors treated with endoscopic therapy versus surgical resection: analysis of the Surveillance, Epidemiology, and End Results program

BACKGROUND AND AIMS

Endoscopic therapy (ET) has been used to treat nonampullary duodenal neuroendocrine tumors (NAD-NETs) ≤10 mm in size, but data on long-term outcomes are limited. In addition, management of 11- to 19-mm NAD-NETs is not well defined because of variable estimates of risk of metastasis. We aimed to determine the prevalence and risk factors of metastasis of NAD-NETs ≤19 mm and evaluate the long-term survival of patients after ET as compared with radical surgery.

METHODS

The Surveillance Epidemiology and End Result database was used to identify 1243 patients with T1-2 histologically confirmed NAD-NETs ≤19 mm in size. Cancer-specific survival (CSS) and overall survival (OS) were calculated.

RESULTS

Overall, 4.8% of cases had metastasis at the time of diagnosis, with lower prevalence in ≤10-mm lesions (3.1%) versus 11- to 19-mm lesions (11.7%, P < .001). The risk factors for metastases included invasion to the muscularis propria (odds ratio, 25.95; 95% confidence interval, 9.01-76.70), age <65 years (odds ratio, 1.93), submucosal involvement (odds ratio, 3.1), and 11 to 19 mm in size (vs ≤10 mm). In patients with well- to moderately differentiated T1-2N0M0 NAD-NETs ≤19 mm confined to the mucosa/submucosa who underwent ET or surgery, the 5-year CSS was 100%. The 5-year OS was similar between the ≤10-mm and 11- to 19-mm groups (86.6% vs 91.0%, P = .31) and the ET and surgery groups (87.4% vs 87.5%, P = .823).

CONCLUSIONS

In NAD-NETs, invasion to the muscularis propria is the strongest risk factor for metastasis. In the absence of metastasis, in lesions with well/moderate differentiation and without muscle invasion, ET is adequate for NAD-NETs ≤10 mm and is a viable option for 11- to 19-mm lesions.

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

BACKGROUND

Periampullary neuroendocrine tumors (NETs) arise from the duodenum, ampulla, and periampullary pancreas. Duodenal and ampullary NETs are rare and may have distinct biologic behavior from pancreatic NETs (P-NETs). We examined the outcomes of these entities.

METHODS

An institutional database was queried for patients undergoing resection for pancreatic head, duodenal, or ampullary NETs from 2000 to 2018. Patients with MEN1 syndrome or follow up less than 12 months were excluded.

RESULTS

Three hundred and ten patients were identified. Tumor locations were ampulla (n = 15), duodenum (n = 35) and pancreas (n = 260). Median follow-up and recurrence-free survival (RFS) were 60.9 (interquartile range [IQR]: 34.8-99.3) and 171.7 (IQR: 84.0-NR) months. Clinicopathologic data and survival outcomes were similar for duodenal and ampullary NETs (RFS: p = .347 and overall survival [OS]: p = .246) and were combined into an intestinal subtype (IS) group. There were no differences in OS or RFS when comparing IS-NET and P-NET. On multivariate analysis, tissue of origin was not associated with risk of recurrence. The current American Joint Committee on Cancer staging guidelines, which account for origin tissue, were predictive of outcomes for all subtypes.

CONCLUSION

Tissue of origin does not appear to impact long-term outcomes when comparing IS-NETs and P-NETs. The AJCC staging system offers good discriminatory capacity in the context of the tissue type.