Gastric Neuroendocrine Carcinoma Research Articles

Comparison of proximal and distal gastric neuroendocrine carcinoma based on SEER database

The occurrence of gastric neuroendocrine carcinoma (GNEC) is on the rise, and its prognosis is extremely poor. We compared survival outcomes between distal and proximal GNEC and developed a nomogram incorporating tumor site to enhance personalized management for patients with GNEC. 1807 patients were divided into DGNEC and PGNEC groups. We performed analyses by using propensity score matching (PSM) and Fine-Gray competing risk methods. A predictive nomogram for the prognosis of GNEC was constructed and validated. The cumulative incidence of cancer-specific death (CSD) in the DGNEC group was lower than that in the PGNEC group. Subgroup analysis showed lower CSD of DGNEC in males, females, tumor sizes (≤ 2 cm, 2 < tumor size ≤ 5 cm, > 5 cm, and unknown), grade stage I-II, and AJCC stage I-III, chemotherapy or no chemotherapy, surgery or no surgery groups (P < 0.05). Multivariate analysis revealed a significant association between PGNEC and CSD (HR, 1.4; 95% CI 1.13–1.73; P = 0.02). The independent predictors of CSD in patients with GNEC were primary site, gender, age, tumor size, AJCC stage, T stage, N stage, grade stage, and surgery. A predictive model based on multivariate analysis was constructed to estimate the probability of CSD at 1-, 3-, and 5-year. The calibration curves demonstrated excellent consistency between the predicted and observed probabilities of CSD. Patients with DGNEC have a better prognosis than those with PGNEC. The model exhibits strong predictive capability for these patients.

Synergizing traditional CT imaging with radiomics: a novel model for preoperative diagnosis of gastric neuroendocrine and mixed adenoneuroendocrine carcinoma.

To develop diagnostic models for differentiating gastric neuroendocrine carcinoma (g-NEC) and gastric mixed adeno-neuroendocrine carcinoma (g-MANEC) from gastric adenocarcinoma (g-ADC) based on traditional contrast enhanced CT imaging features and radiomics features. We retrospectively analyzed 90 g-(MA)NEC (g-MANEC and g-NEC) patients matched 1:1 by T-stage with 90 g-ADC patients. Traditional CT features were analyzed using univariable and multivariable logistic regression. Tumor segmentation and radiomics features extraction were performed with Slicer and PyRadiomics. Feature selection was conducted through univariable analysis, correlation analysis, LASSO, and multivariable stepwise logistic. The combined model incorporated clinical and radiomics predictors. Diagnostic performance was assessed with ROC curves and DeLong's test. The models' diagnostic efficacy was further validated in subgroup of g-NEC vs. g-ADC and g-MANEC vs. g-ADC cases. Tumor necrosis and lymph node metastasis were independent predictors for differentiating g-(MA)NEC from g-ADC (P < 0.05). The clinical model's AUC was 0.700 (training) and 0.667(validation). Five radiomics features were retained, with the radiomics model showing AUC of 0.809 (training) and 0.802 (validation). The combined model's AUCs were 0.853 (training) and 0.812 (validation), significantly outperforming the clinical model (P < 0.05). Subgroup analysis revealed that the combined model exhibited acceptable performance in differentiating g-NEC from g-ADC and g-MANEC from g-ADC, with AUCof0.887 and 0.823 in the training cohort and 0.852 and 0.762 in the validation cohort. A combined model based on traditional CT imaging and radiomic features provides a non-invasive and effective preoperative diagnostic method for differentiating g-(MA)NEC from g-ADC.

Clinical and pathological characteristics of gastric large cell neuroendocrine carcinoma: A report of 2 cases series and literature review.

Gastric large cell neuroendocrine carcinoma (LCNEC) is a rare, aggressive neuroendocrine carcinoma that arises from the stomach and with high malignancy. Patients with gastric LCNEC usually have a poor prognosis. The standard treatment plan has not been established and its curative effect is poor. The present study described 2 cases diagnosed with gastric LCNEC and reviewed in depth the literature to improve our understanding more about this uncommon tumor and further to provide more experience to diagnose and treat this disease. The present study reported 2 cases of gastric LCNEC in male patients aged 51 and 73 years old, respectively. Both patients had epigastric discomfort, pain, acid reflux and heartburn. The medical history was unremarkable. The ulcerative lesion located at gastric was examined in the 2 patients by taking the esophagogastroduodenoscopy (EGO), computed tomography (CT) and digital gastrointestinal radiography (GI), that both were suspected gastric malignancy. Endoscopic biopsies of the tumor led to the initial diagnosis of gastric cancer. Postoperative pathological and immunohistochemical examinations of the surgical specimens confirmed that 1 case had mixed adeno-neuroendocrine carcinoma (MANEC) and the other had LCNEC. Both patients underwent surgical resection and received etoposide-cisplatin combination chemotherapy following surgery. The operation was successful. Both patients had uneventful recoveries following surgery, and had been followed-up regularly. The general condition was satisfactory, and no tumor metastasis was observed at present.

Prognostic significance of tertiary lymphoid structures in gastric neuroendocrine carcinoma with association to delta-like ligand 3 and neuroendocrine expressions.

Gastric neuroendocrine carcinomas (NECs) are rare cancers with highly aggressive behavior. Although tertiary lymphoid structures (TLSs) are well-known prognostic factors in various cancers, their role in gastric NECs remain unexplored. Unique immunohistochemical subtypes of pulmonary NECs have been discovered, however, their feasibility in gastric NECs is unknown. The presence and maturation of TLSs (lymphoid aggregates, primary and secondary follicles) were assessed in 48 surgically resected gastric NECs and were compared with immunohistochemical subtypes, using a panel of ASCL1, NeuroD1, POU2F3, YAP1, and DLL3 with three neuroendocrine (NE) markers. Patients with secondary follicles had significantly better overall survival (OS) and recurrence-free survival (RFS; both, p = 0.004) than those without them. Based on the hierarchical clustering, gastric NECs were classified into all low/negative (31%), high-YAP1 (19%), high-DLL3/low-NE (29%), and high-NE (21%) expression groups. The high-DLL3/low-NE group was associated with absent TLSs (p = 0.026) and showed the worst OS (p = 0.026). Distant metastasis and a lack of secondary follicles were poor independent prognostic factors of OS and RFS. The assessment of TLSs is a feasible and potent biomarker for gastric NECs, thus enabling better prognosis and moreeffective immunotherapy. Furthermore, gastric NECs can be categorized as four immunohistochemically distinct groups, of which the high-DLL3/low-NE group has the worst OS with lack of TLSs.

Distinctive Phenotypic and Microenvironmental Characteristics of Neuroendocrine Carcinoma and Adenocarcinoma Components in Gastric Mixed Adenoneuroendocrine Carcinoma

This study aimed to conduct an in-depth examination of gene expression and microenvironmental profiles of gastric neuroendocrine carcinoma (NEC) and mixed adeno-NEC (MANEC). Tissue microarrays from 55 patients with gastric MANEC (N = 32) or NEC (N = 23) were analyzed using digital spatial profiling (GeoMx DSP, NanoString Technologies). Representative regions of interest were selected from the adenocarcinoma (ADC) portion (ADC-MANEC) and the NEC portion (NEC-MANEC) of the MANEC cores, and pure NEC (pNEC) cores. All regions of interest were separated into epithelial components and stromal components using the masking procedure in the GeoMx platform, followed by transcriptome analysis. Comparison of gene expression between ADC-MANEC and NEC-MANEC/pNEC identified several differentially expressed genes in the epithelial (including PEG10, MAP1B, STMN3, and AKT3) and stromal (FN1, COL1A1, SPARC, and BGN) components. Gene set enrichment analysis revealed that pathways related to the E2F target and G2M checkpoint were more enriched in NEC-MANEC and pNEC than in ADC-MANEC. Deconvolution analysis showed that the microenvironmental profile varied according to histologic differentiation. In ADC-MANEC, intraepithelial infiltrating immune cells were relatively more numerous, whereas fibroblasts in the stroma were more abundant in NEC-MANEC and pNEC. This study confirmed the distinct expression profile of each histologic component of MANEC according to its tumor vs stromal compartment using the DSP platform. Although each component of MANEC shares the same genetic origin, distinctive phenotypes should not be overlooked when managing patients with MANEC. This study provides a useful validation data set for future studies.

Updated results from first-in-human phase 1 dose-escalation trial of TAK-102, a GPC3-targeted armored CAR T cells, in patients with advanced solid tumors.

2543 Background: Glypican 3 (GPC3) is a member of the glypican family of heparan sulfate proteoglycans that are attached to the cell surface by a glycosylphosphatidylinositol anchor. High GPC3 expression rates are reported in numerous cancer types with a high unmet medical need, including hepatocellular carcinoma (HCC). TAK-102 is a GPC3-targeted autologous chimeric antigen receptor T cell (CAR-T) immunotherapy armored with IL-7 and CCL19. The addition of IL-7 and CCL19 to the construct was designed to support the expansion of memory subsets and persistence of CAR-T cells. We hypothesized TAK-102 would help overcome the challenges associated with an immunosuppressive tumor microenvironment that limit the activity of nonarmored CAR-T therapies in solid tumors. Methods: The first-in-human, Phase 1 dose escalation study evaluated TAK-102 in patients (pts) with GPC3-expressing solid tumors who were refractory or intolerant to standard treatments. TAK-102 was administered via a single infusion to 3 dose cohorts after lymphodepleting chemotherapy (LDC; consisting of fludarabine and cyclophosphamide): dose level (DL) 1 (starting cohort), 1x107 CAR+ cells/body; DL2, 1x108 CAR+ cells/body; DL3, 5x108 CAR+ cells/body. Objectives included evaluation of safety, dose-limiting toxicity (DLT), recommended phase 2 dose, cellular kinetic (CK) parameters, tumor markers, cytokine/chemokine and antitumor activity based on RECIST 1.1. Results: Eleven pts were enrolled and infused TAK-102 (DL1: 3 pts, DL2: 3 pts, DL3: 5 pts): 1 gastric neuroendocrine carcinoma, 2 liposarcoma, 8 HCC. Five pts achieved stable disease (SD), HCC (GPC3 H-Score: 36) . In patients achieving SD, the greatest reduction in tumor size was 26.4%. No DLTs or neurotoxicity were observed. Six pts experienced cytokine release syndrome (Grade1: 5 pts, Grade2: 1 pt); all cases were manageable. AFP was measured as a tumor marker for HCC. Among 8 pts with HCC, 4 had SD after treatment with TAK-102 and 3 showed a decrease or stabilization of AFP levels corresponding to their clinical status. CK profiles for pts were assessed by flow cytometry and qPCR-based assays. Overall, there was improvement in TAK-102 exposure (Cmax, AUC) when escalating from DL1 to DL2. There was a slight decrease in Tmax from DL2 to DL3. Homeostatic cytokine (IL-7) spiked post-LDC and showed no further increase after TAK-102 infusion across all the DLs. There was dose-dependency observed in peak CCL19, IFN-γ and IL-6 levels. Conclusions: TAK-102, an armored CAR-T, is well tolerated and has a manageable safety profile with some early signs of anti-tumor activity. For CK, TAK-102 exposure (Cmax, AUC) showed improvement from DL1 to DL2, and slight decrease in Tmax from DL2 to DL3. Dose-dependency was observed in peak CCL19, IFN-γ and IL-6 levels, which may point towards increased signal of activity from DL1 to DL3. Clinical trial information: NCT04405778 .

Complete response induced by nivolumab monotherapy in gastric neuroendocrine carcinoma: a case report.

No standard treatment has been established for gastric neuroendocrine carcinoma (G-NEC). We present the case of a patient with recurrent G-NEC who achieved a complete response (CR) with nivolumab. A woman in her 70s, with no significant medical or family history of illness, underwent an upper gastrointestinal endoscopy, which revealed a Borrmann type 2 tumor in the gastric antrum. Malignant tumor cells were not detected in the endoscopic biopsy samples; however, a malignant gastric tumor was strongly suspected. Therefore, surgical resection was performed, and the tumor was pathologically diagnosed as a G-NEC with liver metastases. Adjuvant etoposide plus carboplatin was administered for four cycles, but recurrence in the liver was observed 5months after the completion of adjuvant chemotherapy. Ramucirumab plus paclitaxel and irinotecan were introduced as second and third-line treatments. After these treatments, the mesenteric lymph node metastases expanded. Tumor mutation burden (TMB) was low (five mutations/megabase), and microsatellite instability remained stable. However, programmed death-ligand 1 Combined Positive Score (CPS) was ≥ 5 in the resected sample. Therefore, nivolumab monotherapy was introduced as a fourth-line treatment. The mesenteric lymph node metastases exhibited swelling 3weeks after the initiation of nivolumab; however, they rapidly shrank, and CR was later achieved. Treatment with nivolumab is currently ongoing for 12months. This is the first report of nivolumab monotherapy in a patient with G-NEC who showed pseudo-progression. Even in TMB-low and microsatellite stable cases, nivolumab may be a viable option for patients with G-NEC.

Gastric neuroendocrine neoplasms.

Gastric neuroendocrine neoplasms (gNENs) display peculiar site-specific features among all NENs. Their incidence and prevalence have been rising in the past few decades. gNENscomprise gastric neuroendocrine carcinomas (gNECs) and gastricneuroendocrine tumours (gNETs), the latter further classified into three types. Type I anatype II gNETs are gastrin-dependent and develop in chronic atrophic gastritis and as part of Zollinger-Ellison syndrome within a multiple endocrine neoplasia type 1 syndrome (MEN1), respectively. Type III or sporadic gNETs develop in the absence of hypergastrinaemia and in the context of a near-normal or inflamed gastric mucosa. gNECs can also develop in the context of variable atrophic, relatively normal or inflamed gastric mucosa. Each gNEN type has different clinical characteristics and requires a different multidisciplinary approach in expert dedicated centres. Type I gNETs are managed mainly by endoscopy or surgery, whereas the treatment of typeII gNETs largely depends on the management of the concomitant MEN1. Type III gNETs may require both locoregional approaches and systemic treatments; NECs are often metastatic and therefore require systemic treatment. Specific data regarding the systemic treatment of gNENs are lacking and are derived from the treatment of intestinal NETs and NECs. An enhanced understanding of molecular and clinical pathophysiology is needed to improve the management and outcomes of patients' gNETs.

Gastric Small Cell Neuroendocrine Carcinoma With Loss of Epithelial Markers Expression.

Given that gastric small cell neuroendocrine carcinoma (SCNEC) is notably more aggressive than conventional adenocarcinoma, and a platinum-based regimen aligned with the treatment for pulmonary SCNEC is advocated when chemotherapy is needed, ensuring an accurate pathological diagnosis is paramount. A 63-year-old man, examined for melena, underwent gastroscopy which revealed a total circumferential Borrmann type 3 lesion extending from the pylorus to the antrum of the stomach. He underwent a distal gastrectomy with D2 lymphadenectomy. The microscopic examination revealed SCNEC with a minor adenocarcinoma component. Immunohistochemically, the SCNEC was diffusely positive for synaptophysin, CD56, and INSM1, very focally positive for chromogranin A, and negative for leukocyte common antigen, CD3, and CD20. A significant observation in this case was the complete negativity for epithelial markers including keratin (CK7, CK8, CK20, CAM5.2, and AE1/AE3) and epithelial membrane antigen. Diffuse positivity for neuroendocrine markers, negativity for other lineage markers, and a transition from the adenocarcinoma component, if present, serve as significant diagnostic clues for gastric SCNEC with loss of epithelial markers expression. SCNEC should not be excluded solely based on the negative result for epithelial markers.

Claudin 18.2 expression in digestive neuroendocrine neoplasms: a clinicopathological study.

Claudin 18.2-targeted therapy has shown significant efficacy in treating claudin 18.2-positive cancers. However, limited systematic studies have investigated characteristics of claudin 18.2 expression in neuroendocrine neoplasms (NENs). Data and specimens from 403 cases of digestive NENs were retrospectively collected, and claudin 18.2 expression was detected using immunochemical staining. Claudin 18.2 was positive in 19.6% (79/403) of the digestive NENs. The highest positive rate of claudin 18.2 was observed in gastric NENs (72/259, 27.8%), accounting for 91.1% (72/79) of all positive cases. The positivity rate was significantly higher in gastric NENs compared to pancreatic (2/78, 2.6%) or colorectal NENs (2/38, 5.3%; p < 0.05). For digestive NENs, claudin 18.2 positivity was significantly higher in neuroendocrine carcinomas (NECs) (37/144, 25.7%) than in neuroendocrine tumours (NETs; 14/160, 8.8%; p < 0.001), but no significant difference was found between gastric NECs (59/213, 27.7%) and gastric NETs (13/46, 28.3%; p > 0.05). The positivity was significantly higher in large-cell NECs (LCNECs; 28/79, 35.4%) and MiNEN (mixed neuroendocrine-non- neuroendocrine neoplasms)-LCNECs (23/66, 34.8%) compared to small-cell NECs (SCNECs; 9/65, 13.8%) and MiNEN-SCNECs (5/33, 15.2%; p < 0.05). Claudin 18.2 expression was more prevalent in gastric NENs than in pancreatic (12.5 ×; p = 0.001) and colorectal NENs (5.9 ×; p = 0.021). Claudin 18.2 staining was a useful method for identify the gastric origins of NETs, with a sensitivity of 28.3% and a specificity of 99.1%. The expression characteristics of claudin 18.2 in NENs were characterized, which may provide a clinicopathological reference for targeted therapies in patients with NENs.

S4146 Pancreatic Incidentaloma Leading to Small Cell Gastric Neuroendocrine Carcinoma Diagnosis

S4146 Pancreatic Incidentaloma Leading to Small Cell Gastric Neuroendocrine Carcinoma Diagnosis

Equivalent Survival between Gastric Large-Cell Neuroendocrine Carcinoma and Gastric Small-Cell Neuroendocrine Carcinoma.

According to the 2019 World Health Organization (WHO) classification of gastric neuroendocrine neoplasms, gastric neuroendocrine carcinoma (GNEC) can be further divided into gastric large-cell neuroendocrine carcinoma (GLNEC) and gastric small-cell neuroendocrine carcinoma (GSNEC). Whether the prognoses of the two types have a discrepancy has long been disputed. We collected patients diagnosed with GLNEC or GSNEC in the National Cancer Center of China between January 2000 and December 2020. The characteristics and survival outcomes were compared between the two groups. We further verified our conclusion using the SEER dataset. A total of 114 GNEC patients, including 82 patients with GLNEC and 32 patients with GSNEC, have completed treatment in our hospital. Clinicopathologic differences were not observed between patients with GSNEC and GLNEC concerning the sex, age, body mass index, Charlson Comorbidity Index, tumor location, tumor size, stage, treatment received, the expression of neuroendocrine markers (CD56, Chromogranin A, synaptophysin), and score on the Ki-67 index. The 1-year, 3-year, and 5-year overall survival rates of GLNEC and GSNEC were 89.0%, 60.5%, and 52.4%, and 93.8%, 56.3%, and 52.7%, which showed no statistically significant differences. This result was confirmed further by using the SEER dataset after the inverse probability of treatment weighting. Although with different cell morphology, the comparison of prognosis between the GLNEC and GSNEC has no significant statistical difference.

Evaluation of the safety and immunological effects of Bacillus Calmette–Guérin in combination with checkpoint inhibitor therapy in a patient with neuroendocrine carcinoma: a case report

BackgroundImmune checkpoint inhibitors have revolutionized therapy of advanced and metastatic cancers. However, a significant proportion of patients do not respond to immune checkpoint inhibitors or develop resistance. Therefore, novel therapies or combinations of therapies that may act synergistically are needed. It has been suggested that induction of trained immunity may increase the response to immune checkpoint inhibitor therapy, through reprogramming myeloid cells toward an antitumor phenotype. On the other hand, activation of the immune system also carries the risk of potentially sustaining tumorgenicity and increasing immune- related toxicity.Case presentationWe report the case of a 37-year-old Dutch male suffering from gastric neuroendocrine carcinoma with liver metastases and high risk for an unfavorable outcome, who was treated with a combination of programmed cell death protein 1 inhibitor nivolumab and the trained immunity-inducer Bacillus Calmette–Guérin vaccine as a salvage therapy. Three doses of BCG vaccine were administered at 3-month intervals, in conjunction with the immune checkpoint inhibitor regimen. At a certain point, radiation therapy was added to the treatment regimen. During the combination of these therapies, the patient developed immune-mediated colitis, which necessitated discontinuation of all treatments. Bacillus Calmette–Guérin vaccination induced a trained immune response with elevated monocyte-derived interleukin-6 and interleukin-1β production capacity. From the first vaccination with Bacillus Calmette–Guérin until 3 months after the last vaccination with Bacillus Calmette–Guérin, the patient displayed only mild progression of the primary tumor and no progression of the metastases.ConclusionIn this study, we show the feasibility to combine checkpoint inhibitor therapy with inducers of trained immunity in a patient with an aggressive neuroendocrine tumor. Autoimmune side effects are common under programmed cell death protein 1 inhibitor therapy, which was considered the most likely cause of colitis, although an additive effect of Bacillus Calmette–Guérin vaccination or radiotherapy cannot be excluded. The patient displayed only mild progression during the combination therapy, but larger studies are warranted to fully explore the potential benefit of trained immunity inducers as an adjuvant to immune checkpoint inhibitor therapy.

Endoscopic features of gastric neuroendocrine carcinoma.

The endoscopic features of gastric neuroendocrine carcinoma (G-NEC) have not been clarified; therefore, they were investigated in relation to clinicopathological findings. Consecutive patients with G-NECs who had undergone endoscopic or surgical resection at our institution between January 2005 and March 2022 were included in this retrospective study. The endoscopic and clinicopathological findings of the lesions were analyzed to provide information of diagnostic value. In addition, cases of gastric neuroendocrine tumor (G-NET) and common-type gastric adenocarcinoma treated in the same study period were identified to compare the endoscopic findings between each G-NEC versus G-NET, and G-NEC versus common-type gastric adenocarcinoma. Patients with common-type gastric adenocarcinoma were matched for age, sex, tumor size, and depth of tumor invasion in 1:3 ratio. Among 15 patients with 15 G-NECs, submucosal tumor-like marginal elevation (87%), adherent white coat (67%), and ulceration with a distinct border (60%) were characteristic endoscopic findings in white-light images. Magnifying narrow-band imaging endoscopy revealed an absent microsurface (MS) pattern plus disrupted irregular microvessel (MV) in five (71%) of seven cases with evaluable MS and MV patterns. The area with an absent MS pattern plus disrupted irregular MV corresponded to the histological finding of NEC component in all five cases. These endoscopic features were all significantly more frequent in G-NECs than G-NETs (n=22) or common-type gastric adenocarcinomas (n=45). These endoscopic features should be taken into consideration to increase the index of suspicion and to improve the accuracy of target biopsies for G-NEC.

Value of a preoperative prognostic nutritional index for the prognostic evaluation of gastric neuroendocrine carcinoma patients.

To study the value of Onodera's prognostic nutrition index (PNI) in patients with gastric neuroendocrine cancer (G-NEC). The clinical data on 148 cases of G-NEC presented between March 2010 and April 2022 were retrospectively analyzed. The relationship between the clinical characteristics of the patients and PNI was analyzed. Optimal PNI cutoff values for G-NEC prognosis prediction were calculated using the X-tile software. The survival curves were created using the Kaplan-Meier method. A Cox proportional hazards model was also established to identify independent prognostic factors that impact the prognosis of patients with G-NEC. The median overall survival (OS) rate was 30 months (range 6-127 months), and the OS rates at 1, 3 and 5 years were 89.2, 71.6 and 68.2%, respectively. The mean PNI of the 148 patients before the operation was 49.5 ± 8.0. The mean PNI of patients with anemia (p < 0.001) and abnormal carcinoembryonic antigen (p = 0.039) was significantly lower than that of patients without such comorbidities. The mean PNI of patients with Stage III tumors (p < 0.001) and postoperative complications was significantly lower (p = 0.005). PNI optimal cutoff values were 50 (p < 0.001). Based on the cut-off value of the PNI, these patients were divided into a PNI-high group (PNI ≥ 50.0, n = 77) and a PNI-low group (PNI < 50.0, n = 71). The PNI-high group had a significantly better 5-years OS rate compared with the PNI-low group (76.6% vs. 59.2%, χ2 = 14.7, p < 0. 001). Multivariate analysis demonstrated that PNI and pathological stage were independent prognostic factors for patients with G-NEC. In the subgroup analysis, OS rates were significantly lower in the PNI-low group than in the PNI-high group among patients with stage I and stage III of the disease. The PNI is a simple and useful marker for predicting long-term outcomes in G-NEC patients regardless of tumor stage. Based on our results, we suggest that PNI should be included in routine assessments of patients with G-NEC.

Survival Trends and Profiling of Gastric Mixed Adenoneuroendocrine Carcinoma (gMANEC) in the Current Era

Background: Gastric mixed adenoneuroendocrine carcinoma (gMANEC) is a histopathologic diagnosis with at least 30% each of exocrine and endocrine components. Although prognosis is thought to be driven by the relative exocrine or endocrine dominance, gMANEC has been clinically treated as gastric adenocarcinoma (gAC). The overall survival of gMANEC as compared to gastric neuroendocrine carcinoma (gNEC) or gAC remains undefined. Methods: Using the National Cancer Database, patients with gastric tumors were queried from 2004 to 2016 for gMANEC, gNEC, and gAC histologies. Demographic and clinicopathologic features were recorded. Univariate and multivariate Cox proportional hazards analyses were performed to delineate factors associated with overall survival (OS). Results: Overall, 404 patients diagnosed with gMANEC were identified. Patients had a median age 68 years, were majority male, and predominantly Caucasian. Gastric MANEC was more frequently poorly differentiated (73%vs 52% (gAC) vs 20% (gNEC), P &lt; .001) with lymphovascular invasion (57%vs 38%vs 27%, P &lt; .001) and lymph node involvement (59%vs 49%vs 36%, P &lt; .001); these factors were associated with worse OS on univariable analysis. Finally, tumors &gt;5 cm and lymph node involvement were independent predictors of worse survival. The median OS of patients with gMANEC was 41.5 months. Conclusion: Gastric MANEC and gAC have a similarly dismal prognosis and thus should be continued to treat like gAC. Pathologic nodal metastasis, tumor size and grade are useful prognostic factors.

A novel nomogram and risk stratification system predicting the cancer-specific survival of patients with gastric neuroendocrine carcinoma: a study based on SEER database and external validation

BackgroundGastric neuroendocrine carcinoma (GNEC) is a rare histology of gastric cancer. The retrospective study was designed to construct and validate a nomogram for predicting the cancer-specific survival (CSS) of postoperative GNEC patients.MethodsData for 28 patients from the Hangzhou TCM Hospital were identified as the external validation cohort. A total of 1493 patients were included in the SEER database and randomly assigned to the training group (1045 patients) and internal validation group (448 patients). The nomogram was constructed using the findings of univariate and multivariate Cox regression studies. The model was evaluated by consistency index (C-index), calibration plots, and clinical net benefit. Finally, the effect between the nomogram and AJCC staging system was compared by net reclassification index (NRI) and integrated discrimination improvement (IDI).ResultsAge, gender, grade, T stage, N stage, metastasis, primary site, tumor size, RNE, and chemotherapy were incorporated in the nomogram. The C-indexes were 0.792 and 0.782 in the training and internal verification sets. The 1-, 3-, and 5-year CSS predicted by the nomogram and actual measurements had good agreement in calibration plots. The 1-, 3-, and 5-year NRI were 0.21, 0.29, and 0.37, respectively. The 1-, 3-, and 5-year IDI values were 0.10, 0.12, and 0.13 (P < 0.001), respectively. In 1-, 3-, and 5-year CSS prediction using DCA curves, the nomogram outperformed the AJCC staging system. The nomogram performed well in both the internal and external validation cohorts.ConclusionWe developed and validated a nomogram to predict 1-, 3-, and 5-year CSS for GNEC patients after surgical resection. This well-performing model could help doctors enhance the treatment plan.

Molecular profiling of gastric neuroendocrine carcinomas

Gastric neuroendocrine carcinoma (G-NEC) usually has NEC and adenocarcinoma components and is considered to have a common origin in gastric adenocarcinoma because common pathogenic mutations are shared. However, G-NEC without adenocarcinoma also exists, and it may have a different mechanism of tumorigenesis. We aimed to elucidate the tumorigenesis of G-NEC by focusing on the proportion of NEC components. Thirteen patients with G-NEC were included in this study. Comprehensive genetic analysis using whole-exome sequencing was performed. G-NEC without an adenocarcinoma component was defined as pure NEC. TP53 was detected as the most frequent gene mutation (85% of the patients), independent of classification. RB1, KMT2C, LTBP1, and RYR2 mutations were identified in two of three pure NEC patients but were not detected in other G-NEC patients. Pure NEC has different somatic mutation profile than other NECs. This study provides insights into the mechanism of tumorigenesis in G-NEC.

Neuroendocrine carcinoma of the small intestine diagnosed as a result of paraneoplastic neurological syndrome.

Paraneoplastic neurological syndromes, a diverse group of neurological syndromes, are associated with small cell lung, testicular, ovarian, and breast cancers; however, their association with neuroendocrine carcinoma of the small intestine remains unreported. In this report, we present the case of a 78-year-old man diagnosed with neuroendocrine carcinoma of the small intestine and experienced symptoms such as subacute progressive numbness of the extremities and impaired gait. These symptoms were diagnosed as tumor-associated neurological syndrome. The patient had also undergone pyloric gastrectomy for early-stage gastric cancer several years prior to the appearance of the neurological symptoms. Therefore, we could not determine whether the tumor-related neurologic syndrome was owing to gastric cancer or neuroendocrine carcinoma of the small intestine; however, one of these conditions was the cause of the neuropathy. The gait disturbance and numbness relatively improved after surgery for the neuroendocrine carcinoma of the small intestine, suggesting that the neuroendocrine carcinoma of the small intestine likely caused the paraneoplastic neurological syndrome. Collectively, we present a unique report highlighting the putative relationship between small bowel neuroendocrine carcinoma and tumor-associated neurologic syndromes.

Clinicopathological and genetic characteristics of gastric neuroendocrine tumour (NET) G3 and comparisons with neuroendocrine carcinoma and NET G2.

To characterise the clinicopathological and genetic characteristics of gastric neuroendocrine tumour G3 (gNET G3) and to compare them with those of gastric neuroendocrine carcinoma (gNEC) and gNET G2. A total of 115 gastric neuroendocrine neoplasms (NENs) were included, of which gNET G3 was different from gNET G1/G2 in terms of tumour location (P = 0.029), number (P = 0.003), size (P = 0.010), the Ki67 index (P < 0.001), lymph node metastasis (P < 0.001) and TNM stage (P = 0.011), and different from gNEC/gastric mixed neuroendocrine-non-neuroendocrine neoplasm (gMiNEN) in terms of tumour size (P = 0.010) and the Ki67 index (P = 0.001). High-resolution copy number (CN) profiling and validation experiments showed CN gains and high expression of DLL3 in gNET G3. Hierarchical clustering analysis based on CN characteristics showed that gNET G3 was separated from gNEC but mixed with gNET G2. In gene set enrichment analysis, eight pathways were significantly enriched in gNEC when comparing gNET G3 and gNEC (P < 0.05), while no pathways were enriched when comparing gNET G3 and gNET G2. Whole-exome sequencing and validation experiments showed nonsense mutation of TP53 in one gNET G3, with wild-type staining for p53. In gNEC, TP53 mutations were detected in four of eight cases, and abnormal expression of p53 was detected in all cases. Gastric NET G3 is a distinct entity with unique genetic characteristics, which are different from those of gNEC than gNET G2. Our results provide insight into some molecular alterations that may contribute to the development and progression of gNET G3 and serve as potential therapeutic targets.