Neuroendocrine carcinoma of the esophagus: a case report with immunohistochemical and molecular genetic analyses of KIT and PDGFRA

Avapritinib efficacy in primary hepatic neuroendocrine carcinoma with elevated PDGFRA expression: Insights from a PDX model study

BACKGROUND & AIMS

Primary Hepatic Neuroendocrine Carcinoma (PHNEC) is a rare and aggressive tumor with high recurrence rates. Surgical resection remains the only therapeutic strategy. The effectiveness of tyrosine kinase inhibitors (TKIs) for PHNEC remains unclear due to limited research.

METHODS

We employed immunohistochemical staining to diagnose PHNEC and assess the expression of eight tyrosine kinase receptors in tumor tissues, including VEGFRs, PDGFRA, EGFR, FGFRs et al. A patient-derived xenograft (PDX) model was established using PHNEC tumor tissues to test the efficacy of TKIs. PDX mice bearing tumors were treated with Avapritinib, an FDA-approved PDGFRA-targeting drug, at a daily oral dose of 10 mg/kg for 2 weeks.

RESULTS

Pathological analysis confirmed the diagnosis of PHNEC with positive expression of Neural cell adhesion molecule (NCAM/CD56), Synaptophysin (Syn), and Somatostatin receptor 2 (SSTR-2), and negative expression of Hep (Hepatocyte Paraffin 1), a biomarker for Hepatocellular carcinoma. Notably, PDGFRA was significantly overexpressed in PHNEC tumor tissues compared to other tyrosine kinases. Avapritinib treatment significantly reduced tumor growth in PDX mice by 73.9 % (p = 0.008). Additionally, Avapritinib treatment led to a marked decrease in PDGFRA and Ki-67 expression, suggesting that it inhibits tumor cell proliferation by suppressing PDGFRA.

CONCLUSION

Our findings suggest that PDGFRA is a potential therapeutic target for PHNEC, and its inhibition with Avapritinib may offer clinical benefits to patients with this rare malignancy.

High-grade large cell neuroendocrine carcinoma of the esophagus: a case report and review of the literature

BACKGROUND

Neuroendocrine carcinomas are extremely rare in the esophagus as they represent less than 0.04% of all neuroendocrine tumors. To date, only 14 cases of poorly differentiated, high-grade esophageal NEC have been described in the literature. The majority of these patients presented with typical dysphagia symptoms. Due to its rarity, no standardized guidelines have been proposed to treat esophageal neuroendocrine carcinoma, although general recommendations suggest surgery with adjuvant chemoradiotherapy as the treatment of choice.

CASE PRESENTATION

A 67-year-old previously healthy White male presented with a year-long intermittent nonspecific retrosternal discomfort, with the absence of any other symptoms. Esophagogastroduodenoscopy revealed an ulcerative mass in his lower esophagus, with concern of malignancy. Endoscopic ultrasound-guided biopsy revealed poorly differentiated neuroendocrine carcinoma of the esophagus with metastasis to a diaphragmatic lymph node. He was treated with neoadjuvant chemoradiation followed by surgery, and he has been in remission for over 5 years.

CONCLUSION

Here, we review the literature and report a unique case of a patient with a vague presentation of esophageal neuroendocrine carcinoma as he enters his sixth year of survival following neoadjuvant chemoradiotherapy.

Clinicopathological analysis of 67 cases of esophageal neuroendocrine carcinoma and the effect of postoperative adjuvant therapy on prognosis

The clinicopathological properties of esophageal neuroendocrine carcinoma (ENEC) and its optimal therapy have not been widely studied, as the disease is not common. Consequently, we conducted a retrospective study to analyze the clinical features as well as the prognosis of patients with surgically resected ENEC.The clinicopathological data of patients with ENEC who underwent esophagostomy with regional lymphadenectomy at Jiangsu Province People's Hospital and Jiangsu Provincial Tumor Hospital starting January 2008 until December 2014 were collected.Ninety-two cases of ENEC were part of this study. However, only 67 patients were analyzed and followed up. A univariate model for the Cox proportional hazards revealed that prognosis was associated with postoperative adjuvant therapy, age, and lymph node metastasis (P < .05); a multivariate Cox proportional hazards model showed that postoperative adjuvant therapy was a significant independent prognostic factor. Postoperative adjuvant therapy directly affected overall survival, with a significant disparity noted between the groups (P = .022). In this study, patients who received adjuvant therapy had an average time of survival of 39 months (interquartile range: 27.068-50.932 months), while those who did not receive adjuvant therapy had an average survival time of 13 months (interquartile range: 10.129-15.871 months). The survival time was longer in the treated group than in the untreated group (hazard ratio = 0.47; 95% confidence interval: 0.23-0.94; P = .034).ENEC is a heterogeneous tumor with a very poor prognosis. Combining surgery with adjuvant and/or chemotherapy significantly prolongs the survival of patients, and the optimal treatment for ENEC should be determined with future prospective studies.

Unraveling molecular pathways of poorly differentiated neuroendocrine carcinomas of the gastroenteropancreatic system: A systematic review

BACKGROUND

Poorly differentiated neuroendocrine carcinomas (NECs) are rare and aggressive tumors. Their molecular pathogenesis is still largely unknown, and consequently, the best therapeutic management also remains to be determined. We conducted a systematic review on molecular alterations found in gastroenteropancreatic NECs (GEP-NECs) and discuss potential applications of targeted therapies in setting.

MATERIALS AND METHODS

Systematic review of studies about molecular features in tumor tissues of patients with GEP-NECs. The Medline, Lilacs, Embase, Cochrane, Scopus and Opengrey databases were sought, without time, study design or language restrictions.

RESULTS

Of the 1.564 studies retrieved, 41 were eligible: 33 were retrospective studies and eight were case reports. The studies spanned the years 1997-2017 and involved mostly colorectal, stomach and pancreas primary tumors. Molecular alterations in the TP53 gene and the p53 protein expression were the most commonly observed, regardless of the primary site. Other consistently found molecular alterations were microsatellite instability (MSI) in approximately 10% of gastric and colorectal NEC, and altered signaling cascades of p16/Rb/cyclin D1, Hedgehog and Notch pathways, and somatic mutations in KRAS, BRAF, RB1 and Bcl2. In studies of mixed adeno-neuroendocrine carcinomas (MANECs) the molecular features of GEP-NEC largely resemble their carcinoma/adenocarcinomas tumor counterparts.

CONCLUSIONS

Despite the paucity of data about the molecular drivers associated with GEP-NEC, some alterations may be potentially targeted with new cancer-directed therapies. Collaborative clinical trials for patients with advanced GEP-NEC are urgently needed.

Human ductal plate and its derivatives express antigens of cholangiocellular, hepatocellular, hepatic stellate/progenitor cell, stem cell, and neuroendocrine lineages, and proliferative antigens

Molecular mechanisms of human ductal plate (DP) development and differentiation (DD) are unclear. The author immunohistochemically investigated expressions of cholangiocellular antigens (CEA, CA19-9, EMA, MUC1, MUC2, MUC5AC, MUC6, mucins, CK7, and CK19), hepatocellular antigens (HepPar1, AFP, CK8, and CK18), hepatic stellate/progenitor cell (HSC) antigens or stem cell (SC) antigens (C-erbB2, CD56, chromogranin, synaptophysin, bcl2, NSE, NCAM, KIT, and PDGFRA), and proliferating antigen (Ki67) in 32 human fetal livers (HFL). The DD of human intrahepatic bile duct (IBD) could be categorized into four stages: DP, remodeling DP, remodeled DP, and immature IBD. All the molecules examined were expressed in the DP and DP derivatives. These results suggest that human DP or DP derivatives have capacities to differentiate into cholangiocellular, hepatocellular, HSC, SC, and neuroendocrine lineages. The data also suggest that NCAM, KIT/SC factor-signaling, NSE, HGF/MET signaling, PDGFa/PDGFRA signaling, chromogranin, synaptophysin, and CD56 play important roles in DD of DP and biliary cells of HFL. DP, DP derivatives, and IBD in HFL have proliferative capacity.

Human fetal ductal plate revisited. I. ductal plate expresses NCAM, KIT, MET, PDGFRA, and neuroendocrine antigens (NSE, chromogranin, synaptophysin, and CD56)

BACKGROUND

The molecular mechanisms of ductal plate (DP) development and differentiation (DD) in human fetal livers (HFLs) are unclear.

MATERIALS AND METHODS

The author immunohistochemically investigated expressions of NCAM, KIT, KIT, PDGFRA, and neuroendocrine antigens in 32 HFLs.

RESULTS

The processes of human intrahepatic bile duct (IBD) DD could be categorized into four stages: DP, remodeling DP, remodeled DP, and mature IBD. NCAM was always expressed in DP and remodeling DP, but not in remodeled DP and mature IBD. The biliary elements were positive for cytokeratin (CK)7, 8, 18, and 19. The hepatoblasts were positive for CK8 and CD18, but negative for CK7 and CK19; however, periportal hepatoblasts showed biliary-type CKs (CK7 and CK19). NCAM was always expressed in DP and remodeling DP, but not in remodeled DP and mature IBD. KIT was occasionally (12/32 cases) expressed in DP and remodeling DP, but not in remodeled DP and mature IBD. NCAM expression was also seen in some hepatoblasts and hematopoietic cells and neurons. KIT was also expressed in some hepatoblasts, hematopoietic cells, and mast cells. MET and PDGFRA were strongly expressed in DP, remodeling DP, remodeled DP, and mature IBD. MET and PDGFRA were also strongly expressed in hepatoblasts and hematopoietic cells. MET and PDGFRA were not expressed in portal mesenchyme, portal veins, sinusoids, and hepatic veins. DP showed immunoreactive chromogranin, synaptophysin, neuron-specific enolase (NSE), and CD56. Expressions of chromogranin and CD56 were infrequently seen in remodeling DP. No expressions of these four neuroendocrine antigens were seen in remodeled DP and mature IBD. The nerve fibers were consistently positive for chromogranin, synaptophysin, NSE, and CD56 in the portal mesenchyme in the stages of remodeling DP, remodeled DP, and mature IBDs.

CONCLUSIONS

The data suggest that NCAM, KIT/stem cell factor-signaling, NSE, hepatocyte growth factor/MET signaling, PDGFα/PDGFRA signaling, chromogranin, synaptophysin, and CD56 play important roles in DD of biliary cells of HFL. They also suggest that the DP cells having neuroendocrine molecules give rise to hepatic stem/progenitor cells.