Neuroendocrine neoplasm of the gallbladder: Clinical features, surgical efficacy, and prognosis

Clinicopathologic and molecular characteristics of neuroendocrine carcinomas of the gallbladder

Gallbladder neuroendocrine carcinomas (GB-NECs) are a rare subtype of malignant gallbladder cancer (GBC). The genetic and molecular characteristics of GB-NECs are rarely reported. This study aims to assess the frequency of microsatellite instability (MSI) in GB-NECs and characterize their clinicopathologic and molecular features in comparison with gallbladder adenocarcinomas (GB-ADCs). Data from six patients with primary GB-NECs and 13 with GB-ADCs were collected and reevaluated. MSI assay, immunohistochemistry for mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2), comprehensive genomic profiling (CGP) via next-generation sequencing (NGS), and evaluation of tumor mutation burden (TMB) were conducted on these samples. The six GB-NEC cases were all female, with a mean age of 62.0±9.2 years. Of these, two cases were diagnosed as large cell neuroendocrine carcinomas (LCNECs), while the remaining four were small cell neuroendocrine carcinomas (SCNECs). Microsatellite states observed in both GB-NECs and GB-ADCs were consistently microsatellite stable (MSS). Notably, TP53 (100%, 6/6) and RB1 (100%, 6/6) exhibited the highest mutation frequency in GB-NECs, followed by SMAD4 (50%, 3/6), GNAS (50%, 3/6), and RICTOR (33%, 2/6), with RB1, GNAS, and RICTOR specifically present in GB-NECs. Immunohistochemical (IHC) assays of p53 and Rb in the six GB-NECs were highly consistent with genetic mutations detected by targeted NGS. Moreover, no statistical difference was observed in TMB between GB-NECs and GB-ADCs (p=0.864). Although overall survival in GB-NEC patients tended to be worse than in GB-ADC patients, this difference did not reach statistical significance (p=0.119). This study has identified the microsatellite states and molecular mutation features of GB-NECs, suggesting that co-mutations in TP53 and RB1 may signify a neuroendocrine inclination in GB-NECs. The IHC assay provides an effective complement to targeted NGS for determining the functional status of p53 and Rb in clinical practice.

Demographic and temporal variations in gallbladder adenocarcinoma and neuroendocrine carcinoma: insights from a retrospective analysis of the national cancer database

INTRODUCTION

Gallbladder adenocarcinoma is the most common histologic subtype of gallbladder malignancies. In contrast, gallbladder neuroendocrine carcinomas are rare and poorly studied. This study aims to identify the demographic variables that may be associated with each histologic subtype.

METHODS

A retrospective analysis was conducted on 53,447 patients diagnosed with gallbladder neoplasms using data from the National Cancer Database (NCDB) between 2011 and 2020. Associations between demographic variables and the incidence of gallbladder adenocarcinoma and neuroendocrine carcinoma were compared using chi-square tests and post hoc analyses.

RESULTS

A total of 51,694 (96.7%) patients had adenocarcinoma, and 1753 (3.3%) had neuroendocrine histologic subtypes. The comparative analysis revealed significant associations with age, gender, and race (p < 0.05). Neuroendocrine carcinoma patients were diagnosed at a younger age compared to those with adenocarcinoma (z = 14.7). Moreover, patients with privately managed insurance had a higher likelihood of neuroendocrine carcinoma (z = 5.7), while those with Medicare were less likely (z = - 4.7). Gender differences were also notable; males were more predisposed to neuroendocrine carcinoma (z = 4.4, OR = 1.3), while females were less so (z = - 3.1). A significant increase in neuroendocrine cases was observed after 2016 (z = 2.4), while the incidence of adenocarcinoma subtypes was stable. Notable racial disparities in the diagnosis of gallbladder cancer were identified with black patients more likely to have neuroendocrine carcinoma.

CONCLUSION

This study highlights the differences in demographic and clinical characteristics of patients diagnosed with gallbladder neuroendocrine carcinomas compared to adenocarcinoma tumors. These findings highlight potential opportunities for targeted screening programs to enhance early detection efforts.

Primary gallbladder neuroendocrine neoplasm: A case report of grade 1 well-differentiated neuroendocrine tumor

INTRODUCTION

Neuroendocrine neoplasm (NENs) make up approximately 2-3 % of gallbladder malignancies, while only 0.5 % of all NENs develop in the gallbladder. Most Gallbladder neuroendocrine neoplasms (GB-NENs) are discovered incidentally during pathological examinations post-cholecystectomy.

CASE PRESENTATION

70-year-old male presents with an incidentally discovered 2.2 cm enhancing intraluminal soft tissue mass on abdominal CT scan. The mass demonstrates restricted diffusion on MR imaging, concerning for gallbladder malignancy. Radical cholecystectomy, confirms primary gallbladder neuroendocrine tumor (GB-NET). No adjuvant therapy was recommended at multidisciplinary cancer conference review. The patient is currently disease free at 18 months follow up.

DISCUSSION

The management of GB-NEN remains challenging, due to the lack of specific clinical manifestations and typical imaging features preoperatively. GB-NENs are usually asymptomatic, and the paucity of reported imaging characteristics makes prospective diagnosis of GB-NENs challenging. GB-NEN tend to be larger in size, demonstrating well defined, intact mucosa, with a thick rim of hyperintensity on diffusion weighted images (DWI). Distinguishing between gallbladder neuroendocrine carcinoma (GB-NEC) and gallbladder neuroendocrine tumor (GB-NET) on pathologic evaluation is essential in developing a treatment plan. GB-NETs have superior survival compared to GB-NECs. GB-NETs can be managed utilizing a cholecystectomy with portal lymphadenectomy +/- segment 4b/5 liver resection.

CONCLUSION

GB-NETs may achieve curative resection, if identified at an early disease stage.

Gallbladder Neuroendocrine Neoplasms in Dogs and Humans

Gallbladder neuroendocrine neoplasms (GB NENs) are among the rarest cancers reported in humans and dogs. This review provides a detailed review of the canine GB NEN literature and an interspecies comparison of demographics, clinical pathophysiology, pathobiology, and therapeutic response of GB NENs. The aim of this work is to explore the relevance of dogs as a spontaneous model for human GB NENs.

Neuroendocrine neoplasms of the gallbladder: A single institute analysis of outcomes and prognostic factors

INTRODUCTION

Neuroendocrine neoplasms (NENs) are classified as neuroendocrine tumors (NETs), neuroendocrine carcinomas (NECs), and mixed neuroendocrine and nonneuroendocrine neoplasms (MiNENs) according to World Health Organization classification. We present our experience of NENs of the gallbladder (GB) from a high-volume cancer hospital.

MATERIALS AND METHODS

The present study is a retrospective analysis of all patients with GB NENs who presented between January 2015 and June 2023. The patient details and treatment received with follow-up were noted. The primary endpoint was overall survival (OS).

RESULTS

A total of 147 patients were included in the study. The median age was 52 (27-81) years. There was a female predominance (70.7%). NEC was the most common subtype (84.4%) followed by MiNEN (12.9%) and NET (2.7%). The most common stage at presentation was metastatic (70.7%) followed by locally advanced (21.8%), and early disease (7.5%). The median follow-up was 9.92 (1.77-76.06) months. Median OS was 6.14 (3.93-8.35) months. Median OS in patients who received multimodality treatment was 20.20 (17.99-22.41) months versus 4.00 (2.91-5.10) months in those who did not receive it.

CONCLUSION

GB NENs are rare, but aggressive tumors with NEC being the most common type. Multimodality treatment yields favorable outcomes. However, the development of better systemic therapy is needed to help improve survival further.

Comparative prognosis and risk assessment in gallbladder neuroendocrine neoplasms versus adenocarcinomas

Background

Gallbladder neuroendocrine neoplasms (GB-NENs) are a rare malignant disease, with most cases diagnosed at advanced stages, often resulting in poor prognosis. However, studies regarding the prognosis of this condition and its comparison with gallbladder adenocarcinomas (GB-ADCs) have yet to yield convincing conclusions.

Methods

We extracted cases of GB-NENs and GB-ADCs from the Surveillance, Epidemiology, and End Results (SEER) database in the United States. Firstly, we corrected differences in clinical characteristics between the two groups using propensity score matching (PSM). Subsequently, we visualized and compared the survival outcomes of the two groups using the Kaplan-Meier method. Next, we employed the least absolute shrinkage and selection operator (LASSO) regression and Cox regression to identify prognostic factors for GB-NENs and constructed two nomograms for predicting prognosis. These nomograms were validated with an internal validation dataset from the SEER database and an external validation dataset from a hospital. Finally, we categorized patients into high-risk and low-risk groups based on their overall survival (OS) scores.

Results

A total of 7,105 patients were enrolled in the study, comprising 287 GB-NENs patients and, 6,818 GB-ADCs patients. There were substantial differences in clinical characteristics between patients, and GB-NENs exhibited a significantly better prognosis. Even after balancing these differences using PSM, the superior prognosis of GB-NENs remained evident. Independent prognostic factors selected through LASSO and Cox regression were age, histology type, first primary malignancy, tumor size, and surgery. Two nomograms for prognosis were developed based on these factors, and their performance was verified from three perspectives: discrimination, calibration, and clinical applicability using training, internal validation, and external validation datasets, all of which exhibited excellent validation results. Using a cutoff value of 166.5 for the OS nomogram score, patient mortality risk can be identified effectively.

Conclusion

Patients with GB-NENs have a better overall prognosis compared to those with GB-ADCs. Nomograms for GB-NENs prognosis have been effectively established and validated, making them a valuable tool for assessing the risk of mortality in clinical practice.