Gallbladder neuroendocrine carcinoma diagnosis, treatment and prognosis based on the SEER database: A literature review

BACKGROUND: Gallbladder neuroendocrine carcinoma (GB-NEC) has a low incidence rate; therefore, its clinical characteristics, diagnosis, treatment and prognosis are not well explored. AIM: To review recent research and analyze corresponding data in the Surveillance Epidemiology and End Results (SEER) database. METHODS: Data of GB-NEC (n = 287) and gallbladder adenocarcinoma (GB-ADC) (n = 19 484) patients from 1975 to 2016 were extracted from the SEER database. Survival analysis was performed using Kaplan–Meier and Cox proportional hazards regression. P < 0.05 was considered statistically significant. We also reviewed 108 studies retrieved from PubMed and Reference Citation Analysis (https://www.referencecitationanalysis.com/). The keywords used for the search were: "(Carcinoma, Neuroendocrine) AND (Gallbladder Neoplasms)". RESULTS: The GB-NEC incidence rate was 1.6% (of all gallbladder carcinomas), male to female ratio was 1:2 and the median survival time was 7 mo. The 1-, 2-, 3- and 5-year overall survival (OS) was 36.6%, 17.8%, 13.2% and 7.3% respectively. Serum chromogranin A levels may be a specific tumor marker for the diagnosis of GB-NEC. Elevated carcinoembryonic antigen, carbohydrate antigen (CA)-19-9 and CA-125 levels were associated with poor prognosis. Age [hazard ratio (HR) = 1.027, 95% confidence interval (CI): 1.006–1.047, P = 0.01] and liver metastasis (HR = 3.055, 95% CI: 1.839–5.075, P < 0.001) are independent prognostic risk factors for OS. Patients with advanced GB-NEC treated with surgical resection combined with radiotherapy and/or chemotherapy may have a better prognosis than those treated with surgical resection alone. There was no significant difference in OS between GB-NEC and GB-ADC. CONCLUSION: The clinical manifestations and prognosis of GB-NEC are similar to GB-ADC, but the treatment is completely different. Early diagnosis and treatment are the top priorities.