Primary tumor resection enhances the survival of pancreatic neuroendocrine carcinoma patients with liver metastasis under the definition of 2019 WHO classification

Abstract

Background: With the update and release of the newest version of WHO classification (2019) for neuroendocrine neoplasm, the clinical features, risk factors of prognosis and the effect of surgical treatment on newly classified pancreatic neuroendocrine carcinoma (pNEC) patients with liver metastasis were not deeply analyzed. In the present study, we tried to reveal the clinical features, and prognostic factors of pNEC patients with liver metastasis with the newest definition of WHO 2019, and explore whether primary tumor resection (PTR), chemotherapy and radiotherapy affect overall survival (OS) and cancer-specific survival (CSS) in those patients.

Methods: We collected data from pNEC patients with liver metastasis from the Surveillance, Epidemiology, and End Results (SEER) database who were diagnosed between 2010 and 2019. We strictly selected pNEC patients according to the 2019 WHO classification criteria. The univariate and multivariate Cox regression analysis were used to determine independent predictors of the survival of these patients. The forest plots map was drawn by R-4.2.2 software to display the results of the multivariate analysis visually. Kaplan-Meier method was used to estimate the OS and CSS. Based on the multivariate analysis outcomes, we established the predictable nomogram model to predict the prognosis of pNEC patients with liver metastasis. The calibration plots were shown to prove the predictive value of the nomogram predictable model.

Results: We identified 205 eligible pNEC patients with liver metastasis. According to the multivariable Cox regression analysis in this study, we found that PTR, chemotherapy, primary tumor size and diagnosis to treatment time were independent prognostic factors for both OS and CSS. Kaplan-Meier survival curves demonstrated that PTR and chemotherapy were correlated with increased survival for pNEC patients with liver metastasis. The accuracy of the nomogram model was visually proved by the calibration plot with acceptable predictive performance.

Conclusion: Four independent predictors of prognosis in pNEC patients with liver metastasis were identified in this study, including PTR, chemotherapy, tumor size and diagnosis to treatment time. PTR and chemotherapy for pNEC with liver metastasis could lead to a better prognosis, which may provide inspiration for practical clinical guidelines.

Keywords: Liver metastasis; Pancreatic neuroendocrine carcinoma; Primary tumor resection; SEER program; WHO classification.