Prognostic and metastasis-related factors in colorectal neuroendocrine tumors: A cross-sectional study based on the Surveillance, Epidemiology and End Results

The incidence of colorectal neuroendocrine tumors (NETs) is gradually increasing with the increasing availability of colonoscopy and computed tomography. However, prognostic and metastatic factors for colorectal NETs are unknown. The aim of the present study was to identify clinicopathological prognostic and metastasis-related risk factors for colorectal NETs. Based on the Surveillance, Epidemiology and End Results (SEER) program, the data of 3,093 patients with colorectal NETs were included in the present study. χ² test, crosstabulation, Kaplan-Meier method, Cox proportional hazard regression model, nomogram and logistic regression analysis were used to evaluate the risk factors. Systemic analysis of data from 3,093 patients revealed that age (P<0.001), marital status (P<0.001), number of malignant tumors (P<0.001), histopathological grade (P<0.001) and clinical stage (P<0.001) were independent prognostic factors of cancer-specific survival (CSS). Among them, married patients exhibited longer CSS compared with unmarried patients (P<0.05). A nomogram based on these five factors with an area under the curve of 0.921 [95% confidence interval (CI), 0.908–0.934; P<0.001] was constructed. Age (P=0.010), primary tumor site (P<0.001), surgery (P<0.001), tumor size (P<0.001) and histopathological grade (P<0.001) were risk factors for distant metastasis of colorectal NETs. In conclusion, age, marital status, number of malignant tumors, histopathological grade and clinical stage may be independent prognostic factors for CSS of colorectal NETs, and the nomogram may have higher predictive efficiency compared with clinical stage. Age, primary tumor site, surgery, tumor size and histopathological grade may be risk factors for the distant metastasis of colorectal NETs.