Objective: To evaluate the effect of resection of primary lesion and chemotherapy on survival of patients with metastatic colorectal neuroendocrine carcinoma (CRNEC).
Methods: Clinical data of 393 patients with metastatic CRNECs between January 2010 and December 2016 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database, including 171 patients who received resection of primary lesion and 221 patients who did not undergo surgery. With the propensity score matching method 172 non-operated patients were selected as controls. Kaplan-Meier method and Log-rank test were used to evaluate the survival differences, while the prognostic factors were analyzed by Cox proportional-hazards model. Metastatic CRNEC patients from January 2001 to December 2021 in Affiliated Jinhua Hospital, Zhejiang University School of Medicine were selected for validation.
Results: Compared with non-operated patients, patients who received resection had longer cause-specific survival ( P<0.05). Patients with resected positive lymph nodes>8 had a poorer prognosis compared to those with resected positive lymph nodes≤8 ( P<0.05). Multivariate analysis showed that gender, location of primary lesion and treatments were independent risk factors for cause-specific survival in patients with metastatic CRNEC (all P<0.05). For metastatic CRNEC patients with resection of primary lesion, rectal neuroendocrine carcinoma, positive resected lymph nodes≤8 and resection of primary lesion combined with chemotherapy were associated with better cause-specific survival (all P<0.05).
Conclusions: Patients with metastatic CRNEC may benefit from resection of primary lesion, and resection of primary lesion combined with chemotherapy might be the better strategy for metastatic CRNECs. The number of positive lymph nodes resected is correlated with the prognosis of patients.
Keywords: Chemotherapy; Colorectal neuroendocrine carcinoma; Prognosis; Surgery; Surveillance, Epidemiology, and End Results database.