Impact of tumor grade on pancreatic neuroendocrine tumors

Abstract

Pancreatic neuroendocrine tumors (P-NETs) are highly heterogeneous with wide spectrum of biological behaviors and growth patterns. Here, we aimed to assess the impact of tumor grading on P-NETs prognosis and survival outcomes. Patients with P-NET were recruited to determine correlations between grades and clinicopathological factors, survival outcomes and prognostic factors. A total of 152 patients with P-NETs were enrolled. G1 P-NET were associated with significantly lower rates of perineural invasion, lymphovascular invasion, lymph node involvement and distant metastasis. The pancreatic head was the most common location of P-NETs. The 1-year, 5-year and 10-year overall survival rates of the patients were 94.4%, 89.1% and 78.8%, respectively. Majority of pancreatic neuroendocrine carcinoma (P-NEC) were unresectable (90.9%), and P-NECs patients had poor survival rates (1-year, 20% and no 5-year). Male sex, tumor size ≥2.5cm, perineural invasion, lymph node invasion, metastasis, and advanced stage were significantly associated with poorer survival outcomes. Tumor grade and sex were independent survival predictors. Moreover, tumor grade was the most powerful prognostic factor. Tumor grade, sex, perineural invasion, tumor size, lymph node involvement, metastasis, and stage are survival predictors for patients with P-NETs. Tumor grade is the most powerful independent prognostic factor.