Ki67 is a Prognostic Marker for Neuroendocrine Tumors

Abstract

ABSTRACT Aim: To explore the expression of Ki67 in neuroendocrine tumors (NETs) and evaluate its prognostic value in patients with NETs. Methods: A retrospective 188 patients diagnosed with histopathologically confirmation NETs at the first Affiliated Hospital of Nanjing Medical University from January, 2005 to December, 2010 were received. Immunohistochemical staining for Ki67 was performed using archived tumor blocks. The expression of Ki67 in tumor specimens was used to determine the NET grade (G1, G2, or G3); tumor node metastasis (TNM) classification data were also collected for analysis. Results: Of 106 patients with TNM staging data available, the mortality rate of stage I, II, III, IV was 9.4%, 17.1%, 40%, and 64.3%; mean overall survival (mOS) was 34.2, 24.1, 24.1 and 24.0 months; the two-year survival rate was 83.9%, 85.7%, 55.2% and 33.7%; and the five-year survival rate was 83.9%, 76.2%, 55.2% and 16.8%. For G1, G2, and G3 tumor grades, the mortality rate was 10.9%, 45.0% and 54.5%; mOS was 39.3, 29.0, and 24.0 months; the 2-year survival rate was 83.3%, 46.4%, and 34.0%; and the 5-year survival rate was 77.8%, 46.4%, and 34.0%. There were significant differences among different TNM stages and Ki67 tumor grading for mOS, and 2-year and 5-year survival rates (P Conclusions: Patients with NETs of higher TNM stage or higher Ki67 proliferation index had a poorer prognosis, compared to those with NETs of a lower stage or grade. The Ki67 proliferative index is an essential parameter for predicting the prognosis of patients with NETs. Disclosure: All authors have declared no conflicts of interest.