Expression of Ki-67 in early glottic carcinoma and its relation to oncological outcomes following CO2 laser microsurgery.

Abstract

Introduction: The behavior of the laryngeal squamous cell carcinoma (LSCC) is marked by the degree of cell proliferation and differentiation. Ki-67 is regarded as a promising proliferation marker and has been correlated as a prognostic indicator.

Aim: The aim of the present study is to determine the Ki-67 expression and its prognostic value in LSCC.

Materials and methods: A total of eighty patients with early glottic carcinoma stage (Tis, T₁, T₂) N₀ M₀ were included. After preoperative workup, surgery was performed using LUMINES 40C CO₂ laser and tumor resection was done which was sent for histopathological diagnosis and immunohistochemistry (IHC). IHC for Ki-67 expression could be done only on 65 specimens.

Results: All patients had microscopically confirmed squamous cell carcinoma. Forty-eight out of 65 specimens (75%) stained positive for Ki-67 and 17 (25%) stained negative. Out of total 48, 29 stained 2+, 11 stained 3+ and 8 stained 4+. No difference was found in Ki-67 expression in relation to age, sex, T stage, and histological grading. The association of Ki-67 with recurrence was found to be statistically significant. The association of Ki-67 with survival was also studied and Ki-67 positivity is associated with increased mortality rate, although it was not statistically significant.

Conclusion: The proliferative index as measured by immunohistochemical staining of Ki-67 correlates with the tumor aggressiveness. High Ki-67 index is associated with early relapse and poor survival outcomes.