The Association between Tumor Cox-2 Expression and Clinico-pathological Characteristics and Treatment Outcome in Patients with Squamous Cell Carcinoma of the Larynx (LSCC)

Background: Cyclooxygenase (Cox-2) enzyme catalyses the formation of prostaglandins, which can affect cell proliferation and alter the response of the immune system to malignant cells. Squamous cell carcinoma (SCC) of larynx is widely prevalent in India and is one of the leading cancers in males. Cox-2 expression can be used as a prognostic and predictive marker in laryngeal SCC.

Aim: The primary objective of the present study was to determine the association between tumor Cox-2 expression and clinico-pathological characteristics and treatment outcome in patients with LSCC. Secondly, to evaluate the clinical utility of Cox-2 expression as a tool, to decide treatment strategy for LSCC.

Methods: A total of 72 surgically treated patients of laryngeal carcinoma enrolled in this study over a time period of 5 years. Tumor Cox-2 expression was analysed by immunohistochemistry using standard Streptavidin biotin method.

Results: Thirty seven patients had pathological node involvement, ipsilateral in 35 and bilateral in two. Cox-2 was intensely expressed in patients with advanced (N2/N3) nodal disease and perineural invasion. There was no significant difference in 5 year disease free survival and overall survival when Cox-2 was correlated with perineural invasion, extra capsular spread and the T and N stage of the disease. The potential of Cox-2 as a prognostic factor and as a target for therapeutic intervention was evaluated in many studies on head and neck cancers. But studies specifically in advanced laryngeal cancers are infrequent. In this study, out of the 35 cases of intense expression of Cox-2, 22 (62.9%) were in T4 stage, showing an increasing trend of its expression as the primary stage advances.

Conclusions: Preoperative Cox-2 analysis can be used to individualize need for routine neck dissection in cases of locally advanced laryngeal carcinoma.