Expression of CD44s and CD44v6 in Lung Cancer and Their Correlation with Prognostic Factors

Abstract

Background CD44, a transmembrane glycoprotein receptor, plays a major role in tumor progression and metastasis. Objective: To evaluate the expression of CD44 standard (CD44s) and its variant 6 (CD44v6) in normal and neoplastic lung tissue and correlate it with prognostic factors in lung cancer. Methods The study included 52 non-small cell lung carcinomas (NSCLC) (21 squamous cell carcinomas and 31 adenocarcinomas), 15 small cell lung carcinomas (SCLC) and 8 carcinoid tumors. Expression of CD44s and CD44v6 was evaluated by immunohistochemistry and correlated with lung cancer prognostic factors. Results All squamous cell carcinomas expressed both CD44s and CD44v6. Adenocarcinomas expressed CD44s in 39% of cases and CD44v6 in 45%. Carcinoid tumors expressed only CD44s in 88% of cases. All SCLCS were negative for both CD44s and CD44v6. A restricted panel consisting of CD44s and CD44v6 will discriminate NSCLC from SCLC with a sensitivity of 67% and a specificity of 100%. In adenocarcinoma CD44s expression was significantly correlated with lymph node metastases (p=0.007) while CD44v6 expression was more significantly associated with tumor size (p=0.0032). Conclusions CD44s and CD44v6 are expressed in certain types of lung cancer. In adenocarcinoma CD44s and CD44v6 expression is significantly correlated with lymph node metastases and tumor size.