Promising Utility of P21-Activated Kinase 4 Expression in the Prediction of Recurrence in Patients with Early-stage Non-small Cell Lung Cancer

Background: P21-activated kinase 4 (PAK4), a significant effector of the Rho GTPases, controls various cellular processes and plays a crucial role in cancer progression and metastasis. In the current study, we sought to investigate the potential role of PAK4 as a predictive marker of recurrence in early-stage non-small cell lung cancer (NSCLC). Methods: We analyzed relative PAK4 mRNA expression levels in tumor tissue collected from 60 patients with Stage I-II NSCLC who underwent surgical resection, using quantitative reverse transcription polymerase chain reaction. Tumor, node, and metastasis staging was then determined for all tumor samples. Follow-up of patients was conducted for the next 3 years after surgery to detect recurrence. We divided patients into two groups: high- and low-expression groups according to PAK4 mRNA expression levels. Results: High expression of PAK4 was significantly associated with increased tumor stage and poor tumor differentiation in patients with early-stage NSCLC. Moreover, there was a significant association between PAK4 overexpression and high recurrence rate at 3-year follow-up ( P < 0.001). According to Kaplan–Meier survival analysis, a significant difference was observed for recurrence-free survival between high- and low-expression groups ( P < 0.001). PAK4 overexpression had a significantly shorter free recurrence survival period. Conclusion: High expression of PAK4 was significantly associated with higher rate of recurrence in patients with early-stage NSCLC. Therefore, PAK4 could be used as a predictor of recurrence after surgery in these patients.