Prognostic role of multidrug resistance-associated protein 1 expression and platelet count in operable non-small cell lung cancer.

The overall survival rate of patients with non-small cell lung cancer (NSCLC) following resection remains poor due to the high rates of recurrence and metastasis. The investigation of novel biomarkers is clinically necessary to improve treatment strategies. Multidrug resistance-associated protein 1 (MRP1) and platelet count are linked to a poor prognosis in various types of cancer. However, it is unknown whether MRP1 or platelet count is a suitable prognostic indicator of NSCLC. In the present study, 427 patients with operable NSCLC were enlisted. The association of MRP1 expression and platelet count with clinical pathological factors and patient outcome was evaluated. MRP1 expression was found to be significantly associated with sex, histological type and tumor differentiation, while platelet count was significantly associated with smoking behavior, histological type and clinical stage. Platelet count was significantly higher in patients with negative MRP1 expression than in those with positive MRP1 expression. Survival analysis indicated that there was no association between MRP1 expression and disease-free survival (DFS) or overall survival (OS) time. In the patients with no lymph node metastasis, the OS time was significantly longer in patients with positive MRP1 expression than in those with negative expression. However, in the patients with lymph node metastasis, the DFS time was significantly shorter in patients with positive MRP1 expression than in those with negative expression. There was an association between the platelet count and DFS and OS times, which were significantly longer in patients with a normal platelet count than in those with thrombocytosis. In conclusion, MRP1 expression and platelet count are valuable independent prognostic biomarkers for survival in operable NSCLC.