High expression of M3 muscarinic acetylcholine receptor is a novel biomarker of poor prognostic in patients with non-small cell lung cancer.

We assessed the expression of M3 receptor in non-small cell lung cancer (NSCLC) and determined its relationship with clinicopathological features and its impact on patient outcome. Specimens from 192 patients with NSCLC were investigated by immunohistochemistry for M3 receptor and Ki67 expression. Correlation between the expression of M3 receptor and Ki67 and various clinicopathological features of NSCLC patients was analyzed. We found that M3 receptor expression was gradually elevated from normal to metaplasia/dysplasia tissues to cancer tissues. Furthermore, there was a similar trend for Ki67 expression. Statistical analysis revealed that M3 receptor expression in tumor cells were correlated significantly with stage (P < 0.0001), histology type (P = 0.0003), Ki67 expression (P < 0.0001), tumor size (P < 0.0001), lymph node status (P < 0.0001), LVS invasion (P = 0.0002), and histology grade (P < 0.0001). Patients with M3 receptor high expression showed far lower disease-free survival (DFS) and overall survival (OS) rates than those with M3 receptor low expression. Multivariate Cox regression analysis demonstrated that high M3 receptor expression was an independent prognostic factor for both DFS and OS. High M3 receptor expression correlates with poor survival in NSCLC patients. M3 receptor expression may be related with tumor progression in NSCLC, indicating that M3 receptor may be a novel antineoplastic target in the future.