Objective   To investigate the expression and clinical significance of miR-150 in non-small cell lung cancer (NSCLC).

  Methods  Probe-based stem-loop quantitative reverse-transcriptase polymerase chain reaction was used to detect the miR-150 expression in peripheral blood mononuclear cells (PBMC) of 64 patients with NSCLC and 26 healthy individuals, and the relationship between miR-150 level and clinicopathological factors was explored.

  Results   miR-150 expressions in PBMC specimens between the cancer patients and the healthy individuals was not significantly different (P=0.260). The miR-150 expression in lung adenocarcinoma patients was significantly higher than that in healthy individuals (P=0.001). miR-150 expressions between the adenocarcinoma and squamous cells in NSCLC showed very strong differences (P=0.000). miR-150 expressions showed low discriminative ROC curve profiles, distinguishing NSCLC patients from healthy subjects by the area under the ROC curve (AUC) at 0.610 (95% CI 0.493 to 0.728) (P =0.060). High expression of miR-150 was identified as a moderately specific marker for lung adenocarcinoma, distinguishing patients from healthy subjects with AUC at 0.834 (95 % CI 0.734 to 0.934) (P=0.000). Additionally, miR-150 was identified as a highly specific marker for adenocarcinoma distinguished from squamous cell carcinoma in NSCLC with AUC at 0.951 (95% CI 0.903 to 0.999) (P=0.000). The miR-150 level was significantly associated with distant metastasis (P=0.014). No association was found between miR-150 and other clinicopathological features, such as clinical stage and lymphatic metastasis.

  Conclusion  miR-150 expression in PBMC specimens is significantly increased in lung adenocarcinoma patients. miR-150 can be a highly accurate marker for differentiating adenocarcinoma from squamous cell carcinoma in NSCLC.