Objective  This work investigates the diagnostic significance of fine needle aspiration cytology (FNAC) and LunX mRNA for lymph node metastasis in lung cancer.

  Methods  FNAC was used to examine the lymph nodes of lung cancer patients; quantitative real-time reverse transcription polymerase chain reaction (RT - PCR) was employed to determine the LunX mRNA levels in the biopsy materials. Both these methods could detect whether lymph node metastasis occurred among lung cancer patients.

  Results  In examining the lymph nodes, LunX mRNA was detected in 84.8% of the patients with lung cancer, whereas only in 5 % patients in the control group (χ² = 37.16, P < 0.01). LunX mRNA Objective: copies in the group with metastatic lung cancer were significantly different with the control group (Z = - 5.807, P < 0.01). Furthermore, the positive rates for LunX mRNA in different histologic types were as follows: 86.3 % (19 / 22) in metastatic squamous cell carcinoma, 70.6 % (12 / 17) in adenocarcinoma, 75 % (3 / 4) in small cell carcinoma, and 66.7 % (2 / 3) in poorly differentiated carcinoma. No significant difference was observed in the statistical data (P = 0.482) and LunX mRNA copy numbers (F = 0.377, P = 0.770) of these groups.

  Conclusion  FNAC combined with the detection of LunX mRNA levels is a minimally invasive, rapid, and accurate diagnostic method for diagnosing lymph node metastasis in lung cancer.