Objective: Using the LUNX-mRNA as a marker and RT-PCR technique to assess mediastinal lymph nodes in patients with operable NSCLC, to evaluate at gene level the feasibility of this method in detection of micrometastasis in NSCLC and the necessity of systematic mediastinal lymphadenectomy during surgery.
Methods: Twenty patients with operable NSCLC were involved in this study. The mediastinal lymph nodes were taken during operation. RT-PCR assay was carried out to detect the LUNX-mRNA. Ten cases with benign lung disease were assayed by the same method as control.
Results: Seventy one mediastinal lymph nodes were obtained from 20 patients, 8 (11.3%) of which showed histologically metastasis with HE staining, while 23 (32.4%) were LUNX-mRNA positive by RT-PCR, P < 0.001. Micrometastasis was detected in 25.4% of all lymph nodes. LUNX-mRNA was found to be positive in 23.6% of lymph nodes from 15 patients with stage I A-II B NSCLC compared with 62.5% from 5 patients with stage III NSCLC, with a significant difference (P = 0.003).
Conclusion: About 25.4% of mediastinal lymph nodes are with micrometastasis in patients with operable NSCLC. Systematic mediastinal lymphadenectomy is necessary to deal with the regional lymph nodes during surgery.