Involvement of lymphatic metastatic spread in non-small cell lung cancer accordingly to the primary cancer location

Objectives: The purpose of the study is to investigate the contribution of lymphatic spread in operable non-small cell lung cancer (NSCLC) in relation to the cancer location. Methods: We retrospectively studied 557 consecutive patients [514 mates and 43 females, mean age 62.5 +/- 9.1 years (range, 20-84)] who underwent a major lung resection due to NSCLC in our department, from January 1995 to December 1999. Preoperative staging for metastatic disease was negative. Extended mediastinal lymph node dissection was performed in all lung resections. Results: The pathology report revealed 220 adenocarcinomas, 276 squamous-cell, 34 undifferentiated, 25 adenosquamous and 2 large-cell carcinomas. The TNM stage was IA in 52 patients, IB in 109, IIA in 20, IIB in 146, IIIA in 190, IIIB in 35 and IV in 5. The classification of disease was NO in 240 (40.1%) patients, N1 in 179 (32.1%) and N2 in 138 (24.8%). Twenty-eight patients (5.03%) presented a skip metastasis to hilar lymph nodes, while 27 patients (4.85%) presented with skip metastasis to the mediastinum. The size of the primary tumors presenting with metastases was significantly smaller in adenocarcinomas compared to squamous-cell carcinomas (P = 0.046). Regarding the right lung, tumors originating in the upper lobe mainly metastasized to [eve[ No. 4, white tumors of the middle lobe spread to stations Nos. 4 and 7, and those in the lower lobe to level No. 7. Regarding the left lung, tumors originating in the upper lobe metastasized to level No. 5, white tumors within the tower lobe spread to stations, Nos. 7-9. Conclusions: Mediastinal lymph nodal dissection is necessary for the accurate determination of pTNM stage. It seems that there is no definite way for lymphatic spreading in relation to the location of the cancer. Skip metastasis to the mediastinal lymph nodes was present in 4.85% of our patients, while adenocarcinomas, even small-sized ones, are more aggressive than squamous-cell carcinomas. (C) 2003 Elsevier Ireland Ltd. All rights reserved.