Completely resected stage IIIA non-small cell lung cancer: The significance of primary tumor location and N2 station

Background: The number of N2 stations (single vs multiple N2 stations) is a n important prognostic factor in patients with completely resected stage II IA-N2 non-small cell lung cancer. However, the significance of both the N2 station(s) actually involved and the primary tumor location remains unclear . Methods: The database was built with the use of a questionnaire survey on t he survival of patients with pathologic stage IIIA-N2 non-small cell lung c ancer completely resected between January 1992 and December 1993. The surve y was performed by the Japan Clinical Oncology Group as of July 1999. The d ata include information on the survival and N2 stations of 402 patients. Results: A, frequently metastasized single N2 station was the lower pretrac heal station in primary tumors in the right upper lobe, the subaortic stati on in the left upper lobe, and the subcarinal station in the right middle o r lower lobe and the left lower lobe. In multiple N2 stations, the frequenc y of metastasis of the N2 station observed in a single N2 station was as hi gh as 72% to 89%, and one or two other frequently metastasized stations wer e added to each group. Regarding the survival of patients with a primary tu mor in each lobe except for the left lower lobe, a single N2 station result ed in a significantly better survival than did multiple N2 stations. Furthe rmore, the overall survivals classified according to each primary site show ed a significant difference among the four primary sites (P =.04). Conclusions: The primary tumors in each lobe showed a prevalence of N2 stat ion(s). The number of N2 stations is a good prognosticator except in patien ts with a primary tumor in the left lower lobe. In addition, the site of a primary tumor itself is also considered to influence the survival of the pa tients.