Interlobar lymph node metastases according to primary tumor location in lung cancer

Abstract Interlobar lymph node metastases were analyzed in consecutive 284 lung cancer patients with lobar–hilar and mediastinal lymph node dissection. Interlobar lymph node metastases were observed in 46 (16.2%) patients with no difference between right and left cases. On the right side, there was a significant difference in the frequency of inferior interlobar lymph node metastases between upper lobe and middle/lower lobe tumors ( P =0.0004), but no difference in the frequencies of superior ones according to primary site. On the left, there was a significant difference in the frequency of interlobar lymph node metastases between upper lobe and lower lobe tumors ( P =0.0021). In per-segment analyses, the frequency of inferior interlobar lymph node metastases in segments 1–3 and 6 was significantly lower than in the other total segments ( P P =0.0008) on the left. Even limited to one lobe, the patterns of interlobar lymph node metastases were different among the segments in the right lower lobe and the left upper lobe.