STUDY OBJECTIVE: The details of lobar lymph node metastases at the root of nonprimary lobes (NPLs) in patients with lung cancer are still unclear. DESIGN: A prospective study from February 1989 to November 2000. Lobar lymph nodes in primary lobes (PLs) and NPLs were evaluated regardless of the location of the primary tumor. PATIENTS: Two hundred forty-eight patients who underwent surgery and had no involvement of the adjacent lobe by primary tumor were enrolled in this study. MEASUREMENTS AND RESULTS: Lobar lymph node metastases were observed in 53 patients (21.4%), with frequencies not different among the primary sites. Thirty-seven patients had lobar lymph node metastases limited to the PL, and 16 patients had metastases in the NPLs. The frequencies of lobar lymph node metastases in NPLs were not affected by histologic type or T classification, but they were dependent on laterality and proximal lymph node metastases. On the right side, lobar lymph node metastases in NPLs were observed in 9.0% of all 155 patients, in 45.2% of 31 patients with lobar lymph node metastases, and in 34.3% of 35 patients with mediastinal lymph node metastases. They were significantly higher in the patients with interlobar/hilar lymph node metastases (12 of 28 patients) or with mediastinal metastases (12 of 35 patients) than in those without metastases on the right (p < 0.0001, respectively). CONCLUSIONS: Lobar lymph node metastases in NPLs were frequent on the right side and became more frequent according to the prevalence of the proximal lymph node metastases, rather than the clinicopathologic properties of the primary tumor itself.
STUDY OBJECTIVE: The details of lobar lymph node metastases at the root of nonprimary lobes (NPLs) in patients with lung cancer are still unclear. DESIGN: A prospective study from February 1989 to November 2000. Lobar lymph nodes in primary lobes (PLs) and NPLs were evaluated regardless of the location of the primary tumor. PATIENTS: Two hundred forty-eight patients who underwent surgery and had no involvement of the adjacent lobe by primary tumor were enrolled in this study. MEASUREMENTS AND RESULTS: Lobar lymph node metastases were observed in 53 patients (21.4%), with frequencies not different among the primary sites. Thirty-seven patients had lobar lymph node metastases limited to the PL, and 16 patients had metastases in the NPLs. The frequencies of lobar lymph node metastases in NPLs were not affected by histologic type or T classification, but they were dependent on laterality and proximal lymph node metastases. On the right side, lobar lymph node metastases in NPLs were observed in 9.0% of all 155 patients, in 45.2% of 31 patients with lobar lymph node metastases, and in 34.3% of 35 patients with mediastinal lymph node metastases. They were significantly higher in the patients with interlobar/hilar lymph node metastases (12 of 28 patients) or with mediastinal metastases (12 of 35 patients) than in those without metastases on the right (p < 0.0001, respectively). CONCLUSIONS: Lobar lymph node metastases in NPLs were frequent on the right side and became more frequent according to the prevalence of the proximal lymph node metastases, rather than the clinicopathologic properties of the primary tumor itself.