Study objective: The details of lobar lymph nodemetastases at the root of nonprimary lobes (NPLs) in patients with lungcancer are still unclear.
Design: A prospective studyfrom February 1989 to November 2000. Lobar lymph nodes in primary lobes(PLs) and NPLs were evaluated regardless of the location of the primarytumor.
Patients: Two hundred forty-eight patients whounderwent surgery and had no involvement of the adjacent lobe byprimary tumor were enrolled in this study.
Measurements andresults: 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 thePL, and 16 patients had metastases in the NPLs. The frequencies oflobar lymph node metastases in NPLs were not affected by histologictype or T classification, but they were dependent on laterality andproximal lymph node metastases. On the right side, lobar lymph nodemetastases in NPLs were observed in 9.0% of all 155 patients, in45.2% of 31 patients with lobar lymph node metastases, and in 34.3%of 35 patients with mediastinal lymph node metastases. They weresignificantly higher in the patients with interlobar/hilar lymph nodemetastases (12 of 28 patients) or with mediastinal metastases (12 of 35patients) than in those without metastases on the right (p < 0.0001,respectively).
Conclusions: Lobar lymph nodemetastases in NPLs were frequent on the right side and became morefrequent according to the prevalence of the proximal lymph nodemetastases, rather than the clinicopathologic properties of the primarytumor itself.