Should subcarinal lymph nodes be routinely examined in patients with non-small cell lung cancer?

This study is based on a retrospective analysis of 163 patients with stage III non-small cell lung cancer randomized to one of three Lung Cancer Study Group postoperative resection-adjuvant treatment protocols. All patients underwent rigorous surgical/pathologic staging including required removal and examination of bronchopulmonary, hilar, subcarinal, and paratracheal lymph nodes. Patients were grouped as follow: group I, only subcarinal nodes diseased (N = 40); group II, only high paratracheal nodes diseases (N = 32); group III, only mid-mediastinal nodes diseased (N = 48); and group IV, subcarinal nodes plus nodes from any other site diseased (N = 43). Patient deaths and tumor recurrences were recorded. The death rate was highest for patients with metastases to subcarinal nodes plus nodes in another site (group IV). Pairwise comparisons of the survival rates of patients in each group disclosed a significant difference between groups III and IV (p < 0.02). In view of this observation, the Lung Cancer Study Group recommends that all patients have rigorous mediastinal lymph node staging done at the time of pulmonary resection to establish prognosis and criteria for study of adjuvant treatment interventions.