Prognostic variability among nonsmall cell lung cancer patients with pathologic N1 lymph node involvement - Epidemiological figures with strong clinical implications

BACKGROUND. Patients who have nonsmall cell lung cancer with N1 lymph node status are an intermediate group of patients who have a variable prognosis. Differences in lymph node level (hilar or pulmonary lymph nodes) may influence patient survival. The authors retrospectively analyzed the factors that influenced prognosis, including the level of NI lymph node involvement. METHODS. The authors used the Tuscan Cancer Registry archives to retrieve records on 2523 patients who had lung tumors diagnosed during the period from 1996 and 1998 in the provinces of Florence and Prato, central Italy. To analyze the survival of patients according to the level of lymph node involvement, the prognoses of patients with nonsmall cell lung cancer who had N1 lymph node status were compared in a population-based case series. Among 112 patients with pathologic N1 status, the following variables were analyzed for their influence on postoperative survival: gender, age, cell type, pathologic tumor status, the number of metastatic lymph nodes, the level of metastatic lymph nodes (hilar or pulmonary), and the type of surgical resection. RESULTS. The 5-year survival rates for patients who had involvement of pulmonary and hilar lymph nodes were 41.2% and 21.8%, respectively (P =.005). A Cox proportional hazards model analysis indicated that the presence of hilar lymph node involvement was an independent prognostic factor. CONCLUSIONS. N1 pathologic lymph node status was identified in a combination of subgroups with different prognoses, and the presence of hilar lymph node disease had prognostic significance. This difference in survival may lead to the use of different therapies for these subgroups of patients with pathologic N1 nonsmall cell lung cancer.