Objective: N1 disease in non-small cell lung cancer represents a heterogeneous patient subgroup with a 5-year survival of approximately 40%. Few reports have evaluated the correlation between N1 disease and tumor recurrence or which subgroup of patients would most benefit from adjuvant chemotherapy.
Methods: From 1997 through 2002, all patients with pathologic T1-4 N1 M0 non-small cell lung cancer who had a complete resection with systematic mediastinal lymphadenectomy were retrospectively analyzed and evaluated for factors associated with recurrence and long-term survival.
Results: One hundred eighty patients with N1 disease were evaluated. Sixty-six (37%) patients had either locoregional recurrence (n = 39 [22%]), distant metastasis (n = 41 [23%]), or both during follow-up. Univariate analysis demonstrated that visceral pleural invasion and age were associated with locoregional recurrence, whereas visceral pleural invasion, distinct N1 metastasis (as opposed to direct N1 invasion by the primary tumor), and multistation lymph node involvement were associated with distant metastasis (P < .05). Multivariable analysis demonstrated that visceral pleural invasion, multistation N1 involvement, and distinct N1 metastasis were the only independent predisposing factors for locoregional recurrence and distant metastasis. Overall 5-year survival was 42.5%. Survival was significantly decreased by advanced pathologic T classification (P = .015), visceral pleural invasion (P < .0001), and higher tumor grade (P = .014).
Conclusions: In patients with N1-positive non-small cell lung cancer, visceral pleural invasion, multistation N1 disease, and distinct N1 metastasis are independent predictors of subsequent locoregional recurrence and distant metastasis. Advanced T classification, visceral pleural invasion, and higher tumor grade were predictors of poor survival. These patients represent a subgroup of patients with N1 disease who might benefit from additional therapy, including adjuvant chemotherapy.