Predictive factors for survival in surgically resected clinical IA peripheral adenocarcinoma of the lung

Background Patients with clinical IA (C-IA) lung cancer have a 5-year survival rate of approximately 70% after surgical therapy alone. We attempted to clarify preoperative factors that are predictive for poor prognosis after surgery among patients diagnosed with C-IA adenocarcinoma of the lung. Methods Between 1994 and April 2002, 65 patients with C-IA adenocarcinoma of the lung underwent lobectomy + hilar and mediastinal node dissection. The chest computed tomography (CT) imaging and clinicopathologic records of the patients were examined. Tumors were subtyped into solid type or nonsolid type categories according to the component of ground glass opacity assessed by CT. Age, sex, serum carcinoembryonic antigen (CEA) level, histologic subtype (replacing versus nonreplacing), and tumor size were also analyzed. Results Solid type on CT and high serum CEA level (≥4.0 ng/mL) were prognostic factors for poor outcome in univariate analyses (p< 0.05). Solid type on CT, high serum CEA level, and larger tumor size (> 20 mm) were significant (p< 0.05) prognostic factors for poor outcome in multivariate analyses. Solid type on CT and high serum CEA level were significant (p< 0.01) risk factors for lymph node involvement in both univariate and multivariate analyses. Furthermore, based on the factors of CT subtype, tumor size, and serum CEA level, the 5-year disease-free survival rate was 20.1% for patients with two of the three factors, and 21.2% even if they were assessed as pN0. Computed tomography subtype was strongly associated with histologic subtype (p< 0.0001). Conclusions Solid type on CT (associated with histologic subtype such as nonreplacing type), tumor size larger than 20 mm, and high serum CEA concentration are important preoperative predictive factors for poor outcome after surgery for patients with C-IA lung adenocarcinoma.