Clinicopathologic study of resected, peripheral, small-sized, non-small cell lung cancer tumors of 2 cm or less in diameter: Pleural invasion and increase of serum carcinoembryonic antigen level as predictors of nodal involvement

Objective: The number of surgical interventions for small-sized lung cancer has increased with the development of computed tomography. We attempted to identify clinicopathologic characteristics of peripheral, small-sized, non-small cell lung cancer to show the limitation of partial resection or segmentectomy. Methods: A retrospective analysis of 143 patients who underwent a complete resection for a peripheral non-small cell lung cancer of 2 cm or less in diameter was performed. The relationships between nodal involvement and other clinical factors were also assessed in patients who underwent a lobectomy plus node dissection. Results: The overall 5-year survival rate was 88.1%. The 5-year survival rate was 100% for patients with a tumor of 1.5 cm or less. Survival for patients with adenocarcinoma histology was significantly better than for those with nonadenocarcinoma histology (P=.03). The 5-year survival rate for patients without lymph node metastases was 91.6%, whereas it was 62.5% for those with nodal involvement (P<.01). Increase of prethoracotomy serum carcinoembryonic antigen level was an independent predictor of a poor prognosis. Lymph node metastasis was significantly increased in those with pleural invasion by the primary lesion and increased serum carcinoembryonic antigen level. Fourteen (16.9%) of 83 patients with a tumor diameter of larger than 1.5 cm had nodal metastasis. Conclusions: Nodal involvement should be considered in patients with non-small cell lung cancer of 2 cm or less in diameter who show pleural invasion or an increased carcinoembryonic antigen level. A lobectomy with node dissection is recommended for patients with a tumor larger than 1.5 cm, suspected pleural invasion, or prethoracotomy carcinoembryonic antigen level increase.