Predictors of lymph node and intrapulmonary metastasis in clinical stage IA non-small cell lung carcinoma

BACKGROUND: The feasibility of limited surgical resection for clinical stage IA non-small cell lung cancer still remains controversial. METHODS: From July 1987 through April 1998, 389 patients with clinical stage IA disease underwent major lung resection and complete mediastinal lymph node dissection. Univariate and multivariable analyses were performed to determine predictors of local or regional tumor spread: pathologic lymph node involvement, intrapulmonary metastases, and lymphatic invasion. RESULTS: Of the 389 patients, 88 (23%) had lymph node involvement or intrapulmonary metastases pathologically. According to multivariable analyses, grade of differentiation and pleural involvement were significant predictors of local or regional tumor spread (p < 0.01). Based on these results, more than 40% of clinical stage IA non-small cell lung cancer patients showed pathologic lymph node involvement or intrapulmonary metastases, or both, if the patients had both of the predictors of pathologic local or regional involvement: moderate or poor differentiation of the primary tumor and pleural involvement by tumor cells. CONCLUSIONS: Limited surgical resection is not feasible for clinical stage IA non-small cell lung cancer, especially when the tumor shows moderate or poor differentiation, or pleural involvement.