Implications of Staging in Lung Cancer

¹ From the Division of Thoracic Surgery, National Cancer Center Hospital, Tokyo, Japan

Lung cancer staging, based on anatomic extent of disease and described by the TNM staging system (T, primary tumor; N, regional lymph nodes; M, distant metastasis), is an important parameter for determining the clinical course of this disease. To evaluate the prognostic importance of TNM staging for lung cancer, we conducted a retrospective study analyzing survival rates according to TNM staging in 2,382 patients who had pulmonary resection for non-small cell lung cancer. Postoperatively, 3 patients were classified in stage 0, 796 in stage I, 304 in stage II, 719 in stage IIIA, 233 in stage IIIB, and 327 in stage IV. The 5-year survival rates for these patients were as follows: stage I, 68.5%; stage II, 46.9%; stage IIIA, 26.1%; stage IIIB, 9.0%; and stage IV, 11.2% (including ipsilateral, intrapulmonary metastases); 5-year survival rates for 140 patients with stage IV disease with intrapulmonary metastases in either the same lobe or another ipsilateral lobe were 17.8% and 8.3%, respectively. There was prognostic significance between stage I and stage II disease, stage II and stage IIIA disease, and stage IIIA and stage IIIB disease, but not between stage IIIB and stage IV disease. Only a few modifications will be required for the TNM staging system, which at present accurately reflects the prognosis of patients with lung cancer and is helpful in determining treatment.