Prognostic factors in 3315 completely resected cases of clinical stage I non-small cell lung cancer in Japan

Background: The objective of this retrospective study was to identify prognostic factors in completely resected clinical (c-) stage I non-small cell lung cancer cases. Methods: In 2001, the Japanese Joint Committee of Lung Cancer Registry collected data on the outcome and clinicopathological profiles of 7408 patients who had undergone resection for primary lung cancer in 1994. They included 3315 c-stage I patients who underwent complete resection, and in this study attempted to identify prognostic factors in the c-stage IA and c-stage IB cases. Results: The overall 5-year survival rate was 66.5%: 74.7% in the 2085 c-stage IA cases and 52.5% in the 1230 c-stage IB cases. The survival curve of the c-stage IA cases was higher than that of the c-stage IB cases. Multivariate analysis of the c-stage IA cases revealed six factors that predicted a significantly better outcome: age, gender, pathological (p-) T status, p-N status, nodal dissection, and tumor diameter (: 2 cm), and the same analysis of the c-stage IB cases revealed six factors: age, gender, p-T status, p-N status operative procedure, and tumor diameter (< 5 cm). The c-stage I patients whose tumor diameter was 2 cm or less had a higher survival rate than the patients whose turner diameter was more than 2 cm, and the c-stage IB patients whose tumor diameter was less than 5 cm had a higher survival rate than the patients whose tumor diameter was 5 cm or more. Conclusion: Tumor size is an independent prognostic factor for postoperative survival in c-stage 1 patients.