Staging in Lung Cancer: Is 3 cm a Prognostic Threshold in Pathologic Stage I Non-small Cell Lung Cancer?

Since 1974, a tumor size of 3 cm in diameter has been regarded as the prognostic threshold in the staging of bronchogenic carcinoma. To study the prognostic behavior of surgical-pathologic tumor size in non-small cell lung cancer (NSCLC) with complete resection. Four-year multi-institutional prospective study from 1993 to 1997. Consecutive cases of NSCLC in pathologic stages IA-IB (pIA-pIB) treated surgically with complete resection in hospitals belonging to the Bronchogenic Carcinoma Co-operative Group of the Spanish Society of Pneumology and Thoracic Surgery (GCCB-S). The Schoenfeld procedure was used to identify different prognostic groups, considering 1 cm as the measurement unit. Based on the 1,020 cases evaluated, four prognostic groups were identified: 0 to 2 cm (group A; n = 147), 2.1 to 4 cm (group B; n = 448), 4.1 to 7 cm (group C; n = 336), and > 7 cm (group D; n = 89). At 5 years, survival was 0.63 (95% confidence interval [CI], 0.58 to 0.68), 0.56 (95% CI, 0.53 to 0.59), 0.49 (95% CI, 0.46 to 0.52), and 0.38 (95% CI, 0.32 to 0.44) for groups A, B, C, and D, respectively. Differences between paired groups (log-rank) were significant: 0.0074 between groups A and B, 0.0048 between groups B and C, and 0.0034 between groups C and D. In initial stages (pIA-pIB) of NSCLC, the 3-cm value was not found to behave as a prognostic threshold; in this study, four surgical-pathologic tumor size groups were identified with strong prognostic differences: from 0 to 2 cm, from 2.1 to 4 cm, from 4.1 to 7 cm, and > 7 cm.