Objective: The objective of this study was to determine the relationship between tumor size and curability of stage I non-small cell lung cancer.
Methods: From the Surveillance, Epidemiology, and End Results registry 2003, we identified all primary non-small cell lung cancer cases that were diagnosed prior to autopsy. Among these cases, we narrowed the focus to those diagnosed in 1988 or later, and to 7,620 patients who had undergone curative surgical resection. Kaplan-Meier survival curves were obtained for these stage I malignancies for five tumor size categories (ie, 5 to 15 mm, 16 to 25 mm, 26 to 35 mm, 36 to 45 mm, and > 45 mm). The 12-year Kaplan-Meier estimator of survival was used as a measure of lung cancer cure rate.
Results: Among 7,620 stage I cancers, cure rates decreased with increasing tumor size. The 12-year survival rates for patients with tumors 5 to 15 mm in diameter was 69% (95% confidence interval [CI], 64 to 74%), 63% for those with tumors 16 to 25 mm in diameter (95% CI, 60 to 67%), 58% for those with tumors 26 to 35 mm in diameter (95% CI, 54 to 61%), 53% for those with tumors 36 to 45 mm in diameter (95% CI, 48 to 57%), and 43% for those with tumors > 45 mm in diameter (95% CI, 39 to 48%). Cure rates were statistically significantly different for all tumor size categories (p < 0.05) except for the groups with tumors 26 to 35 mm and 36 to 45 mm in diameter (p = 0.10).
Conclusions: Smaller tumor size at diagnosis is associated with improved curability within stage I non-small cell lung cancers. These results suggest that further subclassification by size within stage I may be important.