8500 Background: The role of adjuvant chemotherapy for pathological stage I non-small cell lung cancer (NSCLC) is controversial. The purpose of this study was to investigate the effect of adjuvant chemotherapy for pathological stage I NSCLC with high-risk factors for recurrence. Methods: Prospectively collected data from 1,278 patients with pathological stage I (8th edition) NSCLC undergoing lobectomy were retrospectively analyzed. High-risk factors for recurrence were determined by multivariable Cox proportional hazards model for recurrence-free survival (RFS). RFS, overall survival (OS), and cancer-specific survival (CSS) were compared between patients who received adjuvant chemotherapy and those who did not. Results: In multivariable analysis, age (≥70 y; hazard ratio [HR], 2.14), invasive component size ( > 2 cm; HR, 1.60), visceral pleural invasion (HR, 1.81), lymphatic permeation (HR, 1.67), and vascular invasion (HR, 2.78) were identified as independent factors for RFS. In patients with high-risk factors for recurrence such as invasive component size of > 2 cm, visceral pleural invasion, lymphatic permeation, or vascular invasion (high-risk group; n = 641), RFS was significantly different between patients who received adjuvant chemotherapy (n = 222; 5-y RFS, 81.4%) and those who did not (n = 418; 5-y RFS, 73.8%; P = 0.023). OS and CSS were also significantly better in patients who received adjuvant chemotherapy (5-y OS, 92.7%; 5-y CSS, 95.0%) than in those who did not (5-y OS, 81.7%; P < 0.0001; 5-y CSS, 89.5%; P = 0.012). In patients without any high-risk factors for recurrence (low-risk group; n = 637), RFS was not significantly different between patients who received adjuvant chemotherapy (n = 83; 5-y RFS, 98.1%) and those who did not (n = 554; 5-y RFS, 95.7%; P = 0.30). OS and CSS were also not significantly different between patients who received adjuvant chemotherapy (5-y OS, 98.0%; 5-y CSS, 100%) and those who did not (5-y OS, 95.6%; P = 0.35; 5-y CSS, 99.4%; P = 0.52). Conclusions: Adjuvant chemotherapy may improve survival in patients with pathological stage I NSCLC who have high-risk factors for recurrence such as invasive component size of > 2 cm, visceral pleural invasion, lymphatic permeation, or vascular invasion.
Adjuvant chemotherapy provided survival benefit for stage T2N0 gastric cancer with high-risk factors
