Background: Adjuvant chemotherapy could improve the prognosis of stage II-III non-small cell lung cancer (NSCLC). However, its influences on stage IB were controversial. The purpose of this study was to investigate whether patients with stage IB NSCLC could benefit from adjuvant chemotherapy.
Methods: Stage IB NSCLC in 2010-2015 was selected from the surveillance, epidemiology, and end result database. Chi square test was used to compare the clinical characteristics of patients with different adjuvant chemotherapy status. Kaplan-Meier survival curves were plotted by the log-rank test. Cox proportional hazard regression was used to perform multivariate analysis on overall survival (OS), and the life table method was employed to calculate 1-, 3-, and 5-year survival rates.
Results: A total of 2915 patients were included in this study, and the number of patients with visceral pleural invasion (VPI) was 1096 (37.6%), of which 145 (13.2%) received adjuvant chemotherapy. There was no statistical difference in OS among the total population with or without chemotherapy (p = 0.295), nor in patients with VPI (p = 0.216). In patients with VPI, the 1-, 3-, 5-year survival curves of patients who are receiving adjuvant chemotherapy showed an upward trend compared with patients who did not. Additionally, female, high differentiated, adenocarcinoma, and tumor size ≤ 3 cm were also independent prognostic factors for improving the prognosis of patients with VPI.
Conclusion: In our study, stage IB NSCLC did not benefit from adjuvant chemotherapy, even in patients with VPI. However, the significance of adjuvant chemotherapy in patients with VPI is still worth further exploration.
Keywords: Adjuvant chemotherapy; NSCLC; Visceral pleural invasion.