Is adjuvant chemotherapy for completely resected p-stage IA (>2 cm) and stage IB non-small-cell lung cancer beneficial for elderly patients? A large, retrospective cohort study based on real-world data from Japan

Objective: The efficacy of tegafur-uracil as adjuvant chemotherapy for patients with completely resected stage I non-small-cell lung cancer is proven; however, its efficacy for elderly patients remains unclear. Herein, we evaluated the effectiveness of adjuvant chemotherapy for elderly patients with completely resected stage I non-small-cell lung cancer based on real-world Japanese data using propensity score matching.

Methods: This retrospective study extracted data from a nationwide registry study, performed in 2016, on patients ≥75 years who underwent lobectomy with mediastinal nodal dissection for non-small-cell lung cancer in 2010 and were diagnosed with p-stage IA (>2 cm) or stage IB non-small-cell lung cancer. We classified the 1294 patients into two groups-Group A, postoperative adjuvant chemotherapy (n = 295, 22.8%) and Group N, no adjuvant chemotherapy (n = 999, 77.2%)-and analyzed differences in postoperative overall survival between groups.

Results: Group A showed no advantage in overall survival over Group N as a whole (hazard ratio: 0.824 [95% confidence interval: 0.631-1.076]), in p-stage IA (hazard ratio: 0.617 [95% confidence interval: 0.330-1.156]) and in p-stage IB (hazard ratio: 0.806 [95% confidence interval: 0.597-1.088]) subsets. Even after propensity score matching, Group A showed no significant advantage in overall survival over Group N as a whole (hazard ratio: 0.975 [95% confidence interval: 0.688-1.381]), in p-stage IA (hazard ratio: 1.390 [95% confidence interval: 0.539-3.586]) and in p-stage IB (hazard ratio: 0.922 [95% confidence interval: 0.633-1.343]).

Conclusions: adjuvant chemotherapy for completely resected p-stage IA (>2 cm) and stage IB non-small-cell lung cancer showed no benefit for recommendation for elderly patients; considering the risk of adverse events, we do not recommend adjuvant chemotherapy for elderly patients.