Is adjuvant chemotherapy beneficial in NSCLC patients over 75? Insights from a retrospective analysis.

Background: Lung cancer remains the leading cause of cancer-related mortality worldwide. In resected stage II-III Non-Small Cell Lung Cancer (NSCLC), adjuvant chemotherapy (ACT) improves survival, but its benefit in elderly patients remains unclear due to the lack of dedicated studies. We conducted a retrospective study to assess benefit and predictive factors of ACT in NSCLC patients over 75-years-old.

Methods: We conducted a single-centre retrospective study at Marseille University Hospital using the EPITHOR database. Patients over 75-year-old who underwent anatomical lung resection with a theoretical ACT indication were included between 2013 and 2022. Survival outcomes were compared between ACT and non-ACT groups. The primary endpoint was 5-year mortality without recurrence, with relapse as a competing event. Exploratory outcome were 5-year overall survival and risk factors for recurrence.

Results: Among 129 eligible patients, 36 received ACT and 93 did not. ACT group patients were younger, had a more favourable perioperative course, and were more likely to have lymph node-positive disease (N+) (63.9 % vs. 43.0 %, p = 0.031), especially N2 involvement. ACT significantly decreased mortality without recurrence in univariate analysis (HR = 0.257 [95 % CI: 0.080-0.819], p = 0.022), but this benefit disappeared in multivariate analysis (HR = 0.461 [95 % CI: 0.144-1.473], p = 0.191). Similarly, ACT was associated with lower overall mortality in univariate analysis but lost significance in multivariate analysis.

Conclusion: Oncologists preferentially offer ACT to healthier elderly patients with N+ status. While ACT appears feasible, its benefit must be balanced considering competing risks of death in elderly patients. Identifying high-risk subgroups, including those with N2 disease, is crucial to refine treatment strategies in this population.