The real-world comparison of non-small cell lung cancer survival outcomes depending on immunotherapy treatment and PD-L1 expression level

The incidence and mortality trends of lung cancer in Slovakia are not favorable. In our single-center, non-interventional retrospective cohort study, we provide comprehensive information about Slovakia's non-small cell lung cancer (NSCLC) patient population. We evaluated how the introduction of immunotherapy agents affected the survival of NSCLC patients and tried to identify whether the PD-L1 expression level was associated with a negative patient survival effect. The demographics, results of histological and immunohistochemical (PD-L1) examinations, and information about treatment (immunotherapy or standard of care (SOC)) were recorded. In males, squamous cell carcinomas occurred more often than adenocarcinomas (54.40% and 45.08%, respectively), in females, adenocarcinomas clearly dominated (71.88% vs. 27.08%, respectively). The overall proportion of adenocarcinomas was 53.98%. NSCLC patients with stage III and IV treated with SOC treatment (n=54) showed significantly worse overall survival than patients with immunotherapy (n=9) (p=0.026). The comparison of immunotherapy-treated (n=7) and SOC-treated (n=32) adenocarcinoma patients stage III and IV showed similar results (p=0.046). The negative effect of PD-L1 expression level on survival of females with NSCLC and females with adenocarcinoma was visible already at the TPS level of 20-25%. In males with NSCLC, the negative effect was visible at a TPS level of 70-90%. Our results confirm the positive impact of immunotherapy in real-world conditions and show different effects of PD-L1 expression level on patients' survival depending on sex and histology. Determination of different PD-L1 expression breaking points in males and females with NSCLC is a solid starting point for more research on this topic.