Association of TP53 Mutation Status and Sex with Clinical Outcome in NSCLC Treated with Immune Checkpoint Inhibitors: A Retrospective Cohort Study.

Purpose: Some studies suggest that TP53 mutations are associated with the response to immune checkpoint inhibitors (ICI) in patients with non-small cell lung cancer (NSCLC) and also contribute to sex disparities in several cancers. Thus, we hypothesized that TP53 mutations might serve as sex-dependent genomic biomarkers of ICI treatment response in patients with NSCLC.

Materials and methods: Clinical data of 100 patients with metastatic NSCLC treated with ICI monotherapy at Seoul National University Bundang Hospital (SNUBH) were retrospectively reviewed. Genomic and clinical datasets of TCGA and an ICI-treated lung cancer cohort (cBioPortal) were also analyzed.

Results: In SNUBH cohort, no statistically significant difference was observed in disease control rate per the TP53 mutation status (p=0.503); however, female patients with TP53 mutated (MT) had a significantly prolonged median progression-free survival (PFS) compared to wild-type (WT) (6.1 months in TP53 MT vs. 2.6 months in TP53 WT; p=0.021). PD-L1 high (≥50%) expression was significantly enriched in female patients with TP53 MT (p=0.001). The analysis from publicly available dataset also revealed that females with NSCLC with TP53 MT showed significantly longer PFS than those with TP53 WT (p<0.001). In TCGA analysis, expression of immune-related genes, and TMB score in TP53 MT females were higher than in males without TP53 MT.

Conclusion: Female patients with NSCLC with TP53 mutations had high PD-L1 expression and showed favorable clinical outcomes following ICI therapy, suggesting a need for further research to explore the role of TP53 mutations for sex disparities in response to ICI therapy.