Sex-biased molecular differences in lung adenocarcinoma are ethnic and smoking specific

BACKGROUND

Sex-related differences in cancer epidemiology, tumor biology, immune system activity, and pharmacogenomics have been suggested to be important considerations for precision cancer control. Here we elucidated systematically sex biases in genetic variants, gene expression profiles, and immunological landscapes of lung adenocarcinoma patients (LUADs) with different ancestry and smoking status.

METHODS

Somatic mutation and mRNA expression data of Asian and Non-Asian LUADs were obtained from public databases. Sex-biased genetic mutations, gene expression, biological pathways, and immune infiltration were identified in the context of smoking status and race.

RESULTS

Among nonsmokers, male-biased mutations were prevalent in Asian LUADs, while few sex-biased mutations were detected in Non-Asian LUADs. EGFR was the only mutation whose frequency was significantly higher in females than males in both Asian and Non-Asian nonsmokers. More genes exhibited sex-biased expression in Non-Asian LUADs compared to Asian LUADs. Moreover, genes distinctly expressed in females were mainly related to immune-related pathways, whereas those in males were more involved in activation of DNA repair, E2F_targets, and MYC_targets pathways. We also detected sex-specific immune infiltration in the context of genetic variation. In EGFR-mutant LUADs, males had a significantly increased infiltration of CD8 + T cells, whereas resting CD4 + memory T cells were more abundant in females. Additionally, in KRAS-mutant LUADs, CD8 + and CD4 + T cells were more abundant in females than males. In addition, we detected all female patients with high SCGB3A2 expression were exclusively sensitive to immunotherapy, while this phenomenon was not observed in male patients.

CONCLUSIONS

Our findings provided evidence that sex-related molecular and cellular components are involved in shaping tumor distinct genetic and immune features, which might have important impact on personalized targeted and immune therapy.

Immune checkpoint inhibitors in driver mutation-positive nonsmall cell lung cancer: is there a role?

PURPOSE OF REVIEW

Despite advances in immunotherapy for nonsmall cell lung cancer patients, the clinical efficacy of drugs for patients with oncogenic driver mutations remains limited. This article aimed to comprehensively review the currently available data on the efficacy and safety of immune checkpoint blockade (ICB) for patients with driver mutation-positive lung cancer.

RECENT FINDINGS

Despite the positive interaction between activation of oncogenic pathways and upregulated PD-L1 expression demonstrated in preclinical studies, the efficacy of single-agent ICB in patients with oncogenic mutation has largely been discouraging, except for those with KRAS mutations. The combination therapies using ICB with tyrosine kinase inhibitors (TKIs) for EGFR/ALK alteration raised a concern for the high incidence of treatment-related adverse events, notably hepatotoxicity and interstitial lung disease. A novel combination with bevacizumab demonstrated promising efficacy with tolerable safety profiles.

SUMMARY

Other than patients with the KRAS mutation who demonstrate relatively favorable response to ICB, a single-agent ICB therapy should be considered for those who retain good performance status but have no other therapeutic options available. Further studies on the combination of ICB and TKI are needed to identify the most viable pair regarding safety. Additional studies using novel combination partners, such as anti-VEGF inhibitors, are also warranted.