[Importance of tumour mutation burden testing]

Area of Science:

• Oncology
• Immunotherapy
• Genomics

Background:

• Immune checkpoint inhibitors (ICIs) offer survival benefits for non-small-cell lung carcinoma (NSCLC) patients over chemotherapy.
• However, the overall response rate to ICIs in NSCLC remains limited at approximately 20%.

Purpose of the Study:

• To highlight the importance of predictive biomarkers for identifying patients likely to benefit from ICI therapy.
• To discuss tumor mutation burden (TMB) as a promising biomarker for ICI efficacy in NSCLC.

Main Methods:

• Review of current literature on biomarkers for ICI therapy in NSCLC.
• Analysis of the role of PD-L1 expression, tumor mutation burden (TMB), and microsatellite instability (MSI) as predictive markers.
• Examination of studies correlating MSI and TMB, and TMB thresholds for improved outcomes.

Main Results:

• PD-L1 expression has shown limitations in predicting ICI efficacy.
• Tumor mutation burden (TMB), defined as mutations per megabase, and microsatellite instability (MSI) are emerging predictive biomarkers.
• A TMB of at least 10 mutations per megabase is associated with improved progression-free survival in NSCLC patients.

Conclusions:

• Biomarkers are crucial for optimizing ICI therapy selection in NSCLC.
• High TMB is a significant predictive factor for improved treatment outcomes in NSCLC patients receiving ICIs.