Intratumoral heterogeneity and immunotherapy resistance: clinical implications

Area of Science:

• Oncology
• Immunology
• Genetics

Background:

• Immunotherapy, particularly immune checkpoint inhibitors, shows incomplete clinical success, necessitating research into resistance mechanisms.
• Resistance to immunotherapy can be innate or acquired, with common cellular and molecular pathways observed in both.
• Tumor-immune microenvironment interactions drive tumor evolution and select for variants contributing to resistance.

Purpose of the Study:

• To review the evidence linking intratumoral heterogeneity (ITH) to immunotherapy resistance.
• To explore how ITH influences tumor adaptation and immune evasion.
• To discuss strategies for overcoming immunotherapy resistance by targeting ITH.

Main Methods:

• Review of existing literature on immunotherapy resistance and ITH.
• Analysis of cellular and molecular mechanisms underlying resistance.
• Discussion of therapeutic approaches targeting ITH.

Main Results:

• ITH, shaped by tumor-immune coevolution, contributes to resistance by promoting tumor adaptation and immune evasion.
• Both tumor-intrinsic ('hardware') and tumor-extrinsic ('software') resistance mechanisms are influenced by ITH.
• Current methods for measuring and utilizing ITH in cancer management are limited.

Conclusions:

• ITH is a critical factor in immunotherapy resistance, impacting tumor evolution and immune evasion.
• Integrating ITH assessment into clinical practice is essential for designing effective therapeutic strategies.
• Future approaches should focus on targeting ITH-driven resistance mechanisms, including immunotherapy combinations and novel immunoregulatory targets.