[Immune response and colorectal cancer]

Area of Science:

• Immunology
• Oncology
• Cancer Research

Context:

• Colorectal cancer (CRC) progression is significantly influenced by the host's immune response.
• The density of tumor infiltrating lymphocytes (TILs) is emerging as a critical prognostic biomarker in CRC, potentially surpassing traditional TNM staging.
• Specific cell-mediated immunity, involving T cell activation by dendritic cells presenting tumoral antigens, plays a vital role in controlling CRC growth.

Purpose:

• To review the intricate role of immune responses in colorectal cancer (CRC).
• To explore the prognostic significance of tumor infiltrating lymphocytes (TILs) in CRC.
• To discuss mechanisms of immune evasion and resistance in CRC and their implications for immunotherapy.

Summary:

• Tumor infiltrating lymphocytes (TILs) are crucial for controlling colorectal cancer (CRC) progression, with their rate correlating strongly with prognosis, even exceeding TNM classification.
• While specific T cell activation against tumoral antigens like carcinoembryonic antigen (CEA) is important, immunogenic neo-antigens in microsatellite unstable CRC are linked to higher TILs and better outcomes.
• Colorectal cancer (CRC) can evade immune surveillance through modulation of immune responses or development of tumor cell resistance, posing challenges for effective treatment.

Impact:

• Highlights the prognostic value of tumor infiltrating lymphocytes (TILs) in colorectal cancer (CRC), suggesting a shift from traditional staging methods.
• Identifies immunogenic neo-antigens in microsatellite unstable CRC as potential targets for enhancing anti-tumor immunity.
• Provides insights into colorectal cancer (CRC) immune evasion mechanisms, crucial for designing novel immunotherapy strategies and improving patient treatment outcomes.