Revisiting immune escape in colorectal cancer in the era of immunotherapy

Br J Cancer. 2019 Apr;120(8):815-818. doi: 10.1038/s41416-019-0421-x. Epub 2019 Mar 13.

Abstract

In colorectal cancer (CRC), T-cell checkpoint blockade is only effective in patients diagnosed with mismatch repair-deficient (MMR-d) cancers. However, defects in Human Leukocyte Antigen (HLA) class I expression were reported to occur in most MMR-d CRCs, which would preclude antigen presentation in these tumours, considered essential for the clinical activity of this immunotherapeutic modality. We revisited this paradox by characterising HLA class I expression in two independent cohorts of CRC. We determined that loss of HLA class I expression occurred in the majority (73-78%) of MMR-d cases. This phenotype was rare in CRC liver metastases, irrespective of MMR status, whereas weak, inducible expression of HLA class I molecules was frequent in liver lesions. We propose that HLA class I is an important determinant of metastatic homing in CRCs. This observation is paramount to understand CRC carcinogenesis and for the application of immunotherapies in the metastatic setting.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigen Presentation / immunology
  • Brain Neoplasms / genetics
  • Brain Neoplasms / immunology
  • Carcinogenesis / genetics
  • Carcinogenesis / immunology
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / immunology
  • Colorectal Neoplasms / pathology
  • Colorectal Neoplasms / therapy*
  • Female
  • Gene Expression Regulation, Neoplastic / immunology
  • Genes, MHC Class I / genetics*
  • Genes, cdc / drug effects
  • Genes, cdc / immunology
  • Humans
  • Immunotherapy*
  • Liver / metabolism
  • Liver / pathology
  • Male
  • Middle Aged
  • Neoplasm Metastasis
  • Neoplastic Syndromes, Hereditary / genetics
  • Neoplastic Syndromes, Hereditary / immunology
  • T-Lymphocytes / immunology*

Supplementary concepts

  • Turcot syndrome