Fig. 3.

Variation in the immune landscape from early- to advanced-stage CRC

The model of immune ‘hot’ and ‘cold’ tumours across the spectrum of primary and stage IV disease is illustrated, based on⁶³. Several other factors are involved, including age and sex of patient, tumour sidedness (with more dMMR in right-sided colon cancers being immune hot). Patterns of clinical scenarios associated with the immune profile are emerging such as association of multiple small disseminated liver metastases found in immune ‘cold’ tumours. The clinical presentation of CRC, together with mismatch repair status, immune cell quantification, and molecular features such as tumour mutational burden, may help delineate appropriate and personalized use of immunotherapy and the design of new trials.