# Immunoscore

Source: https://onco.cc/terms/immunoscore/  
OnCo record `immunoscore` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The Immunoscore counts the immune cells inside a bowel tumour and at its invading edge and turns the density into a single score. People with a high score relapse far less often than people with a low one, whatever their stage, and the score adds information the stage does not.

## Summary

How it is measured. Paraffin sections of the tumour and its invasive margin are stained for CD3 and CD8, the densities are quantified by digital pathology, and the score is the mean of four density percentiles, reported as low, intermediate or high.

The validation. An international consortium of 14 centres in 13 countries, led by the Society for Immunotherapy of Cancer, assessed the assay in stage I to III colon cancer. Samples from 3,539 patients were processed and 2,681 passed quality control, split into training (700), internal validation (636) and external validation (1,345) sets. Reproducibility between observers and centres was high (correlation 0.97). In the training set, recurrence at five years occurred in 8 percent of patients with a high score, 19 percent with an intermediate score and 32 percent with a low score (hazard ratio 0.20 for high against low), and the finding held in both validation sets. The association with time to recurrence was independent of age, sex, T stage, N stage, microsatellite instability and the existing prognostic factors, and in the 1,434 patients with stage II disease the difference remained significant (hazard ratio 0.33). The Immunoscore made the largest relative contribution to recurrence risk of any clinical parameter, including the stage itself (Pages 2018).

What it is for. The clinical question it speaks to is which stage II patient needs adjuvant chemotherapy, where stage alone decides badly. It has not displaced stage or circulating tumour DNA in routine practice, and it is measured in research and in some European centres rather than reported as standard. The immune biology it measures is the same one that makes mismatch repair-deficient tumours respond to checkpoint inhibitors.

## Fields

- Kind: Term
- Last checked: 2026-09-24
- Also known as: consensus Immunoscore; immune score; CD3 and CD8 density score; TNM-Immune classification
- Tags: gi; colorectal

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Immunoscore
- Pages, Lancet 2018: international validation of the consensus Immunoscore for the classification of colon cancer (2,681 patients): https://doi.org/10.1016/s0140-6736(18)30789-x
- Guinney, Nat Med 2015: the consensus molecular subtypes of colorectal cancer: https://doi.org/10.1038/nm.3967

## Connected records

- cancers: [Colon cancer (adenocarcinoma of the colon)](https://onco.cc/cancers/colon-cancer/), [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Mismatch-repair deficient (MSI-high) colorectal cancer](https://onco.cc/cancers/msi-high-colorectal/), [Rectal cancer](https://onco.cc/cancers/rectal-cancer/)
- technologies: [Histopathology & immunohistochemistry](https://onco.cc/technologies/histopathology-ihc/), [Immune checkpoint inhibitors](https://onco.cc/technologies/checkpoint-inhibitor/)
- terms: [Circulating tumour DNA (ctDNA)](https://onco.cc/terms/ctdna/), [Consensus molecular subtypes (CMS1-4)](https://onco.cc/terms/cms-subtypes/), [Digital pathology and whole-slide images (WSI)](https://onco.cc/terms/digital-pathology-wsi/), [Microsatellite instability (MSI-H) / mismatch repair deficiency (dMMR)](https://onco.cc/terms/msi/), [Minimal / molecular residual disease (MRD)](https://onco.cc/terms/mrd/), [TNM staging](https://onco.cc/terms/tnm-staging/)

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