Colorectal cancer is the third most common cancer globally, with nearly 2 million cases yearly. About 75% are detected in the early stages and treated with surgery and chemotherapy. Scientists are searching for markers to predict risk and new treatments. In this study, researchers looked at markers in colorectal cancers from large clinical trials to understand their predictive significance.
In this study published in The Lancet Oncology, researchers looked at the cases from the SCOT trial and the QUASAR 2 trial, both of which were led or supported by the University of Oxford. The main goal of the study was to see whether tumour infiltration by immune cells predicted whether colorectal cancer recurred after initial treatment. The researchers considered the time from when patients were chosen for the study until they experienced a relapse, along with the cases where there was no recurrence or event of death.
By looking at multiple immune cell types in more than 3,000 tumours using an AI-based method, the researchers found as expected, tumour infiltration by cytotoxic (CD8) T cells was associated with better outcome. Unexpectedly, they also found that tumour infiltration by regulatory (FoxP3) T cells also predicted better outcome, a result which contrasting with other cancers where these cells confer worse prognosis. Quantification of both cell types improved on the value of either alone for prediction of relapse and may help personalise treatment for patients in the future.
The co-lead author of the study Dr David N Church from the Centre for Human Genetics at NDM, said: ‘Our study confirms that infiltration of bowel cancer with FoxP3 immune cells is associated with better outcomes – a finding which contrasts with other cancer types. We are now focused on understanding why this is the case, and potentially targeting these cells for treatment’