AI Bowel Cancer Test Determines Need for Chemotherapy in Patients: Study

A study published in the Journal of Clinical Oncology reveals that a new artificial intelligence (AI) test can assess the risk of bowel cancer recurrence and potentially help patients avoid chemotherapy. Led by researchers at the University of Leeds, the test uses an AI algorithm to accurately evaluate the presence of CD3 immune cells in early-stage bowel cancer tumours. Bowel cancer, also known as colorectal cancer, affects the large bowel, including the colon and rectum, and was diagnosed in 1.9 million cases globally in 2020.

In the study, the CD3 Score test reliably showed which stage II cancers were most likely to recur within five years of surgery – and this could be used by clinicians to decide which patients may need further treatment such as chemotherapy.

Current methods for deciding which patients with early-stage bowel cancer need chemotherapy and which do not are unreliable. Many people receive chemotherapy when they don’t need it, and unfortunately some of the people who are not offered chemotherapy go on to experience cancer recurrence.

Previous studies have shown that bowel and rectal tumours with higher numbers of CD3 immune cells are less likely to recur after being removed by surgery. This is because CD3 cells can attack the cancer, helping the body tackle the disease.

They examined tissue from 868 bowel tumours at stage II and III to establish the numbers of CD3 cells within the tumours. The AI algorithm developed by the team calculated a ‘CD3 Score’ based on the number of CD3 cells in different areas of the tumour. High risk scores had lower numbers of immune cells, while low risk scores showed increased numbers of immune cells.

It is concluded that recurrence rates were reduced in both groups when patients underwent chemotherapy, but the study also showed that patients with lower numbers of immune cells were the most likely to benefit from chemotherapy.

References: Böckelman C, Engelmann BE, Kaprio T, et al: Risk of recurrence in patients with colon cancer stage II and III: A systematic review and meta-analysis of recent literature. Acta Oncol 54:5-16, 2015