AI could spare bowel cancer patients from unneeded treatment
Anguraj Sadanandam of the Institute of Cancer Research, who co-led the research.
AI algorithms that can identify which patients are most likely to benefit from a drug recently backed for NHS use as a colorectal cancer (CRC) therapy have been developed by scientists in the UK and Ireland.
The PhenMap tool, developed by scientists at London's Institute of Cancer Research (ICR) and the RCSI University of Medicine and Health Sciences in Dublin, could be used to guide treatment with VEGF inhibitor bevacizumab, which had its recommended NHS indications extended last December to include previously untreated metastatic CRC patients undergoing chemotherapy.
The availability of biosimilars of bevacizumab has allowed its use for CRC by the NHS for the first time, but it only works for a small group of patients and carries the risk of serious side effects, including high blood pressure, gastrointestinal problems, and blood clots.
PhenMap has been deployed to analyse the genetic make-up of CRC tumours and other clinical and demographic data from 117 CRC patients, creating a machine learning algorithm that scores patients according to their likelihood of deriving a benefit from bevacizumab added to chemo. Another AI tool then generated a score to indicate the risk of dying after treatment with the combination.
One of the patterns identified by the AI was that patients with a mutation in the BRAF gene were all in the high-risk group and had poor outcomes, with a significantly higher risk of death. They have published their findings in a paper in the Nature journal Scientific Reports.
The next stage for the researchers will be to validate the AIs using a wider selection of patient samples, and also to see if similar predictive patterns can be found in other forms of cancer. The hope is that identifying patients most likely to benefit from treatment will improve clinical outcomes and save the NHS money that can be spent on other aspects of care.
"Once bowel cancer spreads to other parts of the body, there are very few treatment options available for patients. It is therefore positive that patients can now access the targeted drug bevacizumab on the NHS," said Anguraj Sadanandam, a professor in stratification and precision medicine at ICR, who co-led the study with RCSI's Annette Byrne.
"However, we know that the majority of patients won't benefit from the drug, meaning thousands of people in England could be facing unpleasant side effects unnecessarily. Until now, we haven't been able to identify these patients."
Around 35,000 people are diagnosed with CRC in England each year, and nearly 10,000 of those will have metastatic disease. Of these, roughly 7,000 are eligible for bevacizumab treatment, according to NICE.
Earlier this year, NHS England also said it would lower the threshold at which home-screening kits for bowel cancer will trigger a referral for further testing, estimating that would lead to 35% more screening colonoscopies each year.
