Artificial intelligence that scans GP records to find hidden patterns is helping doctors find far more cases of cancer.
General practitioner practices using the “C the Signs” AI tool increased cancer detection rates from 58.7% to 66.0%. The tool analyses patients' medical records and compiles past medical history, test results, prescriptions, treatments and other personal characteristics that may indicate cancer risk, such as postcode, age and family history.
The tool also prompts GPs to ask patients if they have any new symptoms and will recommend tests or clinical pathways for patients to be referred if it detects patterns in the data that suggest an increased risk of certain types of cancer.
C the Signs is used in around 1,400 practices in England (around 15%) and was tested in 35 practices in the East of England in May 2021, covering 420,000 patients.
Result is, Journal of Clinical OncologyAccording to the study, cancer detection rates rose from 58.7% to 66.0% by March 31, 2022, but remained similar in clinics not using the system.
“You might need a scan or an ultrasound or even a visit to a specialist in clinic,” said Bea Bakshi, a GP who developed the system with her colleague Miles Paling.
Patients are tracked through the C the Signs system, which prompts doctors to look elsewhere for test results and referrals. “Our system has detected over 50 types of cancer,” Bakshi says. “The key is not just earlier diagnosis, but faster diagnosis.”
Bakshi and his colleagues also sought to validate the tool by evaluating 118,677 patients in a previous study, finding that 7,295 were diagnosed with cancer and 7,056 were correctly identified by the algorithm.
If the tool concluded that a patient was unlikely to have cancer, only 239 of the 8,453 people (about 2.8%) were confirmed to have cancer within six months. Bakshi developed the tool after encountering a patient in the hospital who died three weeks after being diagnosed with pancreatic cancer.
“That remained a problem area for me,” she said. “Why are there such delays in diagnosis for cancer patients?”
There are three cancer screening programmes in the UK – for bowel, breast and cervical cancer – but there are 200 types of cancer that may be asymptomatic or cause symptoms that can easily be confused with other diseases.
“Two-thirds of deaths are due to untestable cancers, or cancers that aren't tested for,” Bakshi says. “Patients visit their GP three to five times before they are aware they are at risk for cancer. GPs detect an average of eight cancers a year.”
GPs use National Institute for Health and Care Excellence guidelines to decide when to make a cancer referral.
“They're fairly comprehensive guidelines but not every GP will have them all memorised,” said GP Peter Holloway, chair of the East of England Cancer Coalition's primary care group and co-author of the study.
“We know that many cancers have vague symptoms, some of which are hard to define and don't necessarily correlate with our guidelines.”
Dr. Holloway saw a patient in his early 60s with diarrhea and lower abdominal pain. “These are very common symptoms, and it's not something I would refer you for as cancer,” he said. But the C the Signs tool suggested a stool test.
“The test came back positive, he was referred and it turned out he had colon cancer. It was diagnosed early and he was treated successfully,” Mr Holloway said. “He's doing well but if we had followed the strict guidelines he may not have been referred for several months.”
The NHS's long-term cancer plan for England aims to diagnose 75% of all cancers as stage 1 or stage 2 by 2028. The NHS is also investigating whether the Garelli blood test, which detects DNA from more than 50 types of tumours, could be effective. The trial began in September 2021 and has tested 140,000 people.
Holloway said decision support systems like C the Signs were a key part of cancer detection, along with improving patient awareness of the different symptoms of cancer and improving access to diagnostic technologies such as CT and MRI scanners.
Professor Peter Johnson, national clinical director for cancer for NHS England, said: “Despite increasing demand and pressure on services, record numbers of people are being tested and treated for cancer and we are now seeing increased rates of early cancer diagnosis, giving people a better chance of survival.”
“We know there is still much to do to help cancer patients get the treatment they need. Harnessing the latest technology is a key part of our efforts to reduce wait times and detect cancer earlier – for example, 'teledermatology' to diagnose skin cancer, community lung cancer screening vans and at-home testing for colorectal cancer.”
