The software, which automatically alerts GPs when symptoms suggest a risk of cancer, is being tested by GP practices in England and Wales and could be rolled out to all practice computer systems.
GPs involved in the project said it could save lives by identifying cancer earlier.
The Electronic Cancer Decision Support (eCDS) program scans information entered into the patient record during a consultation and matches symptoms to known risk factors such as smoking status.
It can automatically alert GPs when it detects a combination of symptoms known to be associated with cancer, and can help the GP decide whether further investigation is needed.
The tool can estimate the risk of oesophago-gastric, lung, colorectal, pancreatic and ovarian cancers.
Findings from a study of the new tool were presented at the National Cancer Research Institute’s conference on Tuesday.
The tool is based on work by academic GP Professor Julia Hippsley-Cox, who developed the QCancer risk calculator, and Exeter GP Professor Willie Hamilton’s risk assessment tool.
Professor Hamilton said the program would be used alongside patient notes.
He said: ‘What’s really useful is if, for example, a patient comes to see me with one symptom such as nausea or sickness. Then three weeks later they come back and say they’ve had trouble swallowing.
'The computer will automatically ping up with an alert to say their risk of oesophageal cancer is over 7%, which will alert me to refer the patient for tests.’
The tool was developed by Macmillan Cancer Support with funding from the DH.
Dr Rosie Loftus, lead GP adviser at Macmillan Cancer Support, said: ‘When you’ve only got around 10 minutes with each patient, it’s vital that you ask the right questions and are able to quickly calculate someone’s risk in order to facilitate an early referral.
'Macmillan hopes that this tool will support GPs to identify the symptoms of cancer and help to improve cancer survival rates.'