A new computer programme can alert family doctors when they need to send patients for cancer tests, researchers have said.
The software can determine a patient's risk of having certain types of cancer based on their symptoms, they said.
As well as knowing what risk a single symptom, such as a persistent cough, might carry, the computer program also automatically alerts GPs when it recognises a combination of symptoms.
For instance, if a patient visits their GP complaining of nausea and returns three weeks later with difficulty swallowing, the programme detects that the patient could be at risk of oesophageal cancer.
The software, called electronic Cancer Decision Support, also compares symptoms against other factors, such as whether the person smokes or is an ex-smoker.
The programme, presented at the National Cancer Research Institute (NCRI) Cancer Conference in Liverpool, can estimate cancer risk for oesophago-gastric, lung, colorectal, pancreatic and ovarian cancers, researchers said.
While the software is still in the testing phase of the trial the researchers hope that eventually it could be made available to all GPs.
"We hope that this new computer program will prove useful and effective in helping GPs make decisions about when to send their patients for further tests based on cancer risks," said Professor Willie Hamilton from the University of Exeter, and one of the researchers upon whose work the tool is based.
"Despite the fact that more than one in three of us will be diagnosed with cancer in our lifetime, cancer cases are still relatively unusual occurrences for GPs to encounter during their day-to-day practice.
"We've designed a system that doesn't replace their knowledge or training, but could be used alongside their notes to give extra information."
Dr Rosie Loftus, lead GP adviser at Macmillan Cancer Support - which led the work with part-funding from the Department of Health, said:
"GPs have a vital role to play in ensuring that cancer is diagnosed at an early stage to give people the best possible chance of survival.
"When you've only got around ten 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."
Dr Harpal Kumar, chief executive of Cancer Research UK and chair of the NCRI, said: "Diagnosing cancer early is crucial to surviving this devastating disease.
"GPs are on the frontline when it comes to assessing possible cancer cases so it's essential that they have all the information they need to make effective referrals."