The QCancer tool, developed by the University of Nottingham, red flags potentially serious cases of certain symptoms and risk factors for gastro-oesophageal and lung cancer in patients.
Research published in the British Journal of General Practice showed that the tenth of patients predicted by the tool as most at risk of developing the diseases went on to account for 77% of these cancers.
Lead researcher Professor Julia Hippisley-Cox of the University of Nottingham said: 'Earlier diagnosis of cancer is a major challenge and we hope this new research will help doctors identify patients for earlier referral and investigation.'
GPs can access the online tools at www.qcancer.org.
