The new tool is intended to help people make more informed decisions around treatment and to manage expectations following diagnosis.
The calculator also allows patients to update their mortality risk based on how long they have survived following a diagnosis.
The tool was developed by Professors Julia Hippisley-Cox and Carol Coupland from the University’s School of Medicine and ClinRisk Ltd. It used QResearch, a bank of anonymised patient data from approximately 1500 general practices across England through EMIS Health’s clinical computer systems linked to the national cancer registry.
Professor Hippisley-Cox said: “Current methods of estimating survival tend to be unreliable and sometimes patients can be given a fairly misleading and unnecessarily gloomy prognosis based only on the grade and stage of their cancer, only to find that in reality they live much longer than these crude predictions when other information is taken into account.
“The good news is that this new calculator which doctors and patients can access will offer a far more realistic estimate. We understand that not everyone will want to do this, of course, but some patients are very keen on this approach so it’s an individual choice.”
Current methods of predicting survival are based on simple averages based only on age or the grade and stage of the cancer in the wider population.
The new tool looks at a range of additional risk factors including the patient’s, smoking history, body mass index, family history, other illnesses and treatments such as aspirin or statins as well as other information including whether they have had surgery or treatments such as chemotherapy to deliver a far more personalised prognosis.
The team used information from more than 44,000 patients from 947 practices to develop separate equations for men and women aged between 15 and 99 years old when diagnosed with bowel cancer. The team will adapt the new web calculator to predict prognosis in other types of cancers in the future.