Research presented at the world’s biggest cancer conference in Chicago found that patients who told their doctors of their symptoms via an app or telephone helpline lived far longer than those who did not.
Leeds University is running a similar study using the same tool.
Experts think part of the reason is that people who receive help in managing their symptoms are far more likely to stick with chemotherapy or remain well enough for further treatment.
The new research, presented at the American Society of Clinical Oncology conference (ASCO), saw 766 patients with advanced cancer split into two groups.
Both groups were evenly matched for cancer type and treatment. Those in the app group were asked to record their symptoms in real time, such as whether they were in pain, had nausea or diarrhoea.
Clinicians offered help to those with worsening or severe symptoms, such as by giving more pain medication or anti-sickness drugs.
The results showed that patients in the app group lived five months longer on average than those receiving usual care.
Ethan Basch, professor of medicine at the Lineberger Comprehensive Cancer Centre of the University of North Carolina, said despite best efforts, doctors tended to miss half of symptoms in their patients.
He said: “Between visits people are often reluctant to pick up the phone. People want to please their doctors. We as doctors want to believe our patients are doing wonderfully well. There is a collusion, a shared denial, of the difficulties people are having. This causes people to miss problems until they become really severe.”