Dr Bishal Gyawali speaks to ecancer about the placebo effect in oncology and the consequences of skipping cancer treatment. He discusses the statistical data and the scientific reasoning behind patients whose tumours shrink without targeted therapy or chemotherapy.

A study looking at the placebo arm of trials found that 2% of patients show some response to placebo treatment which he finds intriguing.

Dr Gyawali notes that after analysing the data available he can say that the chances of the entire cancer melting away with no treatment are zero. Partial response to placebo monotherapy is 1% to 2%, which is not very promising.

This data can help people make an informed decision about whether to choose chemotherapy for themselves or not.

Dr Gyawali highlights that in the future, patients' molecular and genetic profiles who show a response to placebo should be investigated.

He also states that drugs should be approved based on complete response rate rather than overall response rates because even a placebo treatment shows some overall response rate.