A cancer sufferer who was on the brink of death and riddled with 26 tumours has been “effectively cured” by radical therapy which triggers the body to heal itself.

The extraordinary case emerged as trials revealed a host of "unprecedented" advances using immunotherapy treatments at the world’s biggest cancer conference.

In one study, those treated with the combined therapies had a 61 per cent higher chance of not dying or the disease progressing, compared to those given standard treatment.

Five years ago Mike Chettle was diagnosed with bowel cancer, which spread to his liver, bones and abdomen, despite undergoing complex surgery and drug treatment.