A study on lung cancer patients found that activating the immune system can prompt tumours into spreading friendly T-cells around the body, significantly reducing the chance of cancer returning after surgery.

Scientists have hailed the new approach, called "cancer interception", a "game-changer" potentially capable of stopping the disease in its tracks.

Teams are now setting out to trial the method on patients with blood, colon and ovarian cancers in what could be the start of a fundamental shift in treatment of the disease.

Oncologists in the US at Johns Hopkins University and the Memorial Sloan Kettering Cancer Centre administered the immunotherapy drug nivolumab over several weeks to 21 patients with non-small-cell lung cancer prior to surgery.

They found the strategy was not only safe, but that 45pc of the patients responded so well there was little evidence of the cancer remaining upon follow-up examinations.

Overall, recurrence-free survival at 18 months was 73pc.

This is compared to a roughly 50pc current clinical average.

The team believe the key to the success are the T-cells circulating through the patients' bodies after surgery which attack errant tumour cells and prevent new metastases.

They said the nivolumab effectively converted the lung tumours into an "auto-vaccine", pumping the cancer-killing cells around the body.

"That T-cells, activated by immunotherapy prior to surgery, can intercept rogue tumour cells throughout the body after the patient's operation and prevent the cancer from recurring may be a game-changer," said Dr Sung Poblete, president of Stand Up To Cancer, which funded the research.

"This notion of 'cancer interception' has the potential to stop cancer in its tracks. We are hopeful this breakthrough, and the follow-up clinical studies already under way, will translate into a new standard of care."

Traditionally, chemotherapy or chemoradiotherapy has been given to lung cancer patients to shrink a large, non-metastasised tumour. Immunotherapeutic agents have then been administered after surgery, but with limited results.

Alison Cook, director of policy for the British Lung Foundation, said: "This research is so full of hope. Treatment tomorrow is going to look very different - more lives will be saved."