Additional surgery for patients with mouth cancer significantly improves the chances of a cure, new research has found.

A major study, involving patients in Scotland, examined the outcome of removing lymph glands in the neck at the same time as removing the cancer in the mouth.

It found it almost halved the chances of disease recurring or the patient dying – even if scans showed no sign of cancer in the neck.

The findings, published in the British Journal of Cancer, have provided “solid” evidence for a major medical dilemma over how best to treat mouth cancer and could help save around 21,000 lives a year worldwide.

Charity Cancer Research UK and research foundation Saving Faces, which funded the study, say it was only possible due to a major collaboration across the UK involving 68 oral and maxillofacial surgeons and 614 patients.

The participants included consultant oral and maxillofacial surgeon Joseph McManners of Forth Valley Royal Hospital.

He said: “Mouth cancer is often neglected when it comes to research into finding better ways of treating it, however it is very important as the results of the disease or its treatment can dramatically affect the patient’s appearance and their ability to eat or speak.

“We now have clarity of an issue which has vexed surgeons for more than 20 years about how best to treat patients with small cancers who may have tiny undetectable deposits in their neck glands.

“Results show that removing the lymph glands at the same time as the mouth tumour almost halves the chances of the cancer recurring or the patient dying.”

Mouth cancer is the eleventh most common cancer in the UK, with cases increasing by 30% in the past decade.