BOLTON-born BBC Radio host Mark Radcliffe announced to listeners that he has cancerous tongue and lymph nodes and will not be on air for a while.

But what is mouth, or oral, cancer and how does it develop?

This kind of cancer is the sixth most common in the world although much less common in the UK with around 6,800 people diagnosed annually. It involves a tumour developing in the lining of the mouth. This may occur on the surface of the tongue, the insides of the cheeks, the roof of the mouth (palate) or the lips or gums.

Tumours can also develop in the glands that produce saliva, the tonsils at the back of the mouth and in the pharynx – the part of the throat connecting the mouth to the windpipe.

In the case of 60 year-old Mark, it appears to have developed on the tongue and nearby. However, he told listeners that it had “all been caught very early and so everything should be fine.”

Early diagnosis in this, as in all cancers, makes a difference. The symptoms to watch for include sore mouth ulcers that refuse to heal within several weeks and unexplained persistent lumps in the mouth or neck that don’t go away.

Other indicators may be unexplained looseness of teeth or sockets that do not heal after extractions, white or red patches on the lining of the mouth or tongue and changes in speech like a lisp. Unexplained, persistent numbness or an odd feeling on the lip or tongue may also be an indicator.

It’s recommended to see your GP or dentist if any of these symptoms occur, especially if you drink or smoke heavily.

The sexually-transmitted Human Papilloma Virus (HPV) is thought to be associated with the majority of mouth cancer cases in younger people.

Mouth cancer itself is categorised by the types of cell the cancer (carcinoma) starts in. Squamous cell carcinoma is the most common and accounts for nine out of 10 cases; squamous cells are found around the body.

Most cases of mouth cancer occur in adults aged 50 to 74 with only one in eight cases younger than 50. There are three main treatment options. Surgery can remove the cancerous cells along with a tiny bit of the surrounding normal tissue or cells to ensure it is completely removed.

Radiotherapy, using high-energy x-rays, is used to kill cancerous cells and chemotherapy, with powerful medications, is also used to kill them. The treatments may be used in combination.

As well as trying to cure the cancer, treatment focuses on important functions of the mouth like breathing, speaking and eating and high priority is given to maintaining the appearance of the mouth.

The most effective ways of preventing mouth cancer are not smoking, not drinking more than the recommended weekly limits for alcohol and eating a healthy, Mediterranean-type diet with plenty of fresh vegetables – especially tomatoes – citrus fruits, olive oil and fish.

ENT consultant Mr Simon Hargreaves and colleagues see many cases of head and neck cancer at the Royal Bolton Hospital.

“Even though we are beginning to see less smoking-related cancers, there is still an increase in head and neck cancers including mouth cancer,” he explained. “We believe the latter is due to the HPV virus and as a result there are now more younger patients.”

He added that, while girls already had the HPV vaccine, this was the reason doctors campaigned for boys to have it, too.

Mr Hargreaves also pointed out that the effects of giving up smoking could still cause cancers “for decades”, although it was still worth quitting.