Most patients with mouth, head or neck cancer present for treatment when the disease is already at an advanced stage, significantly reducing their chances of survival or a better recovery, a leading professor has warned.

According to Prof June Nunn, dean of the Dublin Dental Hospital, there are 400 new cases of these cancers diagnosed every year in Ireland and three people die every week from them - more deaths than from skin melanoma, Hodgkin's lymphoma or cervical cancer. Despite this, public awareness remains low.

Prof Nunn made her comments at the launch of Mouth, Head and Neck Cancer Awareness Day, which takes place this Wednesday (September 29).

On that day, anyone who is concerned about an ulcer or sore in their mouth can visit the Dublin Dental Hospital in Lincoln Place, Dublin 2, or the Cork University Dental Hospital on the campus of Cork University Hospital, for a free, painless mouth examination. Information on these cancers will also be available.

The awareness day has been organised by new support group MHNC (Mouth, Head and Neck Cancer), which is made up of cancer survivors, healthcare professionals and health promoters. The group is urging anyone with ongoing concerns to contact their GP or dentist.

The awareness day is being supported by the Dublin and Cork dental hospitals, as well as by Peter Sheridan, writer, director and throat cancer survivor and the family of Ronnie Drew, who lost his battle with throat cancer in 2008.

According to MHNC, mouth, head and neck cancer is the sixth most common cancer worldwide, with over 500,000 cases each year. These cancers are largely preventable as the two major risk factors are consumption of tobacco and alcohol.

Many mouth cancers could be detected at an early stage by a simple, painless screening examination, which takes less than two minutes. This is an important part of a routine dental check-up.

Early diagnosis and treatment can result in five-year survival rates of over 80%, compared to rates of 10-35% for advanced cancer.