There's been a dramatic increase in the incidence of rare tongue cancer in people under 45, particularly in young, non-smoking women, new research has found.

There's been an alarming rise in the number of young people, particularly women, being diagnosed with tongue cancer, a disease predominantly found in older men with a history of smoking or heavy drinking.

Researchers from the cancer hospital Chris O'Brien Lifehouse at Sydney's Royal Prince Alfred Hospital, in collaboration with local and overseas colleagues, have published a new study in the journal Oral Oncology.

It shows a significant increase in the incidence of tongue cancer in people aged under 45 while the incidence in young women has soared by a staggering 385 per cent in 32 years.

"Tongue cancer is traditionally a disease found in older men with a history of smoking or heavy drinking," Associate Professor Carsten Palme, Director of the Head and Neck Cancer Service at Chris O'Brien Lifehouse, said on Monday.

"The data confirms a worrying global trend that we have been observing for some time in head and neck cancer."

Despite a steady decrease in the number of people who smoke in the past decade, the results show an increase in young people without identifiable risk factors being diagnosed with oral cancer.

In particular, the number of women under 45 being diagnosed with tongue cancer is rising faster than for women over 45 and men.

Tongue cancer is a rare disease involving highly complex treatment, which can involve removal of part of the tongue and jaw.

It can affect speech and swallowing, cause facial disfigurement and result in a lifelong dependence on feeding tubes.

The huge increase is of particular concern to the nation's dentists, who are in a prime position to detect early changes in the mouth.

"Early detection is critical to achieving a good outcome for these young patients," said Associate Professor Palme.

"We are now looking to identify the potential cause of the disease in these young, non-smokers to not only better treat the cancer but also put appropriate prevention measures in place."

The study was based on data from 11,682 patients with tongue cancer from Australia and Singapore.