Symptoms of tongue cancer include

• Ulcers in the mouth that do not heal,
• White or red patches in the mouth that cannot be scraped off,
• Lumps on the tongue,
• Swelling in the mouth and
• Pain when chewing or swallowing food

Ulcers that commonly come about when you accidentally bite your lip or tongue when chewing or talking should resolve within one to two weeks.

However, if the ulcer lasts more than two weeks, has irregular edges or hard nodules, or is growing quickly, it may be worrying.

Another way to differentiate between the common ulcer and one you should be worried about is the absence of pain. 

Most non-cancerous ulcers are painful due to inflammation. However, cancerous ulcers may not be painful at the beginning, making them more suspicious.

But not all tongue cancers start with an ulcer. Some notice a lump on the side of the neck that grows over time and becomes painful.

Previously, most sufferers were men, with the ratio being three male cases to one female. Now, the incidence is equal between the genders.

This trend is seen in other developed countries, but what is puzzling doctors here is that these female patients do not have the same triggers as before.

In the past, a typical tongue cancer patient was an elderly man who had been smoking and drinking his whole life. Smoking is a known cause of tongue cancer, along with sexually transmitted diseases (STDs) such as the human papillomavirus (HPV).

Today’s female patients do not have HPV or other STDs. They do not smoke, drink, or chew betel nut or tobacco. Nor are they associated with recently suspected causes – poor dentition (sharp teeth or badly fitted dentures) or the long-term consumption of immunosuppressants following treatment for kidney cancer, leukaemia or lymphoma.

NCCS’ clinician scientists embarked on a complex study to get to the bottom of the mystery.

Principal investigator Prof Gopal said they have ruled out HPV as a cause.

“In tongue cancer, the first thing we look for is HPV, but their tests proved negative. I confirmed this finding with a group in the United States engaged in a similar study. We also looked for genes the tumour might express, but there weren’t any clear-cut answers.”

Undeterred, they moved on to genome sequencing − at press time they had sequenced 18 samples, and were decoding the tumour’s genetic information and analysing the data they had collected.

“Some promising genetic markers have come up, and we’re trying to validate this. If we find specific genes such as enzymes causing the cancer, and if they can be targeted, that will be very promising. It’ll not just tell us what’s causing the cancer, but open up the possibility of creating an inhibiting drug,” said Dr Gopal.​