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Be on the lookout for oral cancer

From 2005 to 2015, the University of Toronto’s Oral Pathology Service (TOPS) diagnosed 828 cases of oral cancer from 63,483 biopsy specimens. By 2015, TOPS also detected more than three times the number of cases of oral epithelial dysplasia from these same biopsies, compared with 2005. This represents a major achievement in the early diagnosis of pre-malignant lesions.

The number of oral cancer cases diagnosed at TOPS between 2005 and 2015 represented an 84 per cent increase. This was significantly higher than the 36 percent overall increase in oral cancer cases detected by Cancer Care Ontario during the same period.

However, oral cancer survival rates have remained unchanged for the past several decades. Depending on the tumour stage at diagnosis, the five-year cure rate can range from 30 to 80 per cent, and still averages only 50 percent.

One main reason for this: oral cancer is often first discovered when it is already at a late stage of development.1

The TOPS study results were reported in the June 2019 issue of the Journal of the American Dental Association2 (read the report). The authors suggest that mandatory continuing education programs and an overall increased awareness are possible causes for these improved results.

How dentists can help

To continue to raise the survival rates for patients suffering from oral cancer, dentists have a duty to be on the lookout for the following signs, symptoms and suspicious lesions when conducting oral examinations:

  1. Ulcers - that present with a red centre surrounded by raised, firm rolled edges or with asymmetrical, ragged or irregular margins

  2. White patches – that present with asymmetrical, irregular borders and cannot be explained by the usual causes such as traumatic cheek biting or chronic irritation from sharp edges of teeth or prostheses

  3. Lumps – that are firm, noticeable and can be easily palpated

Diagnosis

If in your screening you spot a suspicious lesion, the first step is diagnosis. This means conducting a thorough visual and tactile soft-tissue examination of the:

  • lips
  • inner cheeks
  • palate
  • throat
  • gingiva
  • tongue (ventral, dorsal and lateral surfaces)
  • floor of the mouth
  • adjacent extra-oral surfaces of the lips, nose, cheeks and neck.

This examination can be accomplished in roughly 90 seconds.3

Key questions must be asked during the examination. Depending on your patient’s answers, the appropriate action must be taken to help ensure a proper resolution. This is particularly important if the patient is male, over the age of 60 and has a history of smoking and alcohol use.

Here are some examples of questions, answers and actions:

Question Answer Action 
How long have you been aware of this lesion inside your mouth?










Just noticed it last week.    








Re-evaluate in two to three weeks. Document and observe.







It's been there at least a month, maybe longer. Biopsy
Does it hurt? Does it hurt when you swallow? Does it seem to be getting bigger? Have you ever had this before?

Yes - it's a bit sore and seems to be enlarging. Bleeds sometimes. First time I've ever had this. 

Biopsy



Battling oral cancer requires training and developing skills in biopsy technique, as well as the ability to communicate the diagnosis effectively. If you are worried about fulfilling your professional duty without creating unnecessary anxiety, it’s best to be straightforward when speaking with your patients.

Consider this sample response when a patient asks why you want to take a biopsy:

“I’m concerned about this lesion. You mentioned it’s been present for at least a month, and seems to be getting bigger. To diagnose it properly I have to take a small sample of the tissue so it can be examined under the microscope.”

Consider this sample response when discussing positive biopsy results:

“The results indicate the presence of cancer cells in the tissue sample. In this situation, the next step is to refer you to an oncologist to discuss treatment.”

Myths and Facts about Risk Factors for Oral Cancer 4

Myth  Fact
Oral cancer occurs mainly in elderly individuals.


Males over 60 remain the highest risk group, but about six percent of cases occur in patients under 40.

Oral cancer occurs mainly in heavy smokers and drinkers.

One-quarter of oral cancer cases occur in non-smokers and non-drinkers. 

Oral cancer risk is highest among cigarette smokers. 




Risk is related to the amount and duration of tobacco consumed, regardless whether the source is cigarettes, cigars, pipes, smokeless, chew or betel quids. Oral cancer risk is reduced following cessation of smoking and alcohol intake. 
Infection with the human papilloma virus (HPV) confers a protective effect on developing oral cancer. 


HPV-positive patients, particularly the HPV-16 and HPV-18 sub-types, are at greater risk for oral cancer.  


Patients receiving immunosuppressing drugs following transplant surgery are unlikely to develop oral cancer.


Immunosuppressed and/or transplant patients show an increased oral cancer risk, which increases with the time post-transplant. 


Summary

The TOPS study results are encouraging. Diagnosing even one case of oral cancer may have life-altering benefits for a patient. Given the persistently low five-year cure rates, staying on the lookout for oral cancer is within the scope of every dental professional’s responsibility.

Resources

For more information on diagnosing oral cancer, please consult the references below.

  1. Oral Cancer Foundation
  2. JADA 2019 June, 150(6):531–539
  3. Dispatch 2002:16, April/May
  4. Laronde, DM. et al. 2008 April
  5. Brown, V. HPV 101: What Dentists Should Know. PEAK: 2014 Aug/Sept