Scoping out oral cancer
For those of you living in Vancouver, you probably have seen that London Drugs has started a
program where they are offering free oral cancer screenings (unfortunately they are all booked already). This is a great service to the community because it has really helped raise the awareness of oral cancer.
Read here: London Drugs Free Cancer Screening
Not many people are aware of how prevalent oral cancer is. Did you know that every year in BC, 3 times as many people die of oral cancer, than from cervical and testicular cancer combined? I had never even heard of oral cancer until I became a dental student, but I sure knew about other, rarer, cancers. After a few short weeks of this advertising program, I have already had many people ask me about oral cancer.
So yes, raising awareness of oral cancer is a great thing!
Unfortunately, this free screening program, while being great for raising awareness, has placed a heavy emphasis on the promotion of a particular screening tool, called the VELscope®. What exactly is this fancy device?
Let us talk about the VELscope®.
What is the VELscope®?
The VELscope® is a home-grown oral cancer screening tool; it has been developed, and is still based out of BC (http://www.velscope.com/). It works on the concept that inflamed, unhealthy tissues have a different fluorescence than healthy, normal tissues. The dentist shines a fluorescent light at the patient's mouth, and the tissues reflect the light in a particular manner if they are healthy or if they are inflamed. Non-invasive and pain free.
Photos Courtesy: Dr. Yoko Tsukada, Oral Medicine and Oral Pathology Specialist
Does it detect cancer?
One of the challenges with using the VELscope® is that it only helps detect abnormal tissues; it does not definitively allow for a cancer diagnosis.
Much of the reasearch on VELscope® has been on patients who already have a confirmed cancerous lesion. It can be very effective at determining the extent, or margins, of a cancerous lesion that has already been diagnosed. This is helpful in the treatment and monitoring of existing oral cancer.
It cannot, however, readily distinguish between oral cancer and
benign lesions, such as the "hyperkeratosis" on the photo to the right, resulting in false-positive results (looks like cancer on the scope, but it actually is not).The VELscope® can therefore only point someone towards a suspicious area, but further screening is required to confirm a diagnosis of cancer.
Read:
The College of Dental Surgeons of BC has published guidelines for oral cancer screening, and it lists the use of fluorescent light devices as "optional". Tests such as these are not necessarily good screening tools because of the amount of "false-positives". We can talk about the efficacy of screening tests based on specificity and sensitivity another day.....but that is pretty nerdy.
How do dentists and physicians actually diagnose cancer?
Health professionals have many tools that in their armamentarium that can aide them in the detection of oral cancer and precancerous lesions, starting with a proper history and clinical examination, and then including adjuctive tests such as fluorescence or dyes.
Once a suspicious area is identified, the only way to truly diagnose whether it is cancerous or not is.....are your ready for it fellow Columbia grads?.......a BIIIIIIOOOOOPSY.
A biopsy is a simple procedure where a piece of the suspicious tissue is cut out for further evaluation. It is then sent to a trained and certified pathologist for him/her to look at the sample under a microscope. This is still the best, and the only definitive way, to truly DIAGNOSE oral cancer, and to differentiate it from potentially harmless conditions.
Considering that a piece of tissue needs to be snipped out to confirm a diagnosis, do you think that using a tool with a high rate of false positives is a good screening tool? Obviously an oral cancer screening is more than just shining a light at someones tongue, but the user has to be well versed in how to use the machine so he/she is not sending every bump in the mouth for biopsy.
What do I do if I find a funny lump or bump in my mouth?
First of all, don't panic. It is normal to have a sore spot in your mouth from time to time. It could be from a nacho incident, or a hot pizza, or a popcorn kernel stuck under the gums. Ok...I must improve my diet if those are the examples I am bringin up......
But if you see something strange that hasn't gone away in a couple of weeks, book a visit to the dentist or physician. Common areas for oral cancer are: the side of the tongue, the lip, the tonsils and the floor of the mouth. Obviously it can pop up anywhere but those are the common spots.
Every dentist should be performing a comprehensive examination of the oral mucosa, tongue and lips at an initial examination, and at every recall exam. A thorough history is imperative as well. Don't fudge the facts on smoking and drinking on your history form. You may be a little surprised if your dentist asks you about unprotected oral sex, or number of sex partners on these health forms but.....
HPV is increasingly being correlated to oral cancer!
The more we are learning about the genetics of these cancerous tumours, we are seeing that as much as 30% of new oral cancer diagnoses are associated with HPV. Its exact role in the carcinogenesis is still debatable, but we know there is a correlation.
Read: Oral Cancer and HPV
Dentists are having to ask questions that they never routinely asked before.
When do I need a biopsy?
Usually there is a pretty straight forward reason as to why there is a change in the tissues (pizza burn, for example), and there is no reason to biopsy. In my office, I am a little more cautious when it comes to sending someone for biopsies, especially if they present with risk factors. If I find a lesion that looks suspicious, I document it well, and then I point it out to the patient so they can monitor it at home. I bring them back a couple of weeks later to follow up and to and see if it has healed. If not, I send them to an oral pathologist to get it evaluated further. More often than not it is nothing troublesome, but it is better to know for sure.
If you have any questions about oral cancer, visit your dentist. Unfortunately, we are seeing a change in the demographics of this cancer. It is no longer a cancer of old, smoking and drinking men; more and more people are getting diagnosed with oral cancer at a younger age. Scary! Early detection is key, so go get checked on a regular basis.
For more information visit:
Thanks for reading!!!!
Dr. Dave
drdave@alfaropros.com
Photo Credits:
1. Wikimedia Commons (public domain)
2&3. Dr. Yoko Tsukada, OMOP FRCD(C)
4. NIH
5.http://commons.wikimedia.org/wiki/File:Oral_cancer_%281%29_squamous_cell_carcinoma_histopathology.jpg
