• 10/23/2007
  • Vancouver, British Columbia, Canada
  • staff
  • Canadian Press (candianpress.google.com)

An increasing number of patients have a new decision to make when they go to the dentist, above and beyond choosing tooth whitening or the flavour of a fluoride rinse.

When patients visit the dental office of Dr. Mark Suyama in Vancouver, they’re asked if they’d like an oral cancer screening using the VELscope, a device invented at the B.C. Cancer Agency.

An estimated 500 Canadian dentists and about 1,500 in other parts of the world have purchased the $5,000 piece of equipment for their practices, according to John Pohl, a spokesman for LED Dental of White Rock, B.C., which has been selling the product since the middle of last year.

Suyama got his VELscope, which uses blue light aimed into the oral cavity, about three months ago. The healthy tissue glows as an apple-green colour, while a problem area that might indicate a pre-cancerous lesion shows up darker.

“It’s very easy. It’s just like using a flashlight almost – just like shining a flashlight in someone’s mouth,” Suyama said.

“We’re offering it to everybody, but we’re charging $45 and that’s not always covered by dental insurance. So some people are hesitant to spend the money.”

Calum MacAulay, a research scientist at the cancer agency, says the agency has been involved in the study and use of tissue autofluorescence for early cancer detection in other parts of the body.

“Three or four years ago I was listening to a colleague talk about the problems in oral cancer and thought it might be that what we’d done for the skin might be useful for them in the oral cavity,” he recalled of how the VELscope came to be.

“So I gave her one of our older versions that we’d used for the skin. She tried it, and it seemed to work quite well.”

The patent eventually ended up with LED, and the product, which received approvals from Health Canada and the U.S. Food and Drug Administration, is now manufactured in California.

An estimated 3,200 Canadians will be diagnosed with oral cancer this year, and an estimated 1,100 will die from it, according to the Canadian Cancer Society.

Smoking, alcohol use and HPV infection are considered to be some of the risk factors associated with the disease, MacAulay explained.

“The problem is most of the time it’s not detected until it’s actually late, full-blown cancer. Then it’s difficult to cure and it recurs quite a bit when it’s excised,” he said.

Although patients may not realize it’s happening, dentists and hygienists normally conduct visual exams and check for signs of oral cancer, and will refer patients to specialists if they have cause for concern.

But Pohl said a conventional oral cancer screening exam is limited to dangers that can be seen and felt.

“Many cancerous and pre-cancerous lesions are beneath the surface out of sight of the naked eye,” he said. “And that’s where VELscope comes along. VELscope can see well beneath the surface and identify cancerous and pre-cancerous lesions that might not be visible to the naked eye.”

The VELscope is considered to be an adjunctive device, not a diagnostic tool. The light goes through the epithelium into the underlying tissue.

“If it’s abnormal tissue, it will be dark or dark reddish-brown or orange, and that’s because what happens is as the tissue becomes more abnormal, it becomes thicker,” MacAulay said. “So that means the blue light has to go through more to get down to the stuff that actually fluoresces or glows.”

Using the VELscope can also help a surgeon determine how much tissue needs to be removed, he said. Typically surgeons have removed a one-centimetre margin around the cancer.

“Well, in using the VELscope, they found that essentially more than half of them had a VELscope-positive area that went more than a centimetre away from the lesion,” he said. “So essentially when they were leaving their one-centimetre margin, that necessarily wasn’t enough.”

The VELscope isn’t the only oral cancer discovery tool available to dentists. Zila Pharmaceuticals in Phoenix, Ariz., sells the ViziLite Plus system, which can also detect abnormalities in the oral cavity.

The patient rinses his or her mouth with a dilute acetic acid solution so that damaged tissue appears white when viewed under ViziLite’s diffuse low-energy wavelength light.

Brian Hill, a survivor of Stage 4 oral cancer and the founder of the Oral Cancer Foundation, welcomes the addition of both VELscope and ViziLite to the marketplace.

“As doctors have used more adjunctive devices, they’ve done more screening. The foundation thinks that this is really a great thing,” Hill, 59, said from Newport Beach, Calif., where the foundation is based.

“We hope that the reason that they’ve chosen to do this is because they’ve now gotten new tools that allow them to be more efficient at doing screenings.”

Pohl said prices charged by individual dentists start at about $25, and some are telling their patients it’s not optional.

The Canadian Dental Association hasn’t taken a formal position on use of the VELscope. Dr. David Zaparinuk, a member of the board of directors, doesn’t have one yet but thinks it’s something dentists will be bringing into their offices more routinely.

“There are many non-cancerous abnormalities in the mouth, even, say, a canker sore, that will produce a result with this machine, so it’s important that an experienced practitioner knows what they are or aren’t looking at,” he said from Victoria, where he has practised for 18 years.

“So is this machine definitive in itself? No, it’s not. So what the profession is working on determining now is where does it fit into the diagnostic spectrum and what is the appropriate usage of this type of a technology.”

Zaparinuk said the profession is working on an infrastructure to deal with emerging technologies.

“Things like, what do you bill for this? What do you bill it as?

“And hopefully, insurance carriers, third-party benefit carriers, will pick up that this is a valuable diagnostic tool and they will essentially reimburse people or cover the expense.”

MacAulay said training is needed for users so that false positives can be ruled out – tissue that might have been irritated by hot liquid or someone biting their cheek, for instance.

He said studies are taking place to find out how much training dentists need, whether retraining is needed, and how many at-risk people are caught using the VELscope versus regular oral cancer examinations without it.

MacAulay said the definitive clinical trial or randomized trial that shows it gives a significant benefit hasn’t been done.

“Right now, we’re at the ‘you could use it’ and we’re working towards the ‘you should use it.’ But you have to prove experimentally that you should use it – at least that’s the approach we’re taking,” he said.

Meanwhile, at Suyama’s office, about one person a day asks to have the screening done, mainly people who have been smokers and feel it’s worth it to spend the $45.

“Most of them have something that they’re a little bit concerned about, so they say, ‘Yeah, I want to have it checked out,”‘ Suyama said. “They’re usually grateful – most things don’t turn out to be cancer or anything to worry about. So they’re usually quite happy.

“So far, everyone’s been very lucky.”