July 1, 2014
by David Gane, DDS
It is estimated that there are 640,000 people diagnosed with oral cancer annually on a worldwide basis. In North America, oral and pharyngeal cancers will claim one person every hour of every day.
All too often, oral cancer is detected late, when the necessary interventions are profound and the prognosis pessimistic. It is essential to have patient-friendly clinical protocol for screening patients on a regular basis. LED Dental has developed the ‘See to Treat’ pathway for the discovery of oral cancer through specific channels, enabling earlier intervention treatment.
• Early discovery of lesions
• Testing for high-risk pre-cancers
• Enhanced accuracy for the excision of diseased tissues impacting reoccurrence
The ‘See to Treat’ pathway is intertwined with emotional and physical benefits to the patient, and is fundamental to the reduction of oral cancer treatment costs when they can be discovered and treated early.
TISSUE FLUORESCENCE VISUALIZATION
Traditional oral mucosal examination techniques rely on reflected light to visualize the oral cavity. VELscope Vx’s enhanced tissue fluorescence gives the Enhanced Oral Assessment System relevance regarding additional diagnostic value.
The basic premise of tissue fluorescence is that it allows clinicians to see cellular, structural, and/or metabolic activity changes in oral mucosal tissues by the observation of the oral tissue fluorescence response to light excitation. Changes in normal fluorescence patterns arise from a variety of causes, including:
• An increase in metabolic activity in the epithelium
• A breakdown of the fluorescent collagen cross-links in the connective tissue layer beneath the basement membrane
• An increase in tissue blood content, either from inflammation or angiogenesis (hemoglobin strongly absorbs fluorescence excitation [blue] and emission light [green])
• The presence of pigments (e.g., melanin or amalgam particles) which absorb light
As an adjunctive device, the VELscope Vx is effective in the visualization and discovery of a wide spectrum of oral trauma and disease, such as viral, fungal and bacterial infections, inflammation due to a variety of causes (including lichen planus and other lichenoid reactions), dysplasias, pre-cancerous lesions, cancers-in-situ, as well as squamous papillomas and salivary gland tumors.
THE NEW FACE OF ORAL CANCER
There is an emerging discussion to create public awareness and engage dental practitioners as the demographics associated with oral cancer shift. Historically the ‘at-risk’ group was the individual over 40 years of age who regularly used tobacco and/or alcohol. Today, according to the Oral Cancer Foundation, the fastest growing segment for oral cancer diagnosis is the young, healthy, under 40 demographic. New research confirms that the risk factors for oral cancer have been expanded to include two strains of the Human Papilloma Virus (HPV 16 and 18), in addition to tobacco use, frequent alcohol consumption, a compromised immune system and prior history of cancer.
A study released by the National Cancer Institute cites an astonishing increase of 225% between 1998 and 2004 for HPV-related oral cancers. Young, healthy individuals now make up the group that requires urgent attention through regular oral cancer screenings. In response, LED Dental has implemented a comprehensive training program and provides expert clinician support for dental professionals who are incorporating the VELscope Vx Enhanced Oral Assessment System into their practices.
EARLIER DISCOVERY MEANS ENHANCED TREATMENT OPTIONS AND BETTER PATIENT OUTCOMES
When discovered early, the treatment outcomes for patients with oral cancer are statistically favorable. However, oral cancer is rarely discovered during the early stages when the cellular level changes are essentially invisible to the naked eye. By the time most lesions are discovered, they are late stage, with many having metastasized, and thus requiring more invasive, and often disfiguring treatment. The high morbidity associated with oral cancer treatment can have severe emotional and financial consequences. Consequently, the five-year survival rate of oral cancer diminishes to approximately 50 percent for late-stage discoveries.
The VELscope Vx is an imaging modality which is extremely sensitive to tissue changes, and its use in everyday practice can provide timely information to dentists and hygienists to enable earlier detection of abnormal tissues and provide better outcomes for patients. In fact, when discovered early, the five-year survival rate for oral cancer patients is about 83 percent, significantly improved from the five-year survival rate of around 50 percent for late-stage discoveries.
TESTING FOR HIGH-RISK PRE-CANCERS
Until recently, a major barrier to oral cancer prevention has been the lack of validated risk predictors for oral mucosal premalignant lesions. If a technology could measure specific genetic markers that could successfully predict aggressive tumor growth, it would give clinicians the ability to distinguish between high-risk and low-risk oral pre-cancers at the point of lesion discovery.
A recently announced project by LED Medical and Genome British Columbia, “Development of an actionable molecular test for risk assessment of oral pre-cancers,” is designed to develop the first test to quantify the likelihood that an oral mucosal lesion will progress to cancer.
Soon, a non-invasive in-office test, based on a quantifiable genetic phenomenon known as “Loss of Heterozygosity,” or “LOH” will be available to patients who present with oral mucosal lesions.
The test results will either spare a patient unnecessary trauma and anxiety, or allow the clinician to fast track them through to urgent intervention and treatment. Early lesion discovery provides the key.
Introducing Cancer Prevention Protocols to the Patient
The best opportunities for early discovery of oral cancer occur when patients receive annual examinations that include:
• A comprehensive clinical oral exam consisting of palpation and visualization of the lymphatic nodes of the neck and face
• A visual and tactile inspection of the oral cavity using “white light”
• An examination of the oral cavity with an adjunctive tissue fluorescence device such as the VELscope Vx
The six-month hygiene appointment gives the clinician a periodic opportunity to reinforce the care philosophy of the practice and to introduce any newly adopted technologies. Patients tend to be quite receptive to new protocols, especially when presented as part of the normal screening procedures rather than as an exception based on clinician concern during the appointment.
The VELscope Vx device fits within the oral cancer prevention protocols of a dental practice. Clinicians can incorporate a two-minute examination into every hygiene appointment, take white-light and fluorescence images with the built-in camera system, and keep precise records of their patients’ oral health with a camera attachment.
Upon discovery of suspicious oral mucosal lesions, rapid follow-up is possible. The risk assessment test (when available) can be administered, referrals to specialists/surgeons can be accompanied with clear photographs and most importantly, the patient benefits from the favorable recovery statistics assoc
iated with early discovery.
ACCURATELY EXCISING CANCER TISSUES TO REDUCE RECURRENCES
Unfortunately, up to one third of those patients who receive treatment for oral cancer suffer from a recurrence at the primary site or a second primary tumor because the invariably larger abnormal tissue area is invisible under white light visualization. Reducing recurrence rates remains a challenge, but research indicates that fluorescence visualization technology may soon play a major role in this area as well. Preliminary results of the Canadian Optically-guided approach for Oral Lesions Surgical (COOLS) trial show that using tissue fluorescence visualization to define the field at risk for surgical resection can result in a marked reduction in recurrence rates at three years.
VELscope Vx technology is cleared to help surgeons determine the appropriate surgical margin when excision is indicated. Exciting new research published in Cancer Prevention Research (Poh et al.) describes a retrospective analysis comparing patients at the British Columbia Cancer Agency who had undergone surgical excision of cancerous lesions with and without the use of fluorescence visualization guidance using VELscope technology.1 Thirty-eight patients had VELscope-guided surgery, while 22 patients—the control group—did not. Follow up results on all patients revealed that seven of the 22 control group patients had experienced a recurrence of severe dysplasia or more serious tumors, while none of the patients who had VELscope-guided surgery experienced a recurrence of severe dysplasia or cancer.
A PIONEER IN ORAL CANCCER DISCOVERY
As a global leader in tissue fluorescence visualization technology, LED Dental’s core research has led to the development of the VELscope technology, a hand-held adjunctive screening device that has been used by several universities and cancer research organizations for studies backed by the Canadian National Institutes of Health with the support of more than $50 million in funding.
In 2006, the VELscope adjunctive device was cleared by the FDA and Health Canada for use in detecting pre-cancerous and cancerous lesions in oral mucosal tissues and to assist surgeons in determining the appropriate surgical margin when excision is indicated. Recognized by The World Health Organization, it is the world’s most frequently used tissue fluorescence technology, used to supplement the conventional comprehensive oral and head and neck exam.
A BRIGHTER FUTURE
It is possible to imagine a future where oral cancer doesn’t immediately bring to mind a low survival rate and radical, disfiguring treatments. New prevention protocols and powerful discovery, characterization and treatment technologies made possible through the “See to Treat” pathway, bring this preferred future within reach, and provide an opportunity for improved outcomes, physically, psychologically and financially. OH
Dr. David Gane is a member of the Canadian Dental Association, the American Dental Association and the American Academy of Oral and Maxillofacial Radiology, where he has served as Chairman of the Corporate Liaison Committee. Dr. Gane’s background as a dental surgeon offers him unique insights into the needs of both patients and dental care practitioners. He is committed to the development and implementation of innovative technologies to improve the patient experience.
Oral Health welcomes this original article.
Disclaimer: Dr David Gane, Chief Executive Officer, LED Medical Diagnostics Inc.
1. Poh C, Durham S, Brasher P, Anderson D, Berean K, McAulay C, Lee J, Rosin M, 2011, ‘Canadian Optically-guided approach for Oral Lesions Surgical (COOLS) trial: study protocol for a randomized controlled trial’, http://www.biomedcentral.com/1471-2407/11/462, BioMed Central Ltd., United Kingdom