Figure 1. VELscope examination. The clinician shines the blue excitation light into the patient’s oral cavity and looks through the Handpiece.
Figure 2. Illustration of VELscope’s principle of operation.
Figure 3. Representative examples of direct visualization under both white light and VELscope examination - photos courtesy of the British Columbia Oral Cancer Prevention Program.
No apparent lesion	Normal fluorescence pattern
Visible leukoplakia	Irregular, dark area visible under fluorescence visualization. Biopsy-confirmed severe dysplasia
No apparent lesion	Irregular, dark area visible under fluorescence visualization. Biopsy-confirmed Carcinoma in Situ (CIS)

Risk Factors

Understanding the causative factors of cancer will contribute to prevention of the disease. Age is frequently named as a risk factor for oral cancer, as most of the time it occurs in those over the age of 40. The age of diagnosed patients may indicate a time component in the biochemical or biophysical processes of aging cells that allows malignant transformation, or perhaps, immune system competence diminishes with age. However, it is likely that the accumulative damage from other factors, such as tobacco use, are the real culprits. It may take several decades of smoking for instance, to precipitate the development of a cancer. Having said that, tobacco use in all its forms is number one on the list of risk factors. At least 75% of those diagnosed are tobacco users. When you combine tobacco with heavy use of alcohol, your risk is significantly increased, as the two act synergistically.Those who both smoke and drink, have a 15 times greater risk of developing oral cancer than others.

Tobacco and alcohol are essentially chemical factors, but they can also be considered lifestyle factors, since we have some control over them. Besides these, there are physical factors such as exposure to ultraviolet radiation. This is a causative agent in cancers of the lip, as well as other skin cancers. Cancer of the lip is one oral cancer whose numbers have declined in the last few decades. This is likely due to the increased awareness of the damaging effects of prolonged exposure to sunlight, and the use of sunscreens for protection. Another physical factor is exposure to x-rays. Radiographs regularly taken during examinations, and at the dental office, are safe, but remember that radiation exposure is accumulative over a lifetime. It has been implicated in several head and neck cancers.

Biological factors include viruses and fungi, which have been found in association with oral cancers. The human papilloma virus, particularly HPV16 and 18, have been implicated in some oral cancers. HPV is a common, sexually transmitted virus, which infects about 40 million Americans. There are about 80 strains of HPV, most thought to be harmless. But 1% of those infected, have the HPV16 strain which is a causative agent in cervical cancer, and now is linked to oral cancer as well. There are other risk factors which have been associated with oral cancers, but have not yet been definitively shown to participate in their development. These include lichen planus, an inflammatory disease of the oral soft tissues.

There are studies which indicate a diet low in fruits and vegetables could be a risk factor, and that conversely, one high in these foods may have a protective value against many types of cancer.

Early Detection

Historically, it has been difficult to determine which abnormal tissues in the mouth are worthy of concern. The fact is, the average person routinely has conditions existing in their mouths that mimic the appearance of pre-cancerous changes, and very early cancers of the soft tissues. One study determined that the average dentist sees 3-5 patients a day who exhibit soft tissue abnormalities, most of which are benign in nature. Even the simplest things, such as a canker sore (herpes simplex), the wound left by accidentally biting the inside of your cheek, or sore spots from a poorly fitting prosthetic appliance or denture, all at first examination, share similarities with dangerous lesions. Some of these conditions cause physical discomfort, others are painless. The question is which ones deserve action, and which ones bear watching and waiting?

There has been a tendency to watch these areas over an extended period to determine if they are dangerous or not. Unfortunately, this philosophy leads to a situation in which a dangerous lesion may continue to prosper and grow into a later stage, hard to cure cancer. Any sore, discoloration, induration, prominent tissue, irritation, hoarseness, which does not resolve within a two week period on its own, with or without treatment, should be considered suspect and worthy of further examination or referral. Besides a routine visit to the dental office for regular examinations, it is the patient's responsibility to be aware of changes in their oral environment. When these changes occur, they need to be brought to the attention of a qualified dental professional for examination. The dental professional needs to be current in the knowledge base necessary to make a proper diagnosis, and be competent in the proper screening procedures to identify oral cancer.

How to know if you have had a proper oral cancer screening

There are two separate issues, discovery and diagnosis. Discovery is the result of a thorough visual and manual examination. A protocol for a comprehensive oral cancer screening appears elsewhere in this section of the web site. It includes a systematic visual examination of all the soft tissues of the mouth, including manual extension of the tongue to examine its base, a bi-manual palpation of the floor of the mouth, and a digital examination of the borders of the tongue, and the lymph nodes surrounding the oral cavity and in the neck. New diagnostic aids, including lights, dyes, and other techniques are beginning to appear on the marketplace. While making the discovery process more effective, it is still possible to do a comprehensive examination through a proper visual and tactile process.

Once suspect tissues have been detected, the only way a definitive diagnosis of oral cancer may be made is through biopsy. Given the large number of tissue abnormalities a dentist sees every day, it is not logical, nor practical, that each one of these be biopsied. The first question which may help in the determination of which abnormality bears closer examination, is how long has the suspect condition been present? Any condition that has existed for 14 days or more without resolution should be considered suspect and worthy of further diagnostic procedures or referral. Certainly, it is common knowledge that two of the most prevalent lesions that mimic oral cancer, are the herpes simplex ulceration, and aphthous ulcerations, each resolving of their own accord in approximately 10-14 days. Perhaps that sentence should be underlined, since one of the most common diagnoses received with referred patients to a major university cancer pathology department is "an atypical herpetic/aphthous lesion" These all too frequently turn out to be squamous cell carcinomas, which have been under observation.... for several months.

Still, it would seem impractical at these early timelines to engage in biopsy. A oral biopsy brush is available that makes this decision to get an early diagnosis through biopsy easier to make. Simple, painless, and accurate diagnosis of soft tissue abnormalities can be obtained through its use.

Note that this system is not designed to provide the kind of information, specifically cellular architecture, that would be obtained through a punch or incisional biopsy. But it will provide an answer to the question of whether malignancy exists or not, through a quick, minimally invasive, and inexpensive procedure. Should positive results be returned through this system, the brush biopsy must be followed by a conventional biopsy procedure for confirmation. The strong argument for the brush biopsy is that it eliminates the waiting and watching of a suspicious lesion, while it develops from a highly treatable and curable, early stage localized cancer, into a life threatening late stage malignancy. Positive identification of oral cancers at the earliest stages, result in the best prognosis for cure and long-term survivability.

Creating awareness, discovery, diagnosis, and referral. When it comes to oral cancer and saving lives, these are the primary responsibilities of the dental community. The most important step in reducing the death rate from oral cancer is early discovery. No group has a better opportunity to have an impact than members of the dental