By David Morgan, PhD
What Exactly is Adjunctive Oral Cancer Screening?
With the rise of oral cancer cases in North America, largely attributed to a strain of the human papillomavirus (HPV), oral cancer screening is more important than ever before. In fact, the American Dental Association recommends a visual and tactile comprehensive oral examination (COE) to be routinely performed to support early discovery and diagnosis of oral cancer and/or pre-cancer in patients of dental practices. This visual and tactile examination is the absolute minimum dental practices should do for their patients concerning oral cancer screening. Adjunctive oral cancer screening technologies are used in conjunction with the COE to help detect abnormalities and provide additional information to be utilized in the clinical decision-making process.
The Purpose of Adjunctive Oral Cancer Screening
It is essential to understand that adjunctive screening should never be performed without a thorough physical examination of the oral cavity under white light accompanied with a tactile assessment of the head, neck and oral cavity.
The majority of adjunctive screening methodologies are non-diagnostic, meaning they will not give a positive or negative result in relation to whether a patient has oral cancer. Because oral cancer can often go unnoticed to the naked eye, many adjunctive technologies aim to enhance the visualization of these areas of concern so that they will be more noticeable and, hopefully, reduce the likelihood that abnormal mucosa is overlooked. The information provided by adjunctive screening together with the information from the COE is then used to contribute to the clinician’s decision-making process for referring patients to a specialist for biopsy.
Types of Adjunctive Oral Cancer Screenings Technologies
There are several different adjunctive screening technologies that can be utilized to aid in visualizing oral abnormalities, including:
- Vital tissue staining
Vital Tissue Staining
Vital tissue staining utilizes a chemical called Toluidine Blue (ToB), which is a dye that is absorbed by unhealthy mucosa, giving areas of concern a dark blue color. These dark areas are then considered to be areas of concern that warrant further investigation.
Chemiluminescence, marketed under the brand Vizilite, is considered the first adjunctive device for oral screening that hit the market around 15 years ago. This technology combines application of an acetic acid solution with the use of a blue-white light to help identify abnormal mucosa. The acetic acid solution is swished in the mouth for 1-2 minutes, dehydrating the mucosa to accentuate keratinized tissue. A chemiluminescent light is then utilized to accentuate oral mucosal abnormalities.
Autofluorescence relies on the use of specific wavelengths of light interacting with fluorophores that are naturally present in most human tissues. When exposed to certain light wavelengths, fluorophores become excited and re-emit light of varying colors. Abnormal mucosa impacts the spectral properties of the tissue, allowing detection through special optical filters. The VELscope is an example of an autofluorescence technology, in addition to the Vizilite Pro and Oral ID systems.
Another adjunct to the traditional COE is cytopathology, which involves the collection of cells from a suspected lesion and viewing them under a microscope to inspect for abnormalities. One example of a cytopathology system is the Oral CDx Brush Test, which uses a special brush to remove cells from a suspected lesion which are then sent to a lab for microscopic review.
Role of Biopsy
Biopsy is the gold-standard for histopathologic diagnosis of lesions . It involves physical sampling of the suspect tissue, samples of which are then examined by a pathologist under a microscope who produces the histopathologic diagnosis. This diagnosis and consideration of patient history is then used to plan appropriate treatment for the patient.
Effectiveness of Adjunctive Screening Technologies
The COE is certainly aided by the incorporation of adjunctive technologies with regard to identifying oral mucosal abnormalities. While the COE is often efficient in locating areas of concern that are obvious to the naked eye, there is increased difficulty observing less obvious lesions or abnormalities. The addition of an adjunctive technology helps make visualization of abnormal tissues more apparent.
A study in the Journal of the American Dental Association argues that the comprehensive visual and tactile examination performs poorly in locating oral squamous cell carcinomas in their earliest stages, where treatment and outcomes are more favorable. The researchers conclude that the comprehensive oral examination could be improved with the implementation of adjunctive technologies, which can subsequently contribute to the visualization of dysplastic lesions.
Again, neither the COE nor adjunctive screening technologies provide a definitive diagnosis as to the exact nature of the abnormality but can assist in providing information that can be utilized in the referral decision-making process.
So What is Adjunctive Oral Cancer Screening?
To conclude, adjunctive oral screening is an additional process that provides supplemental information to be used in conjunction with a COE. Adjunctive technologies can also help ensure that areas of concern do not go unnoticed and are visualized in early stages. By taking a holistic view of all information obtained through acquisition of patient medical history, the COE and adjunctive screening, clinicians can make more informed decisions regarding patient referral and treatment.
2 Epstein, et al. The limitations of the clinical oral examination in detecting dysplastic oral lesions and oral squamous cell carcinoma. JADA. 2012; 143. 1332-1342