Cancer refers to abnormal growth of cell tissues. When it affects any part of the oral cavity, it is called oral cancer.
An oral cancer screening is an examination performed by the dentist or oncologist to look for signs and symptoms of cancerous or precancerous conditions in your mouth.
The goal is to identify mouth cancers early, thus increasing the chances for the cure.
During the screening, your dentist may use many tools to look for any discoloration or mouth sores in your mouth and feel the tissues around your mouth for any lump or abnormality.
If any abnormality is present in your mouth, a sample of it is collected and sent to a lab for further testing.
Continue reading to know more about the screening of oral cancer- its importance and the various diagnostic aids used in the procedure.
Why is the screening performed?
The incidence of oral cancer has increased in recent years. Early diagnosis and treatment are essential for the long-term survival of an individual.
The benefit of oral cancer screening is more when done in the early stages. Cancerous or precancerous lesions found at an early stage are easy to remove and are most likely to be cured.
Oral cancers precede by abnormal tissue changes or lesions that you may not even know about it.
Since you may or may not experience any symptoms, these lesions get identified during routine dental checkups or oral screenings.
It is essential to find, monitor, and manage precancerous lesions, because with time they may develop into oral cancer.
What are the risk factors?
Here are some key factors for oral cancer to help you determine if you are at risk:
- Chemical irritants (tobacco, alcohol, mouthwashes with high alcohol content)
- Physical irritants(Denture use, prolonged denture irritation, irregular teeth or restoration, chronic cheek biting habits)
- Nutritional factors (deficiency of vitamin A and carotenoid supplementation)
- Age (40 or older)
- Prolonged sun exposure
- Oral Human papillomavirus (HPV)
- Gender (Men are more susceptible than women) (1)
- History of other cancers
Patients with oral cancer mostly report with these risks, but sometimes oral cancer occurs in those who have no risk factors at all.
Therefore, if you don’t have any risk factors mentioned above, oral cancer screenings are still important in maintaining your overall health.
Signs and symptoms of oral cancer
You must keep an eye out for the following signs and symptoms that may indicate the presence of oral cancer –
- A jaw or dental pain
- Loose teeth
- Unexplained bleeding
- Pain or difficulty swallowing
- Unexplained ear pain
- Sensory and motor nerve compromise
- Difficulty in speech articulation
- Growing lesions (red or white patches in the mouth or tongue)
Procedures involved in oral cancer screening
- Standard screening- conventional intraoral and extraoral examination
- Established screening – oral cytology, oral brush cytology
- Vital tissue staining – toluidine blue, methylene blue, Lugol’s iodine
It includes routine clinical examination by the dentist. Your dentist will check the areas inside and outside of mouth by two methods- inspection and palpation.
- Intraoral examination – includes all areas inside your mouth
- Extraoral examination – includes areas of the head and neck region such as TMJ, masticatory muscles, skin, facial form, lymph nodes of head and neck region
The only drawback with the conventional examination is it cannot identify all potentially premalignant lesions.
It is the study of cells which exfoliate or abrade from the body surface. When epithelium becomes the seat of any pathology, cells lose their cohesiveness and cells present in deeper layers may shed along with superficial cells.
Drawback: the sensitivity and specificity differ due to its subjectivity or due to poor technique in obtaining cells and smear preparation.
Brush Biopsy (Oral CDx)
- It is a simple, relatively inexpensive, highly sensitive, risk-free method of screening for cancer
- In this technique, oral cells are obtained by scraping the surface of the mucosa, by rinsing the oral cavity or by taking a sample of saliva from the patients.
- Slides are scanned by the OralCDX computer system that consists of a neural- network based image processing system specifically designed to detect oral epithelial pre-cancerous and cancerous cells.
Some stains are used intraorally to differentiate cancerous cells from the normal ones. Each stain has its properties.
- Toluidine blue (tolonium chloride) is a vital metachromatic dye that stains nucleic acids and abnormal tissues. It demarcates the extent of the lesion.
- A dark blue color on tissue is interpreted positive for lesions suspicious of malignancy.
- The light blue color is interpreted positive for premalignant lesions, proved otherwise by biopsy.
- Around 30% of false-positive results are related with this dye. (2)
- Similar to toluidine blue dye, it is less toxic to the human body.
- It is acidophilic and may penetrate cells with an abnormal increase in nucleic acids, thus resulting in different uptake between normal and highly dysplastic and malignant cells. (3)
- It has also helped to identify the areas of incomplete excision during peripheral osteotomy of aggressive lesions like odontogenic keratocyst (OKC) and ameloblastoma. (4)
- Lugol’s solution consists of potassium iodide and iodine.
- The normal mucosa contains a higher amount of glycogen than abnormal mucosa and produces brown-black stain for differentiation between tissues.
Modern devices used for screening
- Velscope is a portable device that allows direct visualization of the oral cavity.
- It does not diagnose oral cancer. It is just an adjunct to the oral examination.
- It follows the principle of fluorescence imaging.
- This technology stimulates epithelial cells and stroma by blue light (400 – 460 nm).
- It is the self-fluorescence property of the tissues that allows detection of changes in morphology and composition of tissues in a non-evasive manner.
- It is a versatile, 3-in-1 dental device that includes a handheld LED light source and three interchangeable diagnostic instruments.
- This instrument works in conjunction with a mild acetic acid rinse to improve the visualization of oral lesions.
- It is a screening device that allows the clinician to visualize suspicious lesions more easily.
- The kit contains a chemiluminescent device; 30 ml acetic acid and light stick holder/retractor.
- Normal epithelium absorbs the light and appears dark and abnormal tissues reflect light and appear bright white.
What happens after screening?
If your dentist is suspicious about a lesion in your mouth, he may refer to some diagnostic tests for confirmation for any malignancy.
If no abnormality gets detected in your oral cavity, your dentist may ask you to return at regular intervals for further screening especially if you are at a higher risk of oral cancer.
An oral cancer screening is a precautionary measure which examines your oral cavity for any precancerous lesion that may affect your life.
There has been an alarming and a steady increase in the incidence of oral cancers occurring below the age of 40, and in particular females, without identifiable risk factors.
In cases of oral cancer, precancerous lesions or abnormal tissue changes occur that you may not be aware of it.
Therefore, it is crucial to find, monitor, and manage such lesions, because with time they may develop into oral cancer.
You must keep in mind the risk factors and adapt to a healthy lifestyle to reduce the risk of oral cancer.
Early detection of oral cancer will help in its cure as cancer that reaches an advanced stage may cost you your life!