Oral Cancer Screening

A healthcare professional can look for lumps, sores, patches of color or other abnormalities in your mouth. They may also use a brush-like tool or piece of cotton to collect cells for testing.


They might rinse your mouth with a special dye and shine a light in it to make healthy tissues look dark and abnormal ones appear white. Afterward, they might test the sample for cancer.

Visual Examination

It is important for healthcare professionals to visually examine the oral cavity for signs of pre-cancer or cancer. They may use a mirror to help with this, or they may also shine a light on your teeth and gums. The light will be reflected off of abnormal tissue, making it easier for the healthcare professional to spot it. A newer device called a VELscope uses fluorescent light to identify abnormal tissue, but it is not used as a substitute for visual examination in screening programs.

Screening in the oral cavity is challenging because early cancers do not always produce visible surface changes that a healthcare professional can see. Therefore, many early detection strategies rely on enhancing the effectiveness of visual examination with adjunctive aids such as toluidine blue dye and brush biopsy (see Diagnostic Studies–Brush Biopsy).

A single randomized trial found that systematic oral cavity visual examination improves case finding but does not significantly reduce death from mouth cancer. However, this trial was very small, and the study design lacked details of the randomization process, allocation concealment, and adjustment for covariates that might have affected the results.

Toluidine Blue Dye Test

The toluidine blue dye test is a simple and reliable method of assessing the degree of premalignant transformation in oral lesions. It is an acidophilic dye that binds to DNA and RNA in acidic environments, including those found in dysplasia and in situ carcinoma. The dye is used in semi-thin sections of resin embedded tissue to identify cellular structures, such as cell nucleus and nuclear envelopes. The dye does not stain the epithelium of normal oral mucosa.

The test is performed by applying a solution of toluidine blue (1% W/W) to the oral cavity for 20 sec. and then rinsing with 1% acetic acid to remove mechanically retained stain. The oral lesion is then observed under magnification for dark blue staining, light blue staining, or no colouring, and the lesion’s clinical status is recorded. Lesions that stain for a deep blue are considered positive and those that are not stained are negative.

Several studies have reported that toluidine blue preferentially stains OPLs with clinical features of high risk of progression: location on the floor and ventrolateral tongue (termed “high-risk sites”); large size; and a nonhomogeneous clinical appearance. It also correlates with histopathology and outcome in a number of studies.

A recent study has shown that toluidine blue is a valuable adjunct in assisting with the diagnosis of OPLs and may improve early detection of precancerous lesions by increasing diagnostic accuracy and by delineating areas of molecular risk. However, the authors caution that pathology report based on biopsy is still the gold standard to precisely and accurately diagnose each OPL, before a treatment modality can be determined.

Fluorescent Light Test

For this test, a dentist or dental hygienist places a toothbrush-sized probe in the mouth to feel around the base of the tongue where it begins to curve into the throat. The probe is then placed under a fluorescent light to show up any areas of tissue that may be abnormal. This is a very quick and painless procedure.

Cancer screening trials look for ways to find cancer earlier, when it’s easier to treat and the chances of survival are higher. But scientists also study screening tests to see whether they have the right balance of benefits and harms. So far, no screening test has been shown to lower a person’s risk of dying from oral cavity and oropharyngeal cancer when it is detected at an early stage.

Despite the lack of evidence, some programs have tried to improve outcomes by increasing screening coverage and implementing innovative models. For example, the Cuban program used “case finding” to identify cancers before they were detected as symptoms, and this resulted in a favorable “stage shift,” with more cases being diagnosed at a less advanced stage (Sankaranarayanan et al. 2002).

Other methods to augment visual examination have been developed, including the use of brush biopsy and a fluorescent light test (FLUO), but none has been rigorously tested in prospective oral cancer screening trials. Novel diagnostic tests that use salivary or serum have not been extensively tested, but some researchers have shown that they can detect different markers of pre-cancerous and cancerous tissues.


A biopsy is an important part of oral cancer screening. It involves removing a small sample of tissue (such as the lining of your mouth or the base of your tongue) and sending it to a laboratory to see if it contains cancer cells. If your doctor discovers abnormal cells, they may recommend additional testing to get a diagnosis.

The front of the mouth and the back of the throat — called the oropharynx — are a common place for cancer to develop. This type of cancer is more often linked to tobacco and heavy alcohol use, but it can also be caused by the HPV virus, which can cause cervical cancer and other types of health problems.

To check for signs of pre-cancerous or cancerous tissue, your healthcare provider will rinse your mouth with a special blue dye before the exam. Then they’ll shine a light in your mouth, which makes healthy tissues appear dark and abnormal tissue look white. They’ll carefully examine the inside of your mouth, neck and jaw for asymmetries, swellings, bumps or patches of color, and they’ll palpate, or feel, the area around your ears, nose and chin. They’ll also check for enlarged lymph nodes in the neck, which can be a sign of cancer spread. They’ll take out your dentures if necessary to get an even better view of your mouth and the structures behind it.