Generally speaking, screening is a process through which doctors look for cancer before there are any symptoms of the disease. The purpose of screening is to find cancers earlier, when they are more effectively treated. Indeed, by the time symptoms of cancer appear, there is a good chance that the cancer has already started to spread. Through screening, doctors can gain valuable information about which people are more likely to be diagnosed with particular kinds of cancer. We can study the activities and environments of different people and try to determine which activities and environments are associated with different cancers. Patients should be careful to remember that if a doctor is screening for cancer, this does not mean you have it nor does it mean s/he believes you have cancer. Screening occurs when there are no obvious symptoms of cancer.
More specifically, oral cancer screening involves looking for signs of cancer in the lips, oral cavity, and oropharynx. In addition to the lips, oral cancer may be found in these areas:
- The front of the tongue
- The gums
- The lining of the cheeks
- The bottom of the mouth, under the tongue
- The palate at the front of the mouth (hard palate)
- Behind the wisdom teeth
- The pharynx
- The back of the tongue
- The palate at the back of the mouth (soft palate)
- The side and walls of the throat
- The tonsils.
As such, oral cancer screening involves diagnostic tests that screen these regions. During routine medical or dental check-ups, your doctor or dentist will start by searching for lesions in the oral cavity and oropharynx. Oral cancers usually start in the thing, fat cells that line these oral regions. Abnormal white patches of cells (leukoplakia) and abnormal red patches of cells (erythroplakia) that form on the mucous membranes may become cancerous; so if your doctor finds these lesions the tissue will need to be tested.
There are four basic methods of testing oral cells to determine if they are cancerous.
- Toluidine blue stain
- Fluroescense staining
- Exfoliative cytology
- Brush biopsy
A diagnostic procedure in which oral cells are covered with a blue dye is known as a toluidine blue stain. Areas that are darker are more likely to be or become cancer. With fluorescence staining, lesions in the mouth are inspected under a certain type of light after the patient has rinsed with a fluorescent mouth wash; normal tissue can be distinguished from cancerous tissue using this test. Exfoliative cytology involves collecting cells from the lips and/or oral cavity with a piece of cotton, a brush, or small wooden stick. Cells are scraped from the lips, tongue, mouth, or throat and viewed under a microscope to look for signs of cancer. Finally, a brush biopsy procedure involves removing cells with a brush designed to collect cells from a lesion; again, cells are viewed under a microscope to find out if they are cancerous.
More than half of oral cancers have already spread to the lymph nodes by the time they are discovered. As such, it is important to have regular check-ups from a dentist that includes oral cancer screening.