What is the best way to screen for oral cancer? Are special oral cancer screening tests better than an oral exam?

Answers from Alan Carr, D.M.D.

Most dentists perform an examination of your mouth during a routine dental visit to screen for oral cancer. Some dentists may use additional tests to aid in identifying areas of abnormal cells in your mouth. The goal with oral cancer screening is to identify cancer early, when there is a greater chance for a cure.

Screening for oral cancer isn't without controversy, though. No single oral exam or oral cancer screening test is proven to reduce the risk of dying of oral cancer. Still, you and your dentist may decide that an oral exam or a special test is right for you based on your risk factors.

Oral exam for oral cancer screening
Most dentists recommend an oral exam during your routine dental visit to screen for oral cancer. During an oral exam, your dentist looks over the inside of your mouth to check for red or white patches or mouth sores. Using gloved hands, your dentist also feels the tissues in your mouth to check for lumps or other abnormalities.

Many people have abnormal sores in their mouths, with the great majority being noncancerous. An oral exam can't determine which sores are cancerous and which are not. If your dentist finds an unusual sore, you may go through further testing to determine its cause. The only way to definitively determine whether you have oral cancer is to remove some abnormal cells and test them for cancer in a procedure called a biopsy.

Not all medical organizations agree about the benefits of an oral exam for oral cancer screening. For instance, the American Dental Association recommends all adults undergo periodic oral exams when they visit the dentist. The American Cancer Society recommends discussing oral cancer screening when you visit your dentist. But the U.S. Preventive Services Task Force (USPSTF) concludes that there is insufficient evidence either for or against routine oral cancer screening in adults. The USPSTF also says that techniques other than the standard oral exam are being evaluated but are still experimental.

Additional tests for oral cancer screening
Some dentists use special tests in addition to the oral exam to screen for oral cancer. It's not clear if these tests offer any additional benefit over the oral exam. Special oral cancer screening tests include:

  • Rinsing your mouth with a dye before an exam. Your dentist may apply a blue dye to the inside of your mouth or ask you to rinse your mouth with a blue dye before your oral exam. Abnormal cells in your mouth may take up the dye and appear blue. The blue dye can't distinguish between cancerous cells and noncancerous cells, so for people with an average risk of oral cancer this test isn't as helpful. Some studies have concluded there could be some benefit for people with a very high risk of oral cancer, such as those who've already been diagnosed with one oral cancer and have a risk of a second cancer.
  • Shining a light in your mouth during an exam. Your dentist may use a special light to examine the inside of your mouth. The special light makes healthy tissue appear dark and makes abnormal tissue appear white. Some researchers have reported finding abnormal areas with the special light that weren't discovered during a standard oral exam. But most studies haven't found this to be the case in general. There's little evidence that using a special light to examine the mouth has any advantage over a standard oral exam.

Special tests for oral cancer screening aren't always covered by dental insurance. Some tests may be covered if you have a high risk of oral cancer or if your dentist has discovered an area of abnormal cells in your mouth.

Who should consider oral cancer screening
People with a high risk of oral cancer may be more likely to benefit from oral cancer screening, though studies haven't clearly proved that. Factors that can increase the risk of oral cancer include:

  • Tobacco use of any kind, including cigarettes, cigars, pipes, chewing tobacco and snuff, among others
  • Heavy alcohol use
  • Previous oral cancer diagnosis

Ask your dentist whether oral cancer screening is appropriate for you. Also ask about ways you can reduce your risk of oral cancer, such as quitting smoking and not drinking alcohol.

Sep. 10, 2011 See more Expert Answers