While an bi-annual screening for oral cancer is important, a medical professional should be consulted earlier if the following changes are noted - a sore or lesion in the mouth that does not heal within two weeks, a lump or thickening in the cheek, a white or red patch on the gums, tongue, tonsil, or lining of the mouth, a sore throat or a feeling that something is caught in the throat, difficulty chewing or swallowing, difficulty moving the jaw or tongue, numbness of the tongue or other area of the mouth, swelling of the jaw that causes dentures to fit poorly or become uncomfortable, and chronic hoarseness. These symptoms can be warning signs of oral cancer.
DETAILED PATIENT HISTORY
The first step to diagnosis is taking a thorough patient history. Any person with a history of tobacco and alcohol use or prior head and neck malignancy has a significant risk. However, equally important, 1 in 4 oral cancers are detected in people over 50 who do not smoke or drink alcohol. Current research also indicates that HPV 16-18 is rapidly changing traditional statistics. Younger, non-smoking patients under 50 are the fastest growing segment of the oral cancer population. This increase in oral cancers that is being found in people in their 20’s and 30’s is rapidly replacing those caused by tobacco since the use of tobacco products has declined in the US for more than a decade now. However, during this time, the incidence rate of oral cancer has actually increased. As in many cancers, the symptoms and history will often lead the dentist/physician to not only the presence of a cancer but also the likely site of the lesion. Tobacco/alcohol lesions tend to favor the anterior tongue and mouth, and HPV positive lesions tend to favor the posterior oral cavity.
The first step in diagnosis is a thorough oral screening. The doctor will check the mouth for white patches, red patches, ulcerations, lumps, loose teeth, and review your dental x-rays for abnormalities. Be sure to tell the doctor if you have been a tobacco user in any form. Tobacco use is implicated in many cases of oral cancer. Besides a visual examination of all the tissues in your mouth, your doctor will feel the floor of your mouth and portions of the back of your throat with his fingers, in the search for abnormalities. A thorough oral screening also includes indirect examination of the nasopharynx and larynx and involves manually feeling the neck for swollen lymph nodes, and other abnormalities such as hardened masses.
After the physical examination of your mouth, if the doctor finds any areas that are suspicious, a incisional biopsy is recommended. This is simply taking a small part of the suspicious tissue for examination under a microscope.The doctor will remove part or all of the lesion depending on its size and his ability to define the extent of it at this early stage. The sample of tissue is then sent to a pathologist who examines the tissue under a microscope to check for abnormal, or malignant cells. Another form of incisional biopsy is referred to as a punch biopsy. In this case, a very small circular blade is pressed down into the suspect area cutting a round border. The doctor then pulls on the center of this area, and snips it free of the surrounding tissue, removing a perfect plug of cells from the sampled area. This is sent to a pathologist for examination. The area where the plug was removed will not bleed much and heals normally without the need for any stitches since it is so small. Some dental offices do a brush biopsy where a sampling of cells is collected by aggressively rubbing a brush against the suspect area. While this has some usefulness in preliminary evaluation of a suspect area, it is not a stand-alone procedure, and if a positive find returns, this must be confirmed by a conventional incisional biopsy.
FINE NEEDLE ASPIRATION CYTOLOGY
When dealing with an area of significant mass, such as an enlarged lymph node, fine needle aspiration cytology has found an increasing role in diagnosis. The technique is reliable and relatively inexpensive. In it, a small needle attached to a syringe is inserted into the questionable mass, and cells are aspirated, or pulled out into the syringe. The success of this method depends on how accurately the needle is placed, and, as with all biopsies, on the skill and experience of the tissue pathologist who will be examining the cells. It is likely that the doctor will insert the needle and draw out cellular material from several different locations in the mass to ensure that a thorough and representative sample has been taken.
RADIOGRAPHS AND CAT SCANS
Radiographs can assist in determining the potential growth of a tumor into bone. While most oral cancers are soft tissue based, some cancers are located internally in the body, making their detection difficult visually or by biopsy. Different scanning options are necessary in these instances. CT Scan or CAT (co-axial tomography) scan technology has developed rapidly over the last few decades, and these scans can provide images of great diagnostic quality and usefulness. A CT scan could be described as a series of x-rays, each one a view of a 3 mm section of the area being scanned, which are then manipulated by a computer, allowing doctors a dynamic view of the affected soft tissue areas of the body with much greater detail than a simple x-ray. However, CT is only able to detect the actual presence of masses, and only a biopsy can verify that the mass is malignant.
MAGNETIC RESONANCE IMAGING
Another recent technology, Magnetic Resonance Imaging (MRI), is helpful in providing accurate views of the affected area. MRI is a procedure in which pictures are created using magnets and radio frequencies linked to a computer imaging system. The hydrogen atoms in the patient’s body react to the magnetic field and emit signals that are analyzed by a computer to produce detailed images of organs and structures in the body. Occasionally a dye is injected into the bloodstream during scanning to bring greater detail to the soft tissue areas of the scan. Again, this procedure is only able to detect the actual presence of masses, and it still requires a biopsy for confirmation.
POSITRON EMISSION TOMOGRAPHY
PET, or Positron Emission Tomography, provides another kind of image of the body’s interior. Instead of taking a picture of the bones, like an X-ray, or the internal organs and soft tissue, like a MRI, PET scanning lets doctors display the body’s actual metabolism. Since cells use a simple sugar, glucose, as a source of energy, PET can track down how much glucose is being metabolized in different areas of the body. Because cancer cells are dividing rapidly, they break down glucose much faster than normal cells. The increased activity will show up on a PET scan and can indicate both primary and metastatic tumors.
ULTRASOUND AND RADIONUCLIDE SCANNING
Ultrasonography is another way to produce pictures of areas in the body, although less frequently used for oral cancer detection. In it, high-frequency sound waves (ultrasound) are bounced off organs and tissue. The pattern of echoes produced by these waves creates a picture called a sonogram. It is useful in finding masses within an area, if visual examination and palpation discloses something of questionable nature. Radionuclide scanning can show whether cancer has spread to other organs elsewhere in the body. In it, the patient swallows or receives an injection of a mildly radioactive substance, and a scanner measures and records the level of radioactivity in certain organs to reveal abnormal areas.
While all these types of scans are still used largely for confirmation or measuring extent, the best indicator of tumor involvement is still the clinical assessment, relying on both direct examination of the area as well as biopsy. The ability to detect cancer at the earliest stages, as well as its precise location in the body, can improve the survival rate of this disease, and allow for less disfiguring ways to address the tumors and lesions associated with oral cancer. If the pathologist examining the cells from a patient finds oral cancer, the patient’s doctor needs to know the stage, or extent, of the disease in order to plan the best treatment. Staging a cancer involves establishing the degree to which the cancer has spread, and to what extent it involves other areas of the mouth and neck, or even distant locations elsewhere in the body. This is described using the terms well differentiated, moderately differentiated, or poorly differentiated. A well-differentiated cancer is not overly aggressive in the rate it is spreading; a moderately differentiated cancer is intermediately aggressive; and a poorly differentiated is much more aggressive in its extent and the speed with which it is spreading.