Any discussion of diagnosis must be prefaced with the issue of discovery. While an annual screening for oral cancer is important, it is possible that you will notice some change in your mouth or throat that needs examination between your annual screenings. You are the most important factor in an early diagnosis. You should always contact your doctor or dentist immediately if you notice the following symptoms in yourself or a loved one:
- 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.
- Chronic hoarseness.
These symptoms may be caused by other, less serious problems, but they also indicate the possible presence of oral cancer. Only a professional will be able to tell you definitively. Some think that a visit to their medical doctor is the appropriate course of action. But remember that dentists are trained in this simple, quick screening, which involves the examination of the oral cavity as a whole and not just your teeth. 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. Your doctor will also 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. After the physical examination of your mouth, if your doctor finds any areas that are suspicious, he may recommend a biopsy. This is simply taking a small portion of the suspicious tissue for examination under a microscope.
The most traditional type of biopsy is incisional. It may be done by the doctor who examines you, or you may be referred to another doctor for the procedure. In an incisional biopsy, 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. When dealing with an area of significant mass, such as an enlarged lymph node, fine needle aspiration cytology (fine needle biopsy or FNB) 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 as the doctor draws back the piston of 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. In one study conducted during the early 80's by researchers Frable and Frable, a 92 percent accuracy rate was achieved in detecting the presence of tumors and 99 percent rate in correctly diagnosing benign cells with this technique. While there was an initial fear that this technique would lead to tumor cell seeding, pulling up additional cancerous cells through the outside of the needle tract, no confirmed cases of new growths attributable to this technique have been found. This is an issue with both fine needle and incisional biopsy. 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 with a scalpel or a pair of small tissue scissors snips it free of the surrounding tissue, removing a perfect plug of cells from the sampled area. As before 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 are doing 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.
The entire point of course, is that no treatment decisions should be made before there is confirmation of malignancy. Even in the case of what would seem to be an obvious malignancy, appearances can occasionally be misleading, hence the need for a proper biopsy. Also, the degree of differentiation between healthy and malignant tissues, along with the stage of the disease will influence treatment strategy and prognosis.
Other ways to determine the presence or extent of oral cancer exist. For instance, radiographs, also referred to as x-rays, can assist in determining the potential growth of a tumor into bone. While oral cancers unlike many other malignancies can usually be seen with the naked eye, some cancers are located internally in the body, making their detection difficult. Different scanning options, some of which assist in determining the presence of tumors or growths, and some of which can even detect malignancy, are necessary in these instances.
CT, 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 3mm 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. 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.
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.
Although less frequently used for oral cancer detection, ultrasonography is another way to produce pictures of areas in the body. 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 with in an area, if 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.
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 trying to carefully establish 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. After determining how much the cancer has spread, doctors also use this point of diagnosis to grade a cancer, which is a way of expressing how rapidly the cancer is spreading, if at all. The aggressiveness of this spreading 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 the speed with which it is spreading.
These staging tests and examinations almost always include incisional biopsy, and often one or more of the types of scans listed above. Most oral lesions allow for a small incisional biopsy, one that can be performed while the patient is conscious. Local anesthesia is adequate in most cases. For lesions or tumors in deeper tissues or less accessible areas, a general anesthetic can provide a better opportunity to perform the biopsy and also to make a full clinical assessment of the lesion.
Following biopsy confirmation of the presence of an oral cancer, a patient undergoes a thorough assessment of their overall health, and the state of their disease. The patient's overall fitness in anticipation of treatment is determined. Many patients afflicted by oral cancer, though certainly not all, are elderly. Older patients may be suffering from other illnesses, and they are also at risk of having other cancers in the respiratory or digestive tract. These "synchronous carcinomas" of the head and neck, lungs, or esophagus occur as frequently as 10 percent of the time with elderly oral cancer patients. Therefore, checking for cancer in these areas as well, can be part of the diagnostic process.
In many ways, the diagnostic stage of treatment affects everything that follows, and so care should be taken to both accurately and effectively determine the malignancy and stage of the cancer. This detailed diagnosis gives those prescribing treatment specific knowledge, which in turn allows for specific, more successful treatment.