Oral cancer is a killer. In the United States alone, there are over 22,000 cases every year and over 5,000 deaths yearly, according to the US National Cancer Institute.

The emergence of oral cancer does not happen overnight. The slow but sure process is common in people between the ages of 60 and 70 who have been smoking for years, drinking alcohol heavily, and have a family history of the disease. Betel nut chewing is another cause of oral cancer.

"Oral cancer is very common in tobacco-growing regions of the world. I have yet to see oral cancer in someone younger than 60. It's a slow process - and a slow death," said Dr. Alberto Calderon, an ENT specialist and diplomate of the Philippine Board of Otolaryngology.

The disease is not only confined to the mouth but may affect the tongue, buccal mucosa (inside of the checks for tobacco and betel nut chewers), gums, lips (for pipe smokers) and palate (roof of the mouth for inverted cigarette smokers). Symptoms include a small, pale lump or discolored thickening in any of these areas.

"The earliest symptom of oral cancer is leukoplakia, a thick white patch inside the mouth. Eventually, there is swelling, pain and inflammation. Ulcers and swollen lymph nodes under the jaw later form," Calderon explained.

Leukoplakia is the body's natural defense against the heat of smoking, ill-fitting dentures or a rough tooth. The patches arc not necessarily cancerous but may develop into cancer later. How does this happen?

"Tobacco- and betel nut are harsh substances. Whether they are inhaled or chewed, they are unnatural - not food or anything. Because of this, the body fries to defend itself from these substances by forming a protective layer on the affected areas in much the same way that a person with ill-fitting shoes develops calluses. In the course of defending itself by forming thick white patches in the mouth, some body cells go out of control and continue growing. That uncontrolled new growth emerges as cancer," Calderon revealed.

Early detection can save one from oral cancer. Unfortunately, most cases go unnoticed and delayed treatment often results in death.

"More than half of all mouth cancers are well advanced at the time of their detection. Often they spread into nearby lymph nodes of the neck. This requires treatment that is more extensive. The chance of a cure is diminished. Almost 25 percent of people with oral cancer die because of delayed discovery and treatment," said Dr. David E. Larson, editor-in-chief of the "Mayo Clinic Family Health Book."

How do you avoid this situation? First, Calderon said you should be aware of the signs of oral cancer and report these to a physician or dentist, particularly one who is an expert in oral medicine. A doctor who is familiar with oral diseases can easily diagnose the problem and take the necessary steps to save the patient.