Cancer is a group of many related diseases. All cancers begin in
cells, the body's basic unit of life. Cells make up tissues, and tissues make up the organs of the body.
Normally, cells grow and divide to form new cells as the body needs them. When cells grow old and die, new cells take their place. Sometimes this orderly process goes wrong. New cells form when the body does not need them, and old cells do not die when they should. These extra cells can form a mass of tissue called a growth or
tumor.
Tumors can be benign or malignant.
Benign tumors are not cancer. Usually, doctors can remove them. Cells from benign tumors do not spread to other parts of the body. In most cases, benign tumors do not come back after they are removed. Most important, benign tumors are rarely a threat to life.
Malignant tumors are cancer. They are generally more serious. Cancer cells can invade and damage nearby tissues and organs. Also, cancer cells can break away from a malignant tumor and enter the bloodstream or the lymphatic system. That is how cancer cells spread from the original (
primary) tumor to form new tumors in other organs. The spread of cancer is called
metastasis.
The Oral Cavity
Oral Cavity cancer starts and develops in the mouth. The Oral Cavity is comprised of several parts. They are:
The front two thirds of the tongue
The teeth
The gingiva (gums)
The buccal mucosa (the lining of the inside of the cheeks)
The floor (bottom) of the mouth under the tongue
The hard palate (the roof of the mouth)
and
The retromolar trigone (the small area behind the wisdom teeth)
The oral cavity helps you to breathe, talk, eat, chew, and swallow. Minor salivary glands located throughout the oropharynx make saliva that keeps your mouth moist and helps you digest food. And, It is composed of several types of body tissues, which are made up of several types of cells.
Squamous Cell Carcinomas
More than 90% of oral cavity cancers are squamous cell carcinomas, also called squamous cell cancers. Squamous cells are flat, scale-like cells that normally form the lining of the mouth and throat. Squamous cell cancer begins as a collection of abnormal squamous cells.
The earliest form of squamous cell cancer is called carcinoma in situ, meaning that the cancer cells are present only in the outer layer of cells called the epithelium. This is different from invasive squamous cell carcinoma, where the cancer cells have grown into deeper layers of the mouth.