What is Cancer?
Cancer is the term for a group of several diseases that affect the cells of different body parts like your lungs, breasts, prostate, colon, liver, and skin, among others. Each cancer disease is usually named for the body part or for the cell type in which the cancer started. So what does each cancer disease have in common?
Cancer causes certain cells to grow and divide uncontrollably.
To understand what these cancer diseases have in common, you first want to understand your body’s cells. Cells are the smallest functional unit in your body. Your body tissues, organs, and blood are all made up of millions and millions of tiny cells. These cells, when they work the way they’re intended, constantly change, grow, and divide to support your body’s functions.
But cells affected with cancer grow and divide in unusual ways. These abnormal cancer cells often form a lump or a mass called a tumor. Tumors are generally categorized in one of two ways: noncancerous (benign) or cancerous (malignant). Malignant tumors are dangerous and are likely to cause death if left untreated.
Tumors sometimes invade other body parts and spread the cancer disease. This process happens when cells break away from the tumor and travel through your body through your bloodstream or lymph system. This is called metastasis.
Now that you know some facts, you probably have more questions.
The Five Most Common Questions about Cancer
What causes cancer? The exact cause of cancer is currently unknown, but clear risk factors are evident for many cancers. Some factors can be avoided and some cannot. For example, whether or not you smoke is something you can control. A family history of breast cancer prior to age 50 isn’t something you control. Learn more about these common cancers to understand your risks.
What are the stages of cancer? Stages describe how much a cancer has spread. Also referred to as the TNM classification, the cancer stages include:
- The size of the tumor (T)
- How many (if any) lymph nodes (N) are involved
- Whether or not the cancer has metastasized (M)
A number (zero to four) is assigned to each of the three categories to indicate severity. The higher the number, the more severe the stage.
What is oncology? Oncology is the branch of medicine that specializes in cancer. Doctors of oncology, oncologists, diagnose and treat cancer. Types of oncology specialists include:
- Medical oncologists who focus on medical cancer treatments such as chemotherapy.
- Surgical oncologists who specialize in surgical tumor removal.
- Pathologists who microscopically examine cells and tissues to determine a diagnosis.
- Radiation oncologists who specialize in cancer treatment with radiation therapy.
What are common cancer treatments? Cancer treatments vary based on your cancer type, how far your cancer has progressed, and your overall health. Your oncologist may use one or more of the following common cancer treatments:
What do all these cancer terms mean? You want to understand all you can. Use our helpful glossary to understand common terms related to cancer.