General Cancer Information
Cancer is not one disease, but many diseases that occur in different areas of the body. Each type of cancer is characterized by the uncontrolled growth of cells. Under normal conditions, cell reproduction is carefully controlled by the body. However, these controls can malfunction, resulting in abnormal cell growth and the development of a lump, mass, or tumor. Some cancers involving the blood and blood-forming organs do not form tumors but circulate through other tissues where they grow.
A tumor can be benign (non-cancerous) or malignant (cancerous). Cells from cancerous tumors can spread throughout the body. This is called a metastasis. Metastasis or a mets occurs when cancer cells break away from the original tumor and travel through the blood stream or lymph system until they are lodged in another area of the body. Common locations of metastasis are the bones, lungs, liver, and brain.
The type of cancer refers to the organ or area of the body where the cancer first occurred. Cancer that has metastasized to other areas of the body is named for the part of the body where it originated. For example, if breast cancer has spread to the bones, it is called "metastatic breast cancer" not bone cancer. Often this is called a mets to the bone.
What causes cancer?
Our current understanding of what causes cancer is incomplete, but it is clear that cancer is not caused by an injury, such as a bump or bruise. Being infected with certain viruses may increase the risk of some types of cancer, but cancer is not contagious. No one can "catch" cancer from another person. Cancer develops gradually as a result of a complex mix of factors related to age, gender, environment, life style, and heredity. Scientists have identified many risk factors that increase the chance of getting cancer. They estimate that about 80% of all cancers are related to the use of tobacco products, to what we eat and drink, and, to a lesser extent, exposure to radiation or cancer causing agents (carcinogens) in the environment and the workplace. Some people are more sensitive than others to factors that can cause cancer.
Many risk factors can be avoided. Others, such as inherited risk factors, are unavoidable. It is helpful to be aware of them, but it is also important to keep in mind that not everyone with a particular risk factor for cancer actually gets the disease; in fact, most do not. Hereditary causes of cancer are rare and account for less than 5% of all cancer diagnoses. Some cancer is in the family or “familial”. This may be from the interaction of shared genes and shared lifestyle and environmental carcinogens.
How cancer is diagnosed
After a physical exam, the doctor will order various tests and exams. These may include imaging procedures such as CT, MRI or PET Scan, which produce pictures of areas inside the body; endoscopy, which allows the doctor to look directly inside certain organs; and laboratory tests. In most cases, the doctor may order a biopsy, a procedure in which a sample of tissue is removed. A pathologist examines the tissue under a microscope to check for cancer cells.
How is cancer treated?
Cancer is treated with surgery, radiation therapy, chemotherapy, hormone therapy, or biological therapy often call “targeted therapy”. Patients with cancer are often treated by a team of specialists, which may include a medical oncologist (specialist in medical cancer treatment), a surgeon, a radiation oncologist (specialist in radiation therapy), and others. The doctors may decide to use one treatment method or a combination of methods. The choice of treatment depends on the type and location of the cancer, the stage of the disease, the patient's age and general health, and other factors.
Learn more about treating cancer.