The definition of cancer is a group of diseases caused by abnormal cells dividing without control. These cells can invade nearby tissues and also spread to other parts of the body through the bloodstream and lymphatic system.

The Greek physician Hippocrates, known as the “father of medicine,” used the term karkinos, which means “crab,” to describe tumors. There are several theories why he chose this name: the hard texture of tumors reminded him of a crab shell, a tumor and its finger-like projections looked like a crab’s body, the pain of a tumor was like being pinched by a crab, or the difficulty in getting rid of a tumor was similar to a crab refusing to let go. Later, the Roman physician Celsus translated the term into the Latin word for crab, which is cancer.

Cancers are named after the area where they start (even if they move to other areas) and the type of cell they’re made of. The top five most common cancer types are breast cancer, lung cancer, prostate cancer, colorectal cancer and melanoma skin cancer. There are also medical terms for the general types of cancer: carcinoma, which is cancer of the skin or tissues that line other organs; sarcoma, which is cancer of connective tissues like blood vessels and muscle; leukemia, which is cancer of the bone marrow; lymphoma, which is cancer of the lymphatic system; and myeloma, which is cancer of specific white blood cells called plasma cells.

Our experts are researching over two dozen cancers, including:

Mutations to cellular DNA cause cancer. A cell’s DNA has instructions about how to grow and divide; when there’s an error in those instructions, the cell could grow more rapidly, fail to stop uncontrolled growth or make mistakes when repairing DNA. Cancer can be genetic if you have a mutation you inherited from your parents, but this is only true in a small percentage of cases. Genes can also mutate due to outside forces, like smoking, radiation, chronic inflammation, hormones or lack of exercise. Signs of cancer are different depending on what area of the body is affected. Some general symptoms that can be associated with cancer include fatigue, a lump or thickened area under the skin, weight changes, trouble breathing, persistent indigestion, and persistent muscle or joint pain.

Today, there are many available ways to treat cancer; the type of cancer and the goal of treatment will determine which method or combination of methods is right for a patient. Doctors use surgery to remove as much of the cancer as possible. Chemotherapy uses medication to kill cancer cells. Radiation therapy uses energy beams like X-rays to kill cancer cells. The radiation can come from a machine or be placed inside the body. Immunotherapy boosts the immune system to attack cancer cells. Hormone therapy can help check the growth of certain types of cancer that are affected by hormones.