Cancer is an umbrella term for a large gr oup of diseases caused when abnormal cells divide rapidly, and spread to other tissue and organs. Cancer is one of the leading causes of death in the world.
In a healthy body, the trillions of cells it’s made of grow and divide, as the body needs them to function daily. Healthy cells have a specific life cycle, reproducing and dying off in a way that is determined by the type of cell. New cells take the place of old or damaged cells as they die. Cancer disrupts this process and leads to abnormal growth in cells. It’s caused by changes or mutations in DNA.
DNA exists in the individual genes of every cell. It has instructions that tell the cell what functions to perform and how to grow and divide. Mutations occur frequently in DNA, but usually cells correct these mistakes. When a mistake is not corrected, a cell can become cancerous.
Mutations can cause cells that should be replaced to survive instead of die, and new cells to form when they’re not needed. These extra cells can divide uncontrollably, causing growths called tumors to form. Tumors can cause a variety of health problems, depending on where they grow in the body.
But not all tumors are cancerous. Benign tumors are noncancerous and do not spread to nearby tissues. Sometimes, they can grow large and cause problems when they press against neighboring organs and tissue. Malignant tumors are cancerous and can invade other parts of the body.
Some cancer cells can also migrate through the bloodstream or lymphatic system to distant areas of the body. This process is called metastasis. Cancers that have metastasized are considered more advanced than those that have not. Metastatic cancers tend to be harder to treat and more fatal.
Cancers are named for the area in which they begin and the type of cell they are made of, even if they spread to other parts of the body. For example, a cancer that begins in the lungs and spreads to the liver is still called lung cancer. There are also several clinical terms used for certain general types of cancer:
The direct cause of cancer is changes (or mutations) to the DNA in your cells. Genetic mutations can be inherited. They can also occur after birth as a result of environmental forces. Some of these forces include:
Cancer risk tends to increase with age. Some existing health conditions that cause inflammation may also increase your risk of cancer. An example is ulcerative colitis, a chronic inflammatory bowel disease.
Knowing the factors that contribute to cancer can help you live a lifestyle that decreases your cancer risks. According to experts, these are the seven best ways to prevent cancer:
Visit the Cancer Prevention section for more information »
Cancer treatment has different objectives, depending on the type of cancer and how advanced it is. These objectives include:
The most common types of treatment are:
Surgically removes as much of the cancer as possible.
Uses medications that are toxic to cells to kill rapidly-dividing cancer cells.
Uses powerful, focused beams of radiation inside (brachytherapy) or outside (external beam radiation) your body to kill cancer cells.
Repairs diseased bone marrow with healthy stem cells. Stem cells are undifferentiated cells that can have a variety of functions. These transplants allow doctors to use higher doses of chemotherapy to treat the cancer.
Uses antibodies to help your body’s immune system recognize cancer so it can fight it off.
Hormone Therapy
Removes or blocks hormones that fuel certain cancers to stop cancer cells from growing.
Uses drugs to interfere with certain molecules that help cancer cells grow and survive.
Investigates new ways to treat cancer.
Used to decrease symptoms of cancer and side effects of cancer treatment, such as nausea, fatigue, and pain. Alternative medicine includes: