Cancer is a disease in which abnormal cells begin to grow, divide and spread within the body, causing a variety of complications over time. There are hundreds of types of cancer, affecting virtually every part of the body.
Cancer is one of the leading causes of death among Americans. However, the death rate from cancer has been steadily declining.
Types of Cancer
Of the many forms of cancer, some of the most common include sarcoma, carcinoma, leukemia, lymphoma, myeloma and central nervous system cancers. Carcinomas are tumors that grow in tissues that line internal organs, whereas sarcomas appear in fat, muscle, bone or other supportive tissues. Leukemia, lymphomas and myeloma all affect the blood and the immune system, and central nervous system cancers affect the brain and spinal cord.
Causes of Cancer
Cancer causes come in all shapes, sizes and varieties, and researchers are still learning about the true roots of many forms of cancer. In some instances, such as a strong family history of the disease, the cause of a form of cancer may be totally out of your control. But other risk factors, such as smoking or sun exposure, can be managed. Additional risk factors for cancer can include poor diet, alcohol consumption, other diseases leading to cancer and simply growing older.
Once cancer starts, it usually has a tendency to grow and spread throughout the body. This process is called metastasis. Regardless of where it spreads, however, the cancer is always named after the part of the body where the original cancerous cells or tumors grew.
There are a variety of treatment possibilities for cancer. Often, the first step is surgery to remove the cancerous cells or tumor from the body. Typically, a form of therapy to kill cancer cells in surrounding tissue is also needed. This comes in the form of radiation therapy or chemotherapy. Biological therapy, hormone therapy, targeted therapy and stem cell transplantation are other forms of treatment that are sometimes used to treat cancer.
SOURCES: U.S. National Cancer Institute; American Cancer Society
Cancer deaths in U.S. steadily decline over 25-year period.