Cancer can affect anyone. Sometimes it strikes with no warning, while other times people may have a genetic predisposition. Various medical organizations say there are between 100 and 200 different types of cancer. Everyone has heard of cancer, but some are still unsure of what cancer is.
The organization Cancer Research UK defines cancer as abnormal cell growth. Cancer cells are cells that divide in an uncontrolled way. New human cells normally grow and divide to form new cells as the body requires them. As healthy cells grow old or become damaged, they die off and new cells take their place. However, when cancer develops, this process goes haywire. Damaged cells become even more abnormal and can survive when they would normally die. These cells keep multiplying and eventually can form lumps or masses of tissue called tumors. This is the case in most cancers, with the exception of leukemia, wherein cancer prohibits normal blood function due to abnormal cell division in the bloodstream.
Not all lumps in the body are tumors. Lumps that remain in place and do not spread to other areas of the body can be harmless or benign. According to the American Cancer Society, cancerous tumors are malignant, which means they can spread into, or invade, nearby tissues. Cancer stages actually are determined based by how far cancerous cells have spread beyond their point of origin.
Cancer is staged according to particular criteria based on each individual type of cancer. Generally speaking, lower stages of cancer, such as stage 1 or 2, refer to cancers that have not spread very far. Higher stages of cancer, such as 3, mean cancer has branched out more. Stage 4 refers to cancer that has spread considerably.
Common forms of cancer
Cancer can occur just about anywhere in the body. Cancers of the breast, lung, colon, and prostate cancers affect males and females in high numbers.
Classifying cancer involves understanding where the cancer originated. Cancer Treatment Centers of America offers these classifications:
• Carcinomas begin in the skin or tissues that line the internal organs.
• Sarcomas develop in the bone, cartilage, fat, muscle or other connective tissues.
• Leukemia begins in the blood and bone marrow.
• Lymphomas start in the immune system.
• Central nervous system cancers develop in the brain and spinal cord.
Cancer is treated in various ways and depends on the cancer's stage, type and effects on the body. A person's age as well as his or her current health status also may play a role in treatment decisions made by both the patient and his or her medical team. Surgery may be conducted to remove a tumor, while chemotherapy employs chemicals to kill cancerous cells. Radiation therapy, which uses X-rays to direct radiation toward cancerous cells, is another potential cancer treatment. The side effects of each treatment vary, and there are ways to mitigate these effects.
Why does cancer occur?
Cancer develops for various reasons — some of which may not be fully understood. The National Cancer Institute states genetic changes that cause cancer can be inherited from a person's parents. Cancers can also arise during a person's lifetime as a result of errors that occur as cells divide or because of damage to DNA that results from certain environmental exposures. Cancer-causing substances include the chemicals in tobacco smoke. Ultraviolet rays from the sun also have been linked to cancer.
Learning more about cancer can help people reduce their risk for developing this potentially deadly disease. Individuals should always speak with their physicians if they have specific questions about cancer.