Cancer is a term used for diseases in which abnormal cells divide without control and are able to invade other tissues. Cancer cells can spread to other parts of the body through the blood and lymph systems.
The body is made up of a variety of different types of cells. These cells grow and divide in a controlled way to produce more cells as they are needed to keep the body healthy. When cells become old or damaged, they die and are replaced with new cells. But sometimes this process goes wrong: the genetic material (DNA) of a cell can become damaged or altered, producing mutations that affect normal cell growth and division. When this happens, cells do not die when they should and new cells form when the body does not need them. The extra cells may form a mass of tissue called a tumor.

Not all tumors are cancerous; tumors can be benign or malignant:
Benign tumors aren't cancerous. They can often be removed, and, in most cases, they do not come back. Cells in benign tumors do not spread to other parts of the body.
Malignant tumors are cancerous. Cells in these tumors can invade nearby tissues and spread to other parts of the body. The spread of cancer from one part of the body to another is called metastasis.
Some cancers do not form tumors. For example, leukemia is a cancer of the bone marrow and blood.

Types of Cancer
Cancer types can be grouped into broader categories. The main categories of cancer include:

• Carcinoma - cancer that begins in the skin or in tissues that line or cover internal organs.
• Sarcoma - cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.
• Leukemia - cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of abnormal blood cells to be produced and enter the blood.
• Lymphoma and myeloma - cancers that begin in the cells of the immune system.
• Central nervous system cancers - cancers that begin in the tissues of the brain and spinal cord.

^ Back to Top

Cancer Treatment
Most cancers can be treated and some cured, depending on the specific type, location, and stage. Once diagnosed, cancer is usually treated with a combination of surgery, chemotherapy and radiotherapy. As research develops, treatments are becoming more specific for different varieties of cancer. There has been significant progress in the development of targeted therapy drugs that act specifically on detectable molecular abnormalities in certain tumors, and which minimize damage to normal cells. The prognosis of cancer patients is most influenced by the type of cancer, as well as the stage, or extent of the disease. In addition, histologic grading and the presence of specific molecular markers can also be useful in establishing prognosis, as well as in determining individual treatments.

^ Back to Top

Cancer has a reputation for being a deadly disease. While this certainly applies to certain particular types, the truths behind the historical connotations of cancer are increasingly being overturned by advances in medical care. Some types of cancer have a prognosis that is substantially better than nonmalignant diseases such as heart failure and stroke. Progressive and disseminated malignant disease has a substantial impact on a cancer patient's quality of life, and many cancer treatments (such as chemotherapy) may have severe side-effects. In the advanced stages of cancer, many patients need extensive care, affecting family members and friends. Palliative care solutions may include permanent or "respite" hospice nursing.

---

This healthcare portal website has been created as a source of objective and credible health and medical information for healthcare professionals and consumers and does not endorse any specific product, service or organization. MEDIVISION does not warrant the accuracy of this information, and it is intended as a supplement to, and NOT a substitute for, the knowledge, skill, and judgment of healthcare professionals. If you have questions about health care, please consult a physician or other health care professional.
COPYRIGHT © MEDIVISION, 2011