Defining Cancer
Cancer is a collective term for diseases in which abnormal cells divide uncontrollably and can invade other tissues used. Cancer cells to other parts of the body by the blood and lymphatic spread.
Cancer is not just one disease but many diseases. There are over 100 different types of cancer. Most cancers are for the organ or type of cell in which they start - for example, mentioned that cancer begins in the colon is called colon cancer, cancer that begins in basal cells of the skin, called basal cell carcinoma.
Cancers can be grouped into larger 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 in bone, cartilage, fat, muscle, blood vessels, connective tissue or others, or supporting tissue begins.
Leukemia - cancer that starts in blood-forming tissue such as the bone marrow to produce and maintain a large number of abnormal blood cells and enter the blood.
Lymphoma and myeloma - cancers that begin in the cells of the immune system.
Central nervous system cancers - tumors that begin in the tissues of the brain and spinal cord.
(For definitions of other cancer-related terms, see the NCI's Dictionary of Cancer Terms.)
="">All cancers begin in cells, the body's basic unit of life. to understand cancer, it hilfreichzu know what happens when normal cells become cancer cells.
The body consists of many types of cells. These cells grow and divide in a controlled way to produce more cells as they are required to keep the body healthy. When old or damaged cells, they die and are replaced by new cells.
But sometimes orderly process goes wrong. The genetic material (DNA) of a cell can be damaged or altered, mutations that produce normal cell growth and affect distribution. If this happens, the cells do not die when they should and to form new cells when the body does not need it. The extra cells form a mass of tissue called a tumor.
(Image from the series understanding of cancer: cancer.)
Not all tumors are cancerous, tumors can be benign or malignant.
Benign tumors are not cancerous. Can often be removed, and, in most cases they do not come back. Cells in benign tumors have not spread to other parts of the body.
Malignant tumors are malignant. can penetrate cells in these tumors nearby tissue and spread to other parts of Kbody. The spread of cancer from one part of the body to another called metastases.
Some cancers do not form tumors. For example, leukemia is a cancer of the bone marrow and blood.
Cancer Statistics
A new report by the country's leading cancer organizations shows that, for the first time since the first report in 1998, offered ausgestellth incidence and mortality for all cancers combined for both men and women decreases, driven largely by declines in some of the most common types of cancer. (Read about the annual report.)
Estimated new cases and deaths from cancer in the United States in 2009:
New cases: 1,479,350 (does not include nonmelanoma skin cancer)
Deaths: 562 340
NCI's Cancer Stat Fact Sheets frequently offer cancer statistics for a number of cancers requested.
