Cells and tissues of the body continues to function in balance. There are now split, grow and be destroyed and then discarded. Cell or tissue in carrying out its functions can be impaired balance. One of the imbalances that can occur is the existence of a cell or tissue which grow wild and unbiased self-controlled and double grows, so grows the network or abnormal cells called tumors. There are two kinds of tumors:
- Benign tumors
Tumors that are not harmful not only to grow bigger and spread out its network.
- Tumor dangerous
Very different dangerous tumor, called cancer. Cancer is a cell that has lost control and normal mekasime so unnatural growth, wild and often spread far into other tissue cells and damage.
Cancer can occur in various tissues in various orrrgan every body, from feet to head. Cancer cells can be derived from all the elements that make up an organ. In line with its growth, cancer cells form a mass of tissue that infiltrated berbahya nearby tissue or bias spread (metastasize) to other organs.
Into cancer cells through a complex process called transformation. Cancer initially undergo a process of initiation, in which the genetic material change, which will be kenker. Changes can be spontaneous or caused by an element (agent) called the substance a carcinogen. Carcinogenic substances can be chemicals, certain foods (tobacco), viruses, radiation and ultraviolet light, and because factor of mental (psychic).
Genesis for certain types of cancer has indeed been altered. In this case the earlier cancer is often found now become rare.
Age is an important factor in the occurrence of cancer. Some cancers are influenced by age, such as Wilms' tumor, acute leukemia and lymphoma Burkitt lomfositik often attack people who are younger. The cause is uncertain, but one factor that plays quite important is the tendency of offspring (genetic).
But in general, most cancers occur in elderly. Prostate cancer, stomach and colon, most likely to occur after age 60 years (possibility of more than 60%). The increased incidence of cancer may be a combination of increased and increasing duration of exposure to cancer-causing substances (carcinogens) and a weak or declining immune system, particularly T cells and white blood.