What causes cancer ? This is the Causes of Cancer which must We know.

     What causes cancer? In previous posts we have discussed about what is cancer? Cancer is cells that have lost normal control mechanisms, so the growth is irregular. Cancer can occur from a variety of tissues in various organs. In line with the growth and breeding, cancer cells form a mass of malignant tissue to infiltrate nearby tissues and can spread (metastasize) throughout the body. Established cancer cells from normal cells in a complicated process called transformation, which consists of initiation and promotion stages.

      At the initiation stage occurs a change in the genetic material of cells into malignant cells fishing. Changes in the genetic material of cells is caused by an agency called carcinogens, which could be chemicals, viruses, radiation (irradiation) or the sun. But not all cells have the same sensitivity to a carcinogen. Genetic abnormalities in cells or other substances, called promoters, causing the cells more susceptible to a carcinogen. Even physical impairments can make cells more sensitive menahunpun to have malignancy.

      At the stage of promotion, a cell that has undergone initiation will become malignant. Cells that have not passed the stage of initiation is not affected by the campaign. Because it takes several factors to the occurrence of malignancies (combination of a sensitive cell and a carcinogen).

      In a process in which normal cells into malignant cells, eventually DNA from these cells will change. Changes in the cell's genetic material is often difficult to find, but sometimes the cancer can be detected by the presence of a change in size or shape of a particular chromosome. For example, an abnormal chromosome called the Philadelphia chromosome is found in approximately 80% of patients with chronic leukemia mielositik. Genetic changes have also been found in brain tumors and colon cancer, breast, lung and bone.

      It may take a series of chromosomal changes in cancer occurrence. Research on family polyposis colon (bowel disorder hereditary form of the growth of polyps that turn into malignant), has brought us to a suspicion of how this occurs in colon cancer. The normal lining of the colon begin to grow actively (hyperproliferation), because their cells no longer have a suppressor gene on chromosome 5, which normally control the growth of the layer. Further changes in the small DNA facilitates the formation of adenoma (benign tumor). Other genes (oncogenes RAS) causes adenomas to grow more active. The loss of suppressor genes on chromosome 18 will further stimulate adenoma and ultimately the loss of genes on chromosome 17 would change the benign adenoma to cancer. Additional changes can cause cancer to spread throughout the body (metastases).

      When a cell becomes malignant, the immune system often can destroy malignant cells before multiply and become cancerous. Cancer tends to occur when the immune system does not function normally, as was the case in humans. AIDS, people who are using immunosuppressant drugs and in certain autoimmune diseases. 

      But not always effective immune system, cancer can penetrate this protection even if the immune system to function normally.