Occurrence Cause Cancer

How Cancer Event

Cancer is cells that have lost normal control mechanisms, so that the irregular growth. Cancer can occur from various tissues in various organs. In line with the growth and breeding, cancer cells form a mass of malignant tissue that infiltrate into nearby tissues and can spread (metastasize) throughout the body.

Cancer cells are formed from normal cells in a complex process called transformation, which consists of initiation and promotion stage.

At the initiation stage occurs a change in the genetic material of cells that provoke the cells become malignant. Change in the cell's genetic material is is caused by an agency called carcinogens, which can include chemical, viruses, radiation (irradiation) or sunlight.

But not all cells have the same sensitivity to a carcinogen. Genetic abnormalities in cells or other material which is called the promoter, causing the cells more susceptible to a carcinogen. Even chronic physical disoders can make the cells become more sensitive to having a malignancy.

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

In a process in which a normal cell into a malignant cell, in the end the DNA of those cells will change. Changed in the cell's genetic material is often hard to find, but the occurrence of cancer can sometimes be know from the existence of a change in size or shape of particular chromosome.

For example, an abnormal chromosome. called the Philadelphia Chromosome found in sbout 80% of patients with chronic leukemia mielositik. The genetic change have also been found in brain tumors andd colon cancer, breast, lung and bone.

It may take a series of chromosomal changes to the occurrence of cancer. Research on familial polyposis of the colon (bowel disorder hereditary form of growth that turned into a malignant polyp), has brought as to a nation how this accurs. The normal lining of the colon begin to growth actively  (hiperproliferasi), because the cells no longer have the suppressor gene on chromosome  5 that under normal circumstances  to control the growth of these  layers.

Furthermore, mild changes in DNA facilitate the formation of adenomas (benign tumors). Other genes (oncogenes RAS) causes adenoma grows more active.

Loss of suppressor genes on chromosome 28 will further stimulate adenoma and ultimately the loss of genes on Chromosome 18 will further stimulate adenoma and ultimately the loss of genes on chromosome 17 would change the benign adenoma into cancer. Other additional changes can use cancer spread throughout the body (metastasis).

When a cell becomes malignant, the immune system can often spoil before these malignant cells multioly and become a cancer.

Cancers tends to occur if the immune system does not function normall, as happens in people. AIDS, people who use immune-suppressing drugs in certain autoimmune diseases. But now always effective  immune system, cancer can penetrate this protection even if the immune system to function normally.

Posted in: cancer