In line with the growth and development, cancer cells form a mass of malignant tissue to infiltrate nearby tissue (invasive) and spread (metastasis) to the entire body. Formed cancer cells from normal cells in a complex process called transformation, which consists of initiation and promotional phase.
At the initiation phase, there was a change in the genetic material of cells caused by an agent called a carcinogen, which can include chemicals, viruses, radiation (radiation), or sunlight. However, 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 chronic physical disorders can make the cells become more sensitive to having a malignancy.
In the promotion phase, a cell that has undergone the initiation will become malignant. Cells that have not passed the initiation stage will not be affected by the campaign. Therefore, it may take several factors yantuk occurrence of malignancies (combination of sensitive cells and a carcinogen).
When a cell becomes malignant, the immune system can often spoil before these malignant cells multiply and become a cancer. However, if the immune system does not operate normally, the body vulnerable to cancer risk, as happens in people with AIDS, people who use immunosuppressive drugs, and in certain autoimmune diseases. However, the immune system are not always effective, so that sometimes cancer can still penetrate this protection even if the immune system function normally.
