Cancer is the general name for a large group of diseases. It occurs when cells in the body grow and divide out of control.Our bodies are made up of millions of cells. Layers of cells form tissues. Normal cells grow, divide, and die in an orderly way. This process helps keep our bodies healthy.
Cancer cells grow and divide too quickly. The process usually starts when something damages the genetic structure (DNA) inside the cells. Instead of dying in an orderly way, cancer cells keep growing, lump together and form an extra mass of tissue. This mass is called a malignant tumor. As a malignant tumor grows, it damages nearby tissue. A malignant tumor can take a long time (up to 30 years) or a short time (2 or 3 years) to cause symptoms.
Cancer can begin in one part of the body and spread to other parts. This is called metastasis (me-tas-ta-ses). During metastasis, cancer cells travel through the body. In the new location, cancer cells create a new malignant tumor and grow out of control.
Not all tumors are malignant. Some are benign, which means they aren’t cancerous. Benign tumors usually aren’t life threatening. They can usually be removed and rarely come back.
Since, cancer is the uncontrolled growth of the cells as a result of mutation- i.e. alteration of the DNA, resulting in the cell losing its ability to function in a disciplined manner.This undisciplined, disorganized, uncontrolled, growth of the cancer cells causes the destruction of healthy cells, and eventually death of the affected person. What causes alteration of the cell’s DNA? The cells are affected by what is known as carcinogens.