by Gen
Cancer develops when cells in a part of the body begin to grow out of control. Although there are many kinds of cancer, they all start because of out of control growth of abnormal cells.
Normal body cells grow, divide and die in an orderly fashion. During the early years of a person's life, normal cells divide more rapidly until the person becomes an adult. After that, cells in most parts of the body divide only to replace worn out or dying cells and to repair injuries.
Because cancer cells continue to grow and divide, they are different from normal cells. Instead of dying, they outlive normal cells and continue to form new abnormal cells.
Cancer cells often travel to other parts of the body where they begin to grow and replace normal tissue. This process, called metastasis, occurs as cancer cells get into the bloodstream or lymph vessels of our body.
Cancer cells develop because of damage to DNA. This substance is in every cell and directs all its activities. Most of the time when DNA becomes damaged the body is able to repair it. In cancer cells, the damaged DNA is not repaired. People can inherit damaged DNA, which accounts for inherited cancers. Many times though, a person's DNA becomes damaged by exposure to something in the enviroment, like smoking.
Cancer usually forms as a solid tumor. Some cancers, like leukemia, do not form tumors. Instead, these cancer cells involve the blood and blood forming organs and circulate through other tissues where they grow.
Not all tumors are cancerous. Benign (noncancerous) tumors do not spread to the other parts of the body (metastasize) and, with very rare exceptions, are not life threatening.
Different types of cancer can behave very differently. They grow at different rates and respond to different treatments. That is why people with cancer need treatment that is aimed at their particular kind of cancer.
Cancer is the second leading cause of death in the United States. Half of all men and one third of all women in the US will develop cancer during their lifetimes. Today, millions of people are living with cancer or have had cancer. The risk of developing most types of cancer can be reduced by changes in a person's lifestyle, for example, by quiting smoking and eating a better diet. The sooner a cancer s found and treatment begins, the better are the chances for living for many years.
Over one million people get cancer each year. Approximately one out of every two American men and one out of every three American women will have some type of cancer at some point during their lifetime. Anyone can get cancer at any age; however, about 77% of all cancer occurs in Americans of all racial and ethnic group, the rate of cancer occurence (called the incidence rate) varies from group to group.
Today, millions of people are living with cancer or have been cured of the disease. The sooner a cancer is found the better a patient's chances are of a cure. That's why early detection of cancer is such an important weapon in the fight against cancer.
A risk factor is anything that increases a person's chance of getting a disease. Some risk factors can be changed, and others cannot. Risk factors for cancer can include a person's age, gender, and family medical history. Others are linked to cancer-causing factors in the enviroment.
