Types of Cancer
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 the cancer cells get into the bloodstream or lymph vessels of our body. When cells from a cancer like breast cancer spread to another organ like the liver, the cancer is still called breast cancer, not liver cancer.
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 environment, like smoking.
Cancer usually forms as a 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 other parts of the body (metastasize) and, with very rare exceptions, are not life-threatening.
Different types of cancer can behave very differently. For example, lung cancer and breast cancer are very different diseases. 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 quitting smoking and eating a better diet. The sooner a cancer is found and treatment begins, the better are the chances for living for many years.
You may want to visit sites from the American Society of Clinical Oncologists (ASCO) and the National Cancer Institute (NCI), which include alphabetical lists of many types of cancers. Clicking on the name of the type of cancer on which you are seeking information will take you to specific information about that cancer.
Understanding Breast Cancer
Understanding Colorectal Cancer
Understanding Lung Cancer
Understanding Prostate Cancer
Cancer Care Information Guides
Developments in Fighting Breast Cancer
Advances in Fighting Colorectal Cancer
Treating Head & Neck Cancer
Treating Kidney Cancer
Coping with Lung Cancer
Caring for Your Bones with Lung Cancer
Bone Health with Multiple Myeloma
Bone Health for Prostate Cancer Patients
Treating Prostate Cancer with Radiation
American Society of Clinical Oncology (ASCO) Information Guides
Bisphosphonates in the Treatment of Breast Cancer
Follow-Up Care for Breast Cancer
Chemotherapy for Stage III Colon Cancer
Follow-Up Care for Colorectal Cancer
Preserving the Layrnx During Cancer Treatment
Advanced Lung Cancer Treatment
Hormone Therapy for Prostate Cancer