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Learn About Cancer

Cancer Basics

Cancer does not discriminate when it comes to race, sex, or age. Anyone can get cancer.

Cancer develops from a single cell that has undergone mutations in its DNA, the genetic material that carries the body's hereditary instructions. Most often the reason for these mutations the are unknown. Normal, healthy cells in your body grow in a very orderly and well-controlled pattern, living for a set period of time and then dying when they are no longer able to perform their function.

When a normal cell dies, your body replaces it with another normal cell. Cancerous cells reproduce without restraint, or become malignant.

cancer patient with nurseMalignant definition: Cancer cells continuously divide, one malignant cell becomes two, two become four, four become eight, and so on.  This process is known as doubling time.  This process continues until a mass of cells (a tumor) is created. Tumors remain small until they are able to attract their own blood supply, which allows them to obtain the oxygen and nutrients they need to grow larger.

Not all tumors are cancerous and not all cancers form tumors. For example, leukemia is a cancer that involves blood, bone marrow, the lymphatic system, and the spleen, but does not form a single mass or tumor.

Cancer can also spread (metastasize) and invade healthy tissue in other areas of your body.

Cancer can take many years to develop. By the time a cancerous mass is detected, it is likely that 100 million to 1 billion cancer cells are present, and the original cancer may have been dividing for five years or more.

The only way to diagnose cancer is to examine the cells under a microscope. Imaging tests, such as computerized tomography (CT) or mammography, can indicate the possible presence of cancer by showing an abnormal mass, but cancer can only be definitively diagnosed by looking closely at the cancer cells under a microscope.

Doctors use a surgical process called a biopsy to obtain a sample of suspicious tissue.

Under the microscope, normal cells look uniform, with similar sizes. Cancer cells look less orderly, with varying sizes.