Understanding Cancer

Understanding Cancer

Cancer is a complex and varied disease. It can begin anywhere in the body and spread for reasons that are not yet understood. Even the same kind of cancer behaves differently from one patient to the next.

Defining Cancer

The National Cancer Institute defines cancer as the following:
Cancer is a term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems.

There are several main types of cancer:

  • Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs.
  • Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.
  • Leukemia is a cancer that starts in blood-forming tissue, such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood.
  • Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system.
  • Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

What Causes Cancer?

It is unknown what exactly what causes cancer. Cancer development can be hereditary or it could be caused by certain factors like tobacco, diet or too much sun exposure.

Because of the lack of knowledge regarding the cause of cancer, many patients start to question what they did wrong and blame themselves. It is important to know that it is not your fault and cancer is not a punishment for your actions. If you are unsure what caused your cancer or have questions, talk to your health care provider.


Cancer symptoms vary from person to person and from cancer to cancer. Some people may experience extreme fatigue, pain that is not improving or new growths on their skin or other body parts. Other people may have a cancer that shows no signs or symptoms.

Cancer can be diagnosed through lab tests, imaging procedures and biopsies.


Doctors can better decide a course of treatment when they know the stage of a cancer. The cancer stage determines if and how far the cancer has spread from its point of origin. There are tests to be done for every type of cancer to figure out the stage of cancer.

Typically, the lower stages (stage 1 or 2) means the cancer has not spread much. The higher stages (stage 3 or 4) means it has spread more.

Risk Factors

Below is a list of the most-studied known or suspected risk factors of cancer:

  • Age
  • Alcohol
  • Cancer-causing substances
  • Diet
  • Hormones
  • Immunosuppression
  • Infectious agents
  • Obesity
  • Radiation
  • Sunlight
  • Tobacco

Common Cancer Words

After diagnosis, patients will hear a variety of medical terms that may be foreign to them. The following is a list provided by the American Cancer Society of common cancer words:

  • Benign: a tumor that is not cancer
  • Biopsy: taking out a piece of tissue to see if cancer cells are in it
  • Cancer: a word used to describe more than 100 diseases in which cells grow out of control; or a tumor with cancer in it
  • Chemotherapy: the use of drugs to treat disease. The word most often refers to drugs used to treat cancer. Sometimes it’s just called “chemo.”
  • Malignant: having cancer in it
  • Metastasis/Metastasized: the spread of cancer cells to distant parts of the body through the lymph system or bloodstream
  • Oncologist: a doctor who treats people who have cancer
  • Radiation therapy: the use of high-energy rays, like x-rays, to treat cancer
  • Remission: when signs or symptoms of cancer are all or partly gone
  • Stage: a word that tells whether a cancer has spread, and if so, how far