Cancer: What is it?

what is cancer

Over their lifetimes, one in every two American men and one in three American women will get cancer.

Cancer is a general term for more than 100 diseases caused by uncontrolled, abnormal cell growth and death. The four most common cancers affect the breasts, colon or rectum, lungs and prostate.

Abnormal cell growth

Healthy cells that make up body tissues grow, divide and replace themselves in an orderly way. But sometimes cells lose their ability to limit and direct their growth. Too much tissue forms and tumors develop.

  • Benign tumors are not cancer. They do not spread and rarely threaten life.
  • Pre malignant tumors have a risk of developing into cancer.
  • Malignant tumors are cancer. They can spread, or metastasize, to other parts of the body. Cancer cells harm the body by depriving normal, healthy cells of nourishment and space.

Early detection and treatment can prevent cancer from spreading.

Early cancer symptoms

Anyone can get cancer, especially if someone in your family has had it.

Cancer is not one disease and its symptoms, treatment and outlook depend on the organ it affects. The earlier cancer is spotted, the more likely it can be stopped. That is why it's important to watch for these warning signs:

  • an obvious change in a wart or mole on the skin
  • a sore that does not heal
  • a chronic, nagging cough or hoarseness
  • a change in bladder or bowel habits
  • a lump or thickening in the breast or elsewhere in the body
  • chronic indigestion or difficulty swallowing
  • unusual bleeding or bruising
  • unusual discharge from any body opening

If you notice any one of those symptoms, have it checked out by a doctor as soon as possible.

What if it's cancer?

Years ago, a diagnosis of cancer almost always meant death. But continuing advances in detection and treatment have made cancer a chronic illness that may be stopped, even cured.

Nonetheless, a cancer diagnosis often comes as a shock. Knowledge and support can help you deal with the reality.

  • Knowledge about your condition can help you feel more in control.
    • Find a cancer resource center in your area.
    • Call hotlines like the Cancer Information Service at 1-800-4-CANCER.
    • Search the Internet for resources like the American Cancer Society.
    • Talk with your doctor. Let your doctor know how much you want to know and how you process information. Do you like diagrams or videos? Would you like to talk to someone with the same cancer? Do you want another opinion?
  • Support makes a big difference in how you cope with cancer. Usually, family and friends are there for you, but sometimes it isn't possible or enough.
    • Cancer support groups can connect you with people who are dealing with or have overcome cancer.
    • Spiritual leaders, such as a hospital chaplain, pastor or rabbi, can help as well.

Source: American Cancer Society, Cancer Statistics 2009 Presentation; National Cancer Institute
Reviewed By: Timothy Sielaff, MD, PhD, FACS, president, Virginia Piper Cancer Institute®
First Published: 04/01/2004
Last Reviewed: 08/17/2009