General Cancer Information

Screening & Detection

Sometimes, cancer can be found before the disease causes symptoms. Checking for cancer (or for conditions that may lead to cancer) in a person who does not have any symptoms of the disease is called screening.

In routine physical exams, the doctor looks for anything unusual and feels for any lumps or growths. Specific screening tests, such as lab tests, x-rays, or other procedures, are used routinely for only a few types of cancer.

Breast

A screening mammogram is the best tool available to find breast cancer before symptoms appear. A mammogram is a special kind of x-ray image of the breasts. Breast cancer screening has been shown to reduce the risk of dying from this disease. The National Cancer Institute recommends that women in their forties and older have mammograms on a regular basis, every one to two years.

Cervix

Doctors use the Pap test, or Pap smear, to screen for cancer of the cervix. For this test, cells are collected from the cervix. The cells are examined under a microscope to detect cancer or changes that may lead to cancer.

Colon and Rectum

A number of screening tests are used to find colon and rectal (colorectal) cancer. If a person is over the age of 50 years, has a family medical history of colorectal cancer, or has any other risk factors for colorectal cancer, a doctor may suggest one or more of these tests.

Sometimes tumors in the colon or rectum can bleed. The fecal occult blood test checks for small amounts of blood in the stool.

The doctor sometimes uses a thin, lighted tube called a sigmoidoscope to examine the rectum and lower colon. Or, to examine the entire colon and rectum, a lighted instrument called a colonoscope is used. If abnormal areas are seen, tissue can be removed and examined under a microscope.

A barium enema is a series of x-rays of the colon and rectum. The patient is given an enema with a solution that contains barium, which outlines the colon and rectum on the x-rays.

A digital rectal exam is an exam in which the doctor inserts a lubricated, gloved finger into the rectum to feel for abnormal areas.

Although it is not certain that screening for other cancers actually saves lives, doctors also may suggest screening for cancers of the skin, lung, and oral cavity. And doctors may offer to screen men for prostate or testicular cancer, and women for ovarian cancer.

Doctors consider many factors before recommending a screening test. They weigh factors related to the individual, the test, and the cancer that the test is intended to detect. For example, doctors take into account the person's age, medical history and general health, family history and lifestyle. The doctor pays special attention to a person's risk for developing specific types of cancer. In addition, the doctor will assess the accuracy and the risks of the screening test and any follow-up tests that may be necessary. Doctors also consider the effectiveness and side effects of the treatment that will be needed if cancer is found.

People may want to discuss any concerns or questions they have about screening with their doctors, so they can weigh the pros and cons and make informed decisions about having screening tests.