37TAB THREE | UNDERSTANDING CANCER patient guide
Screening Some types of cancer can be found before they cause symptoms. Checking for cancer (or for conditions that may lead
to cancer) in people who have no symptoms is called screening.
Screening can help doctors find and treat some types of cancer early. Generally, cancer treatment is more effective when
the disease is found early.
Screening tests are used widely to check for cancers of the breast, cervix, colon and rectum:
Breast: A mammogram is the best tool doctors have to find breast cancer early. A mammogram is a picture of the breast made with x-rays. The NCI recommends that women in their 40s and older have mammograms every one to two years.
Women who are at higher-than-average risk of breast cancer should talk with their health care provider about whether to
have mammograms before age 40 and how often to have them.
Cervix: The Pap test (sometimes called Pap smear) is used to check cells from the cervix. The doctor scrapes a sample of cells from the cervix. A lab checks the cells for cancer or changes that may lead to cancer (including changes caused
by human papillomavirus, the most important risk factor for cancer of the cervix). Women should begin having Pap tests
three years after they begin having sexual intercourse, or when they reach age 21 (whichever comes first). Most women
should have a Pap test at least once every three years.
Colon and rectum: A number of screening tests are used to detect polyps (growths), cancer or other problems in the colon and rectum. People aged 50 and older should be screened. People who have a higher-than-average risk of cancer
of the colon or rectum should talk with their doctor about whether to have screening tests before age 50 and how often
to have them.
• Fecal occult blood test: Sometimes cancer or polyps bleed. This test can detect tiny
amounts of blood in the stool.
• Sigmoidoscopy: The doctor checks inside the rectum and lower part of the colon with
a lighted tube called a sigmoidoscope. The doctor can usually remove polyps through
the tube.
• Colonoscopy: The doctor examines inside the rectum and entire colon using a long,
lighted tube called a colonoscope. The doctor can usually remove polyps through the tube.
• Double-contrast barium enema: This procedure involves several x-rays of the colon and
rectum. The patient is given an enema with a barium solution, and air is pumped into
the rectum. The barium and air improve the x-ray images of the colon and rectum.
• Digital rectal exam: A rectal exam is often part of a routine physical exam. The health
care provider inserts a lubricated, gloved finger into the rectum to feel for abnormal
areas. A digital rectal exam allows for examination of only the lowest part of the rectum.
Prostate: Men should make an informed decision with their doctor about whether to be tested for prostate cancer.
Research has not yet proven that the potential benefits of testing outweigh the harms of testing and treatment. Men
should not be tested without learning about what we know and don’t know about the risks and possible benefits of testing
