Cancer Screening

What is cancer screening?

Cancer screening refers to tests that can be done to look for signs of cancer or to see if you are likely to develop cancer. There are 2 types of cancer screening tests: early detection tests and preventive screening tests.

• Early detection tests look for cancer that already exists, trying to find it early. Mammograms are an example of an early detection test because they can find breast cancer when it is still really small.
• Preventive screening tests look for growths or cells that are likely to become cancer. Pap smears are an example of a preventive screening test. They can find precancerous cells before they become cancer and when they can still be removed so that the cancer never develops. Another example of a preventive screening test is a colonoscopy, which can find growths in the colon called polyps and remove them before they turn into cancer.

Why is cancer screening important?

Cancer screening saves lives and improves the quality of life for cancer survivors.

There have been many advances in cancer treatment over the past few years. Cancer no longer has to be a death sentence. Early treatment often results in a cure. Many people are now living well after a cancer diagnosis, often because their cancer was diagnosed and treated very early. For example, precancerous changes found with a Pap test can easily be treated and cured before cancer develops. A small breast cancer may be seen on a mammogram up to 2 years before it can be felt with a breast exam. The cancer can then be treated early, greatly increasing the chances for survival.

What are the recommended tests?

Screening tests that have been shown to have benefit are:

• breast mammograms to check for breast cancer in women
• Pap tests for precancer or cancer of the cervix (the opening of the uterus)
• fecal occult blood testing (FOBT) for cancerous or precancerous changes in the colon or rectum
• sigmoidoscopy or colonoscopy for prevention or early detection of colorectal cancer (cancer of the colon and rectum)
• digital rectal exams (DRE) and PSA for prostate cancer in men.

Mammograms

All women age 40 to 70 years old, who are in good health, should be screened for breast cancer with mammography every 1 to 2 years after counseling by their healthcare provider about the possible risks and benefits of the procedure. Comparing mammograms from year to year can help detect early cancer. If you are over 70, ask your healthcare provider how often you should have a mammogram. If you have a family history of early breast cancer (before age 40), you may need to start having mammograms earlier. Ask your provider.

If you have a risk for breast cancer that is higher than average, especially if you have a history of family members with breast cancers before the age of 50, ask your healthcare provider when you should start having mammograms and how often you should have them. If you have a very high risk, you may want to see a breast specialist.

Pap tests

Young women should have their first Pap test to screen for cervical cancer when they start having sexual intercourse or become 21. All women should have a Pap test once a year unless, after 3 Pap tests with normal results, their healthcare provider recommends having the test every 3 years.

Fecal occult blood testing (FOBT or FIT)

At age 50 men and women should start having fecal occult blood testing once a year to screen for colon and rectal cancer. Usually your provider will give you a kit to use at home for this test. You will put a tiny sample of bowel movement from 3 different days on the cards, pads, or wipes included in the kit. Usually you will then take or mail the samples to your provider or the lab.

The samples will be tested for blood. If there is blood in the samples, you will need more tests. A positive test for blood does not mean you have colon cancer. It means you need to have more tests to see whether you have colon cancer.

Sigmoidoscopy and colonoscopy

Sigmoidoscopy and colonoscopy are procedures that look for precancerous or cancerous changes in your colon and rectum. A slim, flexible, lighted tube is inserted into your rectum to view the inside of these organs. These tests are usually begun at age 50. Depending on your personal and family history, they may need to be repeated every 5 to 10 years. If you have a family history of colon cancer occurring before age 50 or a medical condition that increases your risk of colon cancer, you will need to start your screenings earlier. Discuss this with your healthcare provider.

Sometimes a test called a barium enema may be used instead of a sigmoidoscopy or colonoscopy to look for colon cancer.

Digital rectal exam

Healthcare providers usually offer a yearly PSA blood test and rectal exam to men age 50 or older. If you are at increased risk for prostate cancer (for example, if you are African American or have a family history of prostate cancer), your provider may recommend that you start screening earlier than age 50.

For the digital rectal exam, the healthcare provider puts a gloved finger in a man's rectum to feel the prostate gland. Prostate cancers feel very hard compared to normal prostate tissue. If something abnormal is felt, then you will have other tests to see if there is a tumor and whether it is a type of cancer that will spread.

The PSA (prostate specific antigen) level in the blood usually rises when a man has cancer of the prostate gland. However, it also rises if the prostate is infected or enlarged. (Enlarged prostates are common in middle age and later.) The test can give misleading results and cause undue anxiety, expense, and unnecessary medical procedures. For this reason, the PSA test is not recommended as a general screening test. However, because African American men have the highest rate of prostate cancer in the US, the PSA may be used to screen them. Also, men who have a history of prostate cancer in their families may be screened. Research is ongoing to see when and how PSA might be helpful as a screening test for prostate cancer.

There continues to be controversy about whether the PSA test should be used as a standard screening test. Some health care specialists point to the lives saved because of the test. Others point to the unnecessary biopsies and costs that have resulted from false positive tests. Whether you should have a PSA test is something you should discuss with your provider.

Are there other screening tests?

If breast cancer occurs often and at younger ages in your family, you may choose to have a BRCA gene test. This test can show if you have inherited a changed form of the gene that may greatly increase your risk of breast cancer. Most women who have this gene will have more frequent breast cancer screening. Some women who have BRCA1 or BRCA2 genes choose to have their breasts removed to keep from getting breast cancer.

How can I know when I should have screening tests?

Which tests you have and the timing of these tests depend on your personal and family history. For example, if someone in your family had colon cancer before age 50, you may need to start screening tests for this type of cancer at an earlier age. Be sure your healthcare provider knows your family history. Ask your provider which cancer screening tests you need and how often.