Checking for cancer (or for conditions that may become cancer) in people who have no symptoms is called screening. Cancer screening can help doctors find and treat several types of cancer early in its development.
Healthy lifestyle habits and regular screening exams can greatly reduce your risk for some types of cancer.
Risk Factors for Cancer
It is usually not possible to know exactly why one person develops cancer and another doesn’t. But research has shown that certain risk factors may increase a person’s chances of developing cancer. (There are also factors that are linked to a lower risk of cancer.)
You may be at a higher risk of developing cancer if you have a family history of cancer or of developing a second cancer if you’ve already had a cancer before. You should discuss with your physician what cancer screening tests are right for you and the recommended schedule if you are at a higher risk.
Early detection is important because when abnormal tissue or cancer is found early, it may be easier to treat. By the time symptoms appear, cancer may have begun to spread, making it harder to treat.
The use of screening tests to detect cancers early provides better opportunities for patients to obtain more effective treatment with fewer side effects. Patients whose cancers are found early and treated in a timely manner are more likely to survive these cancers than are those whose cancers are not found until symptoms appear.
Cancer Screening Tests
Several cancer screening tests have been shown to detect cancer early and to reduce the chance of dying from that cancer. Those tests include:
- Colonoscopy, sigmoidoscopy, and high-sensitivity fecal occult blood tests (FOBTs) - These tests have all been shown to reduce deaths from colorectal cancer. Colonoscopy and sigmoidoscopy also help prevent colorectal cancer because they can detect abnormal colon growths (polyps) that can be removed before they develop into cancer.
- Low-dose helical computed tomography - This test to screen for lung cancer has been shown to reduce lung cancer deaths among heavy smokers ages 55 to 74.
- Mammography - This method to screen for breast cancer has been shown to reduce mortality from the disease among women ages 40 to 74, especially those age 50 or older.
- Pap test and human papillomavirus (HPV) testing - These tests reduce the incidence of cervical cancer because they allow abnormal cells to be identified and treated before they become cancer. They also reduce deaths from cervical cancer. Testing is generally recommended to begin at age 21 and to end at age 65, as long as recent results have been normal.
Many of these test are covered 100% by most health insurance plans. Check with your insurance company to know which ones are covered with no out of pocket expense to you.
There are also additional tests that are used for cancer screening, but may require additional cancer screening tests. These screening methods include:
- Alpha-fetoprotein blood test - This test is sometimes used, along with ultrasound of the liver, to try to detect liver cancer early in people at high risk of the disease.
- Breast MRI - This imaging test is often used for women who carry a harmful mutation in the BRCA1 gene or the BRCA2 gene; such women have a high risk of breast cancer, as well as increased risk for other cancers.
- CA-125 test - This blood test, which is often done together with a transvaginal ultrasound, may be used to try to detect ovarian cancer early, especially in women with an increased risk of the disease. Although this test can help in diagnosing ovarian cancer in women who have symptoms and can be used to evaluate the recurrence of cancer in women previously diagnosed with the disease, it has not been shown to be an effective ovarian cancer screening test.
- Clinical breast exams and regular breast self-exams - Routine examination of the breasts by health care providers or by women themselves has not been shown to reduce deaths from breast cancer. However, if a woman or her healthcare provider notices a lump or other unusual change in the breast, it is important to get it checked out.
- PSA test - This blood test, which is often done along with a digital rectal exam, is able to detect prostate cancer at an early stage.
- Skin exams - Doctors often recommend that people who are at risk for skin cancer examine their skin regularly or have a health care provider do so.
- Transvaginal ultrasound - This is an imaging test which can create pictures of a woman’s ovaries and uterus, is sometimes used in women who are at increased risk of ovarian cancer (because they carry a harmful BRCA1 or BRCA2 mutation) or of endometrial cancer (because they have a condition called Lynch syndrome).
- Virtual colonoscopy - This test allows the colon and rectum to be examined from outside the body.
While there are clear benefits to cancer screening, screening tests can also carry risks. Not all screening tests are helpful and most have risks. It is important to know the risks associated with the test and whether it has been shown to improve one’s chances of surviving cancer.
Some of those risks include false-positive results, false-negative results, overdiagnosis, or complications from the test. It can be helpful for people to discuss the potential harms as well as benefits of different cancer screening tests with their doctors. The benefits often outweigh the risks, and it is important to check with your doctor for a complete list of expectations for each test.
Understanding Your Risks
Because cancer patients are at an increased risk of developing a second cancer; knowing when to screen, as well as the screening options available are very important for each patient to understand. Screening recommendations will vary for each patient, since each patient’s cancer is different. Several factors including your type of cancer, family history, age, and gender are considered in determining the screening that is right for you. It is important for you do discuss cancer screening with your oncologist.