Cancer Screening

Cancer Screening Tests

Cancer is more common than many people realize. According to the National Cancer Institute, approximately 38.5 percent of Americans will be diagnosed with cancer in their lifetimes. An estimated 1,688,780 Americans will be diagnosed with cancer in 2017, and there will be 600,920 cancer deaths. These numbers serve as a stark reminder of the importance of cancer screening as a part of a solid preventive healthcare plan. Cancer screening tests look for cancer before any symptoms are present. The goal of screening tests is to detect cancers in their earliest stages, which often increases odds of successful treatment.

When should I start getting screened for cancer?

The answer to that question depends largely on your personal circumstances. For instance, if you have personal risk factors for cancer, such as a family history of certain cancers, genetic disorders that increase your risk or lifestyle factors that make cancer more likely, you will need cancer screening more often than a person with average risk levels. The American Cancer Society offers general guidelines on cancer screening in adults beginning at age 21. Their recommendations for people with average levels of cancer risk are as follows:

• Colon cancer – Both men and women should start getting screened for colon cancer at age 50.
• Prostate cancer – Risk for prostate cancer begins to rise around age 50, so this is prime time to begin regular screenings for this cancer type.
• Cervical cancer – All women aged 21 and over should be screened for cervical cancer regularly. Screening recommendations are a pap test every three years, or a pap test and HPV test every 5 years.
• Breast cancer – Women should be screened for breast cancer once yearly, beginning at age 40 to 45.
• Lung cancer – Men and women with a history of smoking should be screened for lung cancer once a year after age 55.

People who are at increased risk for cancer due to a family history of cancer, certain genetic disorders and health conditions, or other serious risk factors typically need earlier and/or more frequent screening than the average person, and may require a screening for more cancer types. For that reason, it is important to look to your personal healthcare provider for help in deciding which cancer screening tests you should be having regularly and when you should begin those screenings.

How do you screen for cancer?

Since there are many different types of cancer types, screening for cancer takes many forms. These include:

• Physical exams – This is an examination of the body to look at general health factors and check for signs of cancer.
• Examination of personal and family health histories – This checks into family health history, past health problems, lifestyle factors and habits that may help evaluate a person's individual cancer risk.
• Medical imaging procedures – These are procedures that allow healthcare professionals to look inside the body to aid in finding early signs of cancer.
• Genetic tests – These tests look for specific genes and/or mutations linked to cancers.
• Laboratory tests – These tests use samples of tissue, blood, urine or other bodily substances to look for indications of cancer.

What is a cancer screening test?

A cancer screening test is a medical procedure that finds cancer or detects indications that cancer may be developing in the body. Many of the most common cancer screening testing tools are blood tests that look for tumor markers or measure levels of substances in the blood that can indicate certain types of cancer development. Examples of cancer screening blood tests include:

• PSA test – This test measures levels of prostate-specific antigen (PSA) in the blood. Higher than normal levels of PSA can be an indication of prostate cancer and other prostate problems.
• CA-125 test – CA 125 is a protein produced by the fallopian tubes. Higher than normal levels of this protein in the blood can be an indication of cancer, especially ovarian cancer.
• Cancer Antigen (CA) 27.29 – This test measures the level of CA 27.29 antigen, which is found in the blood of individuals who have developed breast cancer.
• Alpha-fetoprotein (AFP) – This test detects and measures levels of AFP in the blood. Abnormal levels of this protein can be an indication of cancer of the liver, testicles, ovaries, stomach, pancreas, or brain, and can also be associated with renal cell cancer, Hodgkin's disease or lymphoma.
• Carcinoembryonic Antigen (CEA) – This test measures levels of CEA in the blood, which is a tumor marker associated with colon and rectal cancer, as well as cancers of the pancreas, lung, ovary and breast.
• Carbohydrate Antigen (CA) 19-9 – This test detects and measures proteins produced by pancreatic or gastrointestinal cancer cells, providing a powerful tool to aid in diagnosing these cancers.
• Complete blood count (CBC) – This test measures the amount of various types of blood cells in the blood, as well as indications of the health and function of those cells. Abnormal results can aid in detecting blood cancers.

What are some diagnostic techniques used to detect cancer?

Often, cancer screening lab tests are the first approach for detecting cancer, but results that may indicate cancers are typically followed up with other diagnostic tools. These include medical imaging tests, such as colonoscopy or sigmoidoscopy exams to look for colon cancer, MRI and or CT scans to look for signs of lung, breast, liver or prostate cancer, or dermoscopy to detect skin cancers, among others. The particular diagnostic tools used in each case will vary according to the specific type of cancer suspected, as well the preferences of healthcare providers and patients.

Guide: What You Need To Know About Cancer and Cancer Testing