Public Health Topics
Cancer Screenings

Cancer screening is looking for cancer before symptoms appear. When cancer is found early, it may be easier to treat or cure. When symptoms appear, the cancer may have grown and spread, making it harder to treat or cure. Several cancer screening tests have been shown to find cancer early and reduce the chance of dying from that cancer.

In addition to these benefits, cancer screening tests can have potential harms:

  • Some may cause bleeding or other health problems.
  • They can have false-positive results—the test indicates that cancer may be present even though it is not. This can cause anxiety and are usually followed by additional tests and procedures that also have potential harms.
  • They can have false-negative results—the test indicates that cancer is not present even though it is. This may provide false reassurance, leading to delays in diagnosis and possibly causing an individual to put off seeking medical care even if symptoms develop.
  • It can lead to overdiagnosis—the screening test correctly shows that a person has cancer, but the cancer is slow growing and would not have harmed that person in their lifetime. Treatment of such cancers is called overtreatment.

Cancer Screening Resources:

 It’s important to talk with your doctor about when and how often you should be screened. Depending on your personal health history, family health history or screening results, your doctor may recommend a different screening schedule.

For more information on preventive care during COVID-19, visit  

Cancer Screening Tests
Breast Cancer
  • Summary of screening test: Mammograms are the best way to find breast cancer early, when it is easier to treat. A mammogram is an x-ray that allows for examination of the breast tissue for any suspicious areas. The breast is exposed to a small dose of ionizing radiation that produces an image of the breast tissue.
  • Who should get screened: The U.S. Preventive Services Task Force recommends women get a mammogram every two years if you are 50-74 years old and are at average risk for breast cancer. If you are 40-49 years old, talk with your doctor about when and how often you should get a mammogram.
  • Benefits of screening: Breast cancer death rates declined 40% from 1989 to 2016 among women. The progress is attributed to improvements in early detection (Source: American Cancer Society).
  • Risk factors: There are risk factors that one cannot change such as getting older, mutations in the BRCA1 or BRCA2 genes and family history of breast cancer, to name a few. The risk factors that one can change are not being physically active, being overweight or obese after menopause and drinking alcohol. Lower the risk for breast cancer by exercising regularly, limiting your alcohol consumption, if you are taking hormone replacement therapy or birth control pills, ask your doctor about the risks, and breastfeed your children, if possible.
  • Resources:
Cervical Cancer
  • Summary of screening test: The Pap test or Pap smear can find abnormal cells in the cervix which may turn into cancer. The HPV test looks for the virus (human papillomavirus) that can cause these cell changes. Pap tests also can find cervical cancer early, when the chance of being cured is very high.
  • Who should get screened: The U.S. Preventive Services Task Force recommends screening for cervical cancer every 3 years with the Pap test alone in women 21-29 years old. For women 30-65 years old, the recommended screening is every 3 years with Pap test alone, every 5 years with HPV testing alone, or every 5 years with HPV testing in combination with Pap test. Talk with your doctor about which testing option is right for you and how often you should get tested.
  • Benefits of screening: Regular screening tests starting at age 21 is the most important thing you can do to help prevent cervical cancer.
  • Risk factors: Almost all cervical cancers are caused by HPV. Other risk factors include having HIV (the virus that causes AIDS), smoking, using birth control pulls for five or more years, having given birth to three or more children and having several sexual partners. Lower the risk for cervical cancer by getting the HPV vaccine, avoiding smoking, using condoms during sex and limiting the number of sexual partners.  
  • Resources:
Colorectal (Colon) Cancer
  • Summary of screening test: Colorectal cancer almost always develops from precancerous polyps (abnormal growths) in the colon or rectum. Screening tests can find precancerous polyps, so they can be removed before they turn into cancer. Screening tests also can find colorectal cancer early, when treatment works best. Screening tests include colonoscopy, sigmoidoscopy, and stool tests (high-sensitivity fecal occult blood tests and stool DNA tests).
  • Who should get screened: The U.S. Preventive Services Task Force recommends that adults 50-75 years old be screened for colorectal cancer. Adults 76-85 years old should ask their doctor if they should be screened. 
  • Benefits of screening: The most effective way to reduce the risk of colorectal cancer is to get screened for colorectal cancer routinely, beginning at age 50.
  • Risk factors: Risk for getting colorectal cancer increases with age; about 90% of cases occur in people who are 50 years old or older. Other risk factors include having inflammatory bowel disease, family history of colorectal cancer and other lifestyle factors. Lower the risk by regularly exercising, eating a diet high in fruits, vegetables and fiber, and limiting alcohol and tobacco use.
  • Resources:
Lung Cancer
  • Summary of screening test: The only recommended screening test for lung cancer is low-dose computed tomography (also called a low-dose CT scan, or LDCT). During an LDCT scan, you lie on a table and an x-ray machine uses a low dose of radiation to make detailed images of your lungs. 
  • Who should get screened: The U.S. Preventive Services Task Force recommends yearly lung cancer screening for people who have a history of heavy smoking, and smoke now or have quit within the past 15 years and are between 55-80 years old. Heavy smoking means a smoking history of 30 pack years or more. A pack year is smoking an average of one pack of cigarettes per day for one year.
  • Risk factors: Cigarette smoking is the number one risk factor for lung cancer. In the United States, cigarette smoking is linked to about 80-90% of lung cancer deaths. For more information on tobacco use and control policies in the Beach Cities, click here. Other risk factors include secondhand smoke, exposure to radon and family history of lung cancer. Lower the risk by not smoking, avoiding secondhand smoke and getting your home tested for radon.
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Skin Cancer
  • The U.S. Preventive Services Task Force has concluded that there is not enough evidence to recommend for or against routine screening (total body examination by a doctor) to find skin cancers early. This recommendation is for people who do not have a history of skin cancer and who do not have any suspicious moles or other spots. Report any unusual moles or changes in your skin to your doctor. Also talk to your doctor if you are at increased risk of skin cancer.
  • Risk factors: People with certain characteristics are at greater risk – lighter skin color, skin that burns or freckles easily, blue or green eyes, blond or red hair, certain types and large number of moles, family history of skin cancer, and older age.
  • Reducing exposure to UV rays can help keep skin healthy and lower risk of skin cancer. Protect skin by staying in the shade especially during midday hours, wear sunglasses, hats and clothing that covers your arms and legs, use sunscreen with an SPF of 15 or higher with UVA and UVB protection, and avoid indoor tanning.
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Prostate Cancer
  • Summary of screening test: There is no standard test to screen for prostate cancer. The two most common tests are described below.
    • Prostate Specific Antigen (PSA) Test: This test measures the level of PSA in the blood. PSA is a substance made by the prostate. As a rule, the higher the PSA level in the blood, the more likely a prostate problem is present. But many factors, such as age and race, can affect PSA levels. Some prostate glands make more PSA than others. If the PSA test is abnormal, your doctor may recommend a biopsy to find out if you have prostate cancer.
    • Digital Rectal Examination (DRE): A health care provider inserts a gloved, lubricated finger into a man’s rectum to feel the prostate for anything abnormal, such as cancer. In 2018, the U.S. Preventive Services Task Force stated that it does not recommend DRE as a screening test because of lack evidence on the benefits.
  • Who should get screened: The U.S. Preventive Services Task Force recommends men who are 55-69 years old talk to their doctor and make individual decisions about being screened for prostate cancer with a PSA test. Men who are 70 years old and older should not be screened for prostate cancer routinely.
  • Risk factors: All men are at risk for prostate cancer. Men who are older, African American or have a family history of prostate cancer are at increased risk.
  • Resources: