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SubUrban Icon CANCER SCREENING

Cancer screening implies checking for cancer in asymptomatic people. Screening can help find several types of cancers early, before they manifest clinically. Early detection is important because it allows early treatment and offers greater chances of recovery and even cure. By the time symptoms appear, the cancer may have begun to metastasize and be harder to treat.”

But it is important to keep in mind that, as with any test, screening tests have both pros and cons:

  1. Overdiagnosis: The screening test correctly shows that a person has cancer, but it might not clearly indicate that the cancer is slow-growing and would not have harmed that person in his or her lifetime, leading to unnecessary treatment.
  2. False-positives: The test indicates that cancer may be present even though it is not. False-positive test results can cause anxiety and are usually followed by additional tests and procedures that also have potential side-effects.”
  3.  False-negatives: The test fails to detect the presence of cancer. False-negative test results may lead to a false sense of security, leading to delays in diagnosis and possibly causing an individual to put off seeking medical care even if symptoms develop.”

TYPES OF CANCER SCREENING TESTS:

Not all cancers currently have screening tests, but those that do have specific tests.

Breast cancer:

  1. Mammography
  2. Clinical breast examination
  3. Breast self-examination

WHO recommendations

The U.S. Preventive Services Task Force (USPSTF) recommends that women ages 50 to 74 have mammography every 2 years. They recommend that mammography be considered in women ages 40 to 49 after evaluating the risks and benefits of this test with a doctor.(4)

Cervical cancer:

  1. Pap smear examination – Conventional or the recommended Liquid Based Cytology (LBC) testing
  2. Human papillomavirus (HPV) testing

Visual inspection with acetic acid (VIA) is a screening test that can be done with few tools and the naked eye. This screening test is very useful in places where access to medical care is limited.”

The ACS/ASCCP Cervical Cancer Screening Recommendations 2020

*Adequate negative prior screening (condition for cessation) is currently defined as 2 consecutive, negative primary HPV tests, or 2 negative co-tests, or 3 negative cytology tests within the past 10 years, with the most recent test occurring within the past 3 – 5 years.

Colorectal cancer:

Five types of tests are used to screen for colorectal cancer (CRC);

  1. Faecal occult blood test (guaiac faecal occult blood / faecal immunochemical test)
  2. Sigmoidoscopy
  3. Colonoscopy
  4. Virtual colonoscopy  ( CT colonography )
  5. Stool DNA test

Studies have shown that screening for colorectal cancer using digital rectal exam does not decrease the number of deaths from the disease.”

American Cancer Society recommendations for Colorectal Cancer Screening

The American Cancer society does not provide recommendations for high-risk individuals. But the same have been offered by the US Multi Society Task-Force for Colorectal Cancer(9

Prostate Cancer :

  1. Digital rectal examination (DRE) 
  2. Prostate-specific antigen (PSA) test. 

A prostate cancer gene 3 (PCA3) RNA test may be used for certain patients. The PCA3 gene assay was approved by the U.S. Food and Drug  Administration in early 2012, with the intended use to aid in the decision for repeat biopsy in men with a previously negative biopsy for an elevated PSA and for whom a repeat biopsy is being considered for a persistently elevated PSA. This test is performed on a urine sample collected after an attentive digital rectal examination (DRE) – several strokes applied firmly to the prostate to the right and left prostatic lobes). Using a threshold value of 60, this test enhances the detection of prostate cancer while reducing the number of biopsies in men who are expected to ultimately have a negative biopsy.

According to the USPSTF, for men aged 55 to 69 years, the decision to undergo periodic prostate-specific antigen (PSA)-based screening for prostate cancer should be an individual one. It also recommends against PSA-based screening for prostate cancer in men 70 years and older.”

The Memorial Sloan Kettering prostate cancer screening guidelines state that men aged 45-70 should have their PSA levels checked. Testing for men between 7175 years of age should be based on past PSA levels and the health of the man. These guidelines do not recommend testing for men ages 76 or older. 12)

Lung cancer:

  1. Low-dose computed tomography (LDCT)

The USPSTF recommends annual screening for lung cancer with low-dose computed tomography (LDCT) in adults aged 55 to 80 years who have a 30 pack-year smoking history and currently smoke or have quit within the past 15 years. Screening should be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery.(13)

In 2012, the American College of Chest Physicians, the American Society of Clinical Oncology, and the American Thoracic Society recommended screening for lung cancer with LDCT, for persons aged 55 to 74 years who have a 230 pack-year smoking history and currently smoke or have quit in the past 15 years.(14)

The American Association for Thoracic Surgery recommends annual screening with LDCT in current and former smokers aged 55 to 79 years who have a 30 pack-year smoking history. It also recommends annual screening starting at age 50 to 79 years in patients who have a 20 pack-year smoking history and additional comorbid conditions that produce a cumulative risk for cancer of at least 5% over the next 5 years. Furthermore, it recommends annual screening in long-term cancer survivors aged 55 to 79 years.(15)

In 2013, the American Cancer Society also began recommending screening for lung cancer with LDCT in high-risk patients who are in relatively good health and meet the following criteria – persons aged 55 to 74 years who have a 230 pack-year smoking history and currently smoke or have quit in the past 15 years.(16)

References:

  1. Cancer Screening [Internet]. Cancer.Net. 2012 [cited 2020 Feb 2]. Available from: https://www.cancer.net/navigating-cancer-care/prevention-and-healthy-living/cancer-screening
  2. Screening for Cancer [Internet). National Cancer Institute. 2015 [cited 2020 Feb 2]. Available from: https://www.cancer.gov/about-cancer/screening
  3. World Health Organization (WHO). WHO position paper on Mammography Screening [Internet]. 2014 [cited 2021 Feb 2).

Available from: https://www.who.int/cancer/publications/mammography_screening/en/

References:

4. Final Recommendation Statement: Breast Cancer: Screening – US Preventive Services Task Force [Internet]. [cited 2020 Feb 2]. Available from: https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/breast-cancer-screening 1

5. Cervical Cancer – Screening and Prevention (Internet]. Cancer.Net. 2012 [cited 2020 Feb 2]. Available from: https://www.cancer.net/cancer-types/cervical-cancer/screening-and-prevention

6. Fontham ETH, Wolf AMD, Church TR, Etzioni R, Flowers CR, Herzig A, et al. Cervical cancer screening for individuals at average risk: 2020 guideline update from the American Cancer Society. CA Cancer J Clin. 2020 Sep;70(5):321-46.

7. Colorectal Cancer Screening (PDQ®)-Patient Version [Internet). National Cancer Institute. 2019 [cited 2020 Feb 2]. Available from: https://www.cancer.gov/types/colorectal/patient/colorectal-screening-pdq

8. Wolf AMD, Fontham ETH, Church TR, Flowers CR, Guerra CE, LaMonte SJ, et al. Colorectal cancer screening for average-risk adults: 2018 guideline update from the American Cancer Society: ACS Colorectal Cancer Screening Guideline. CA Cancer J Clin. 2018 Jul;68(4):250–81.

9. Rex DK, Boland CR, Dominitz JA, Giardiello FM, Johnson DA, Kaltenbach T, et al. Colorectal cancer screening: Recommendations  for physicians and patients from the U.S. Multi-Society Task Force on Colorectal Cancer. Gastrointest Endosc. 2017 Jul;86(1):18–33.

10. Prostate Cancer Screening (PDQ®)-Health Professional Version [Internet). National Cancer Institute. 2019 [cited 2020 Feb 2]. Available from: https://www.cancer.gov/types/prostate/hp/prostate-screening-pdq

11. Final Update Summary: Prostate Cancer: Screening – US Preventive Services Task Force (Internet]. [cited 2020 Feb 2]. Available from: https://www.uspreventiveservicestaskforce.org/Page/Document/UpdateSummaryFinal/prostate-cancer-screening 1

12. Prostate Cancer Screening Guidelines | Memorial Sloan Kettering Cancer Center [Internet]. [cited 2020 Feb 2]. Available from: https://www.mskcc.org/cancer-care/types/prostate/screening/screening-guidelines-prostate

13. Final Recommendation Statement: Lung Cancer: Screening – US Preventive Services Task Force [Internet]. [cited 2020 Feb 2]. Available from: https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/lung-cancer-screening

14. Bach PB, Mirkin JN, Oliver TK, Azzoli CG, Berry DA, Brawley OW, et al. Benefits and Harms of CT Screening for Lung Cancer: A Systematic Review. JAMA. 2012 Jun 13;307(22):2418.

15. Jaklitsch MT, Jacobson FL, Austin JHM, Field JK, Jett JR, Keshavjee S, et al. The American Association for Thoracic Surgery guidelines for lung cancer screening using low-dose computed tomography scans for lung cancer survivors and other high-risk groups. J Thorac Cardiovasc Surg. 2012 Jul;144(1):33–8.

16. Wender R, Fontham ETH, Barrera E, Colditz GA, Church TR, Ettinger DS, et al. American Cancer Society lung cancer screening guidelines: American Cancer Society Lung Cancer Screening Guidelines. CA Cancer J Clin. 2013 Mar;63(2):106–17.