What's Up Doc? So many medical screening tests! Are they all really necessary?

Dr. Jeff Hersh
·4 min read
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Q:  Are all the cancer screening tests my doctor recommended really needed?

A:  Cancer staging is the way the characteristics of cancer, including:

  • Details of its size.

  • Whether or not and where it may have spread to (for example not spread/only in the original location, spread to local structures and/or lymph nodes, or spread distantly to other body organs/locations).

  • The aggressiveness of the subtype of the cancer.

  • Other other factors (cancer markers, other characteristics), are specified.

Together, all this information informs the recommended treatment(s) and the prognosis for the individual patient.

In general, earlier stage cancers (whether smaller in size, not yet spread, less aggressive, other lower risk factors) have a better prognosis and/or require less aggressive treatment (for example some may be treated with surgery and not require adjuvant chemotherapy or other treatments) than later stage cancers. The problem is that earlier stage cancers often do not cause any symptoms. Cancer screening is when a patient is evaluated for possibly having cancer before they develop any symptoms. That is why certain cancer screenings are recommended and can be very beneficial to the patient.

Dr. Jeff Hersh
Dr. Jeff Hersh

For cancer screening to be overall beneficial, the improvement in prognosis/treatment/etc. must outweigh any potential risks from the screening process, including possible issues arising from false positive screening results, complications of the screening itself (for example a bowel perforation from a colonoscopy, which although very uncommon can occur), etc. Therefore, screening is only recommended when the benefit of an earlier diagnosis from the screening (specifically evaluated in the setting of the patient’s risk factors/likelihood of having the cancer being screened for including consideration of their age, prior medical history, family history, and other risk factors like a history of smoking, etc.) far outweigh any potential risks/complications of the screening.

Many authoritative organizations do the above evaluation(s) to determine what cancer screening is recommended and for whom. This includes the American Cancer Society (ACS), societies specific for certain types of cancers, and the United States Preventative Task Force (the USPTF is “an independent, volunteer panel of national experts in disease prevention and evidence-based medicine. The Task Force works to improve the health of people nationwide by making evidence-based recommendations about clinical preventive services”).

In addition to regular checkups with your primary care clinician, here is a very high-level overview of the cancer screenings recommended by the USPTF and the ACS:

Breast cancer

  • Genetic counseling/testing for women with a concerning family/personal history of breast or ovarian cancer at a young age.

  • USPTF recommends biennial mammography for women aged 50-74 years, the ACS recommends annual screening starting age 45 (and even considering starting at age 40) and then biennial age 55 and older.

Colorectal cancer

  • Screening for all patients aged 45-75, with multiple ways to do this screening and variable frequencies of the screenings depending on the patient’s individual risk factors and the type of screening selected.

Cervical cancer

  • USPTF and ACS recommend PAP smears every three years for women aged 21-65 years and adding an hrHPV (a DNA HPV test) every five years for women aged 30-65.

Lung cancer

  • Low-dose helical CT scan screening for people aged 50-80 with a 20+-pack year history who are still smoking or have quit in the last 15 years.

Prostate cancer

  • Men should have a discussion with their primary care clinician to decide what may be best for them.

There are many other screenings recommended by the USPTF including:

  • For cardiovascular disease: examples include blood pressure check, diabetes check, screening for abdominal aortic aneurysms, others.

  • During pregnancy: for example, screening for several infectious diseases, gestational diabetes, others.

  • In sexually active patients: for example, screening for certain sexually transmitted diseases.

  • For other conditions that may be common in selected patient groups: examples include depression, obesity, hepatitis B and C, osteoporosis, others.

There is also a lot of work being done to develop other possible cancer screening approaches. For example, some specialized blood tests are being developed to look for certain proteins/cell breakdown products that might indicate cancer in a patent, DNA tests to identify risk factors for certain cancers (an example is the BRCA gene as a risk factor for breast/ovarian cancer), and others.

The bottom line is that an ounce of prevention is worth many pounds of (attempt to) cure for many cancers, so you should discuss with your primary care clinician what screenings may be right for you, and then comply with their recommendations.

Jeff Hersh, Ph.D., M.D., can be reached at DrHersh@juno.com.

This article originally appeared on MetroWest Daily News: Some cancer screening tests can catch disease before symptoms arise