Update on Prostate Cancer Screening

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www.mthawthornmedical.com.au

Health Editor’s Note: There is new evidence to add to the controversy over whether having the Prostate Specific Antigen (PSA) blood test will improve your chances of survival when diagnosed with prostate cancer. The issue of false positives from the PSA test, that often lead to unnecessary biopsy or even surgery not to mention the stress of being told you have cancer, are troublesome.

The recent medical view, that PSA screening does not reduce prostate cancer deaths, has been rethought with new studies that show that the PSA screening will reduce prostate cancer deaths by 25% to 31% and 27% to 32% in two trials. If there is a test for cancer that just requires giving a few CCs of blood, why not go ahead and have it done and then carefully go over the results with your doctor.

You and your doctor and perhaps a second opinion can determine whether your test result actually reflects that you do indeed have prostate cancer. Prostate cancer is not a fast growing cancer and depending on your age your doctor may not order any treatment. As always, be informed and be able to make your own decisions about how you want to go forward if, you are diagnosed with prostate cancer… Carol ]

Study Finds Overall Prostate Cancer Mortality Decreases with PSA Screening. But questions remain about how best to screen so the benefits outweigh the harms.

By Joan Zolot, AJN The American Journal of Nursing: December 2017 – Volume 117 – Issue 12 – p 16

A new study challenges the prevailing view of recent years that screening for prostate cancer does not reduce prostate cancer mortality.

The researchers found significant benefit from screening versus no screening after reanalyzing data from two large studies that formed the basis of a 2012 recommendation by the U.S. Preventive Services Task Force (USPSTF) against routine screening using the prostate-specific antigen (PSA) blood test.

The USPSTF’s recommendation, which was based on the two studies even though they had conflicting results, has led to a decreased use of the PSA test.

The Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO), conducted in the United States, found no difference in prostate cancer mortality between 38,340 men who received PSA screening and 38,343 men in a control group.

The European Randomized Study of Screening for Prostate Cancer (ERSPC), however, found a 21% reduction in prostate cancer deaths among 72,473 screened men, compared with the control group of 88,921.

The new study reanalyzed the PLCO and ERSPC data and found that in both trials, PSA screening was associated with reduced prostate cancer deaths but only after accounting for a significant problem within the PLCO study.

The researchers found that 50% of the men assigned to the PLCO control group actually received at least one PSA screening during the study—in fact, many had more than one—through their routine medical care. This “contamination” minimized differences in prostate cancer mortality during follow-up between the screened and the control groups.

To correct for this flaw in the PLCO trial, the new study estimated the intensity of screening in each group relative to no screening and concluded that PSA screening reduced prostate cancer mortality by 25% to 31% in the ERSPC trial and by 27% to 32% in the PLCO trial.

A known drawback of PSA testing is the risk of false positives potentially leading to unnecessary diagnostic procedures and treatment. Some prostate cancers are “indolent,” meaning they are slow growing and unlikely to lead to death or even to cause symptoms. How to use the PSA test to save lives while minimizing unnecessary treatment remains the challenge. The USPSTF is in the process of updating its recommendations on prostate cancer screening.

REFERENCE
Tsodikov A, et al Ann Intern Med 2017;167(7):449-55; Vickers AJ Ann Intern Med 2017 167 7 509–10

 

6 COMMENTS

    • Neil,
      I did some checking on this and I found this out: A new urine test for prostate cancer that measures minute fragments of RNA is now commercially available to men nationwide through the University of Michigan MLabs. The new test—Mi-Prostate Score (MiPS)—improves the utility of the PSA blood test, increases physicians’ ability to pick out high-risk prostate tumors from low-risk tumors in patients, and may help tens of thousands of men avoid unnecessary biopsies.

      The MiPS test incorporates blood PSA levels and two molecular RNA markers specific for prostate cancer in one final score that provides men and their doctors with a personalized prostate-cancer risk assessment. https://www.pcf.org/news/new-urine-test-for-prostate-cancer-available-unlike-psa-test-is-ultra-specific-for-prostate-cancer/

      But please note that the urine test is done in conjunction with the blood PSA. All that is being developed is to prevent deaths from prostate cancer. Carol

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