New Study Offers Support for Prostate Testing  RONI CARYN RABIN SEPT. 4, 2017 https://www.nytimes.com/2017/09/04/well/live/new-study-offers-support-for-prostate-testing.html

Pros and Cons For men who are weighing the pros and cons of prostate cancer screening, a new study strengthens the evidence that testing can reduce deaths from this cancer, something two earlier large landmark clinical trials appeared to reach different conclusions about. The findings do not resolve many of the questions that remain about prostate cancer screening, since routine testing can lead to unneeded and potentially harmful treatments in men who do not need it. But it provides more information that experts can use to assess the benefits and risks of screening.

Two Trials One of the earlier trials, conducted in Europe, found that screening reduced deaths from prostate cancer by 21 percent, though it led many men down a bumpy road toward harmful or even unnecessary interventions. The other trial, based in the United States, found no difference in death rates between men who were randomly assigned to screening and those who were not. Both reports were published in 2009 in the New England Journal of Medicine.

Re-analysis For the new paper, published Monday in Annals of Internal Medicine, a broad consortium of scientists, including some of the investigators in the original studies, reanalyzed the data from the two trials using three different mathematical models. When they made a rigorous comparison between death rates among men who had actually undergone screening and men who had received no screening, the researchers concluded that screening tests reduced prostate cancer deaths by 25 to 32 percent. The reduction was primarily a result of the earlier detection of cancer, the researchers said.

PSA Test Prostate-specific antigen, or PSA, is a protein produced by cells of the prostate gland. The PSA test measures the level of PSA in a man’s blood. For this test, a blood sample is sent to a laboratory for analysis. The results are usually reported as nanograms of PSA per milliliter (ng/mL) of blood. The blood level of PSA is often elevated in men with prostate cancer, and the PSA test was originally approved by the FDA in 1986 to monitor the progression of prostate cancer in men who had already been diagnosed with the disease. In 1994, the FDA approved the use of the PSA test in conjunction with a digital rectal exam (DRE) to test asymptomatic men for prostate cancer. Men who report prostate symptoms often undergo PSA testing (along with a DRE) to help doctors determine the nature of the problem. From National Cancer Institute https://www.cancer.gov/types/prostate/psa-fact-sheet

Sensitivity / Specificity 4 >4 Originally, the “cut point” was a score of 4 or greater. There was worry about “missing” some cancer, so many doctors used a cut point of 3. If you do that what happens? You find more cancer AND you get more false positives. We’ll talk a lot about this later in the term.