PSA is resuscitated briefly

A study in today’s NEJM shows that early cancer may benefit from surgery. However, PSA makes an unwelcome addition to the study. Somehow, the fact that the study participants had to be “diagnosed” through PSA screening may be interpreted as evidence that this study supports PSA screening.

After reading this and the preceding paper, I am still unclear where is PSA screening coming into the picture. The participants were required to be previously diagnosed with prostate cancer by any means. I could not find anywhere a sign that they were required to be asymptomatic before their PSA was first measured. But after this diagnostic was made and after they agreed to participate in the study, their PSA was measured again, quite opposite to the order of action in real-life screening, where PSA measurement come first, diagnosis – later. Because the study does not start at PSA screening time, the number of unnecessary biopsies to get to this sample size is not available. Unsurprisingly, in the study population, the PSA had a (pardon the pun) healthy increase to a median of 7, whereas in-real life screening, difficult questions are asked at 4.

If the hypothesis was, as the title says, surgery helps well-diagnosed patients, then yes, the authors have provided evidence, although I am not sure whether this is novel. The novelty, PSA screening helps, is not supported. Eighteen years in the making, PIVOT remains an informative trial, but does not answer today’s questions.

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