So what is the balance of benefit and harms? Should we make that judgment on what we know, or on what we believe?
Science trumps common sense. For every 1000 men screened, at most, one will avoid a prostate cancer death at 10 years. But 30 to 40 will have erectile dysfunction, urinary incontinence, or both due to treatment, 2 men will experience a serious cardiovascular event, one will have a venous thromboembolic event, and one in 3000 screened will die from complications of surgical treatment.6
The USPSTF concluded that the benefits of PSA screening do not outweigh the harms, but acknowledged that shared decision making is still appropriate when a physician feels obliged to offer the test or a patient requests it.
What does shared decision making look like? Just offering screening and answering any questions is not good enough. We do an enormous disservice to our patients if we pretend that this is just a blood test and that we can decide later what to do with the information. Men will get biopsies and there will be complications. Cancer will be detected, and men will be treated, many unnecessarily.
We need to tell our patients that the likelihood of avoiding a prostate cancer death over 10 years as a result of regular PSA screening is at most very small, and that many more men will suffer the harms of unnecessary treatment than will benefit. A few will die prematurely as a result of the complications of treating a screen-detected cancer.
If, with this knowledge, a patient places a higher value on the possibility of avoiding a prostate cancer death than he does on the known harms of diagnosis and treatment, he can still decide to be screened. He has made an informed decision. However, routine screening for prostate cancer in the absence of a truly informed decision is unacceptable.