To PSA or not PSA? You choose – we don’t know.
The draft guidelines for prostate cancer screening in Australia are currently out for comment.
These are interesting guidelines as they seem to pursue a different strategy to the breast, cervical and colorectal cancer screening programs. Although, obviously, nobody is coerced to participate in these programs, the underlying principle is population screening. The prostate guidelines consciously shift the focus to one of autonomy or more specifically informed choice guided by decision support processes or the use of decision aids.
The main evidence used to justify PSA screening is a trial that demonstrates an an absolute reduction of 0.1 deaths per 1000 person years. This translates into inviting to screening 1055 men, detecting 37 cancers and preventing 1 death due to prostate cancer. This may be associated with both unnecessary biopsies due to false positive PSA and also potentially unnecessary and expensive treatments. Many men won’t die of their prostate cancer but will still undergo treatments that may results in urinary and sexual dysfunction.
So PSA screening is controversial – the solution is to let the consumer decide. This all depends on successful implementation of evidence that support the use of decision support aids with men contemplating prostate cancer screening. Whilst I agree implementation of such decision support is important the arch cynic in me is doubtful about this approach unless it is adequately supported – something that might change the whole cost-effectiveness of the approach. The guideline itself points out the barriers to use of decision aids such as poor uptake to date, the time required and the training needed. It also doesn’t mention what would be considered the consensus messages…..are we talking absolute or relative risks here?
Within a week of the guidelines being published the Federal Government announced a revision of its’ copayment program. If implemented general practice will need to work out how to incorporate decision support in a cost-effective manner. If you were really doing it properly you might actually need two sessions with the GP – a short and a long appointment. Will this really be an incentive for GPs or will they just sign the pathology request? At least they will get CME points for having attended a training session.
There are other issues not being addressed by this disease specific guideline. The PSA screening moment is a moment to address other primary preventative issues like smoking, alcohol and other drug use, cardiovascular risk, bowel cancer screening, etc, etc. The prostate screening decision could be bundled with other health interventions for complete care.
The cost of care after the diagnosis of prostate cancer is also not addressed. Currently it is fashionable to offer robotic prostate cancer surgery, largely in private facilities. The price of these procedures can be very expensive with relatively marginal improvements compared to open procedures – mostly in relation to length of stay and acute complications rather than differences in late complications and cancer outcomes. Price variation and outcomes of practitioners should be published in order to get the best value from the guidelines and subsequent decisions about treatment.
I support informed decision making and patient autonomy but when we inform the patients we better add the disclaimer up-front that we can’t actually decide ourselves (based on the current evidence) what is the right thing to do.