Estimating the benefits and harms of PSA testing in the Australian context

Results from international randomised controlled trials have been inconsistent as to whether prostate specific antigen (PSA) testing is associated with a mortality benefit. However, the PSA test is commonly used to test asymptomatic men for prostate cancer in Australia. The harms, including additional diagnostic evaluation and exposure to treatment regimens and their side-effects, may be substantial. It is possible that less frequent testing, a clearly identified target population and careful consideration of thresholds and triage protocols for men with elevated PSA could be used to achieve a more advantageous balance between the benefits and harms of testing. It is not practical to assess a wide range of potential testing strategies via clinical trials, since any testing-associated benefits for prostate cancer-specific mortality would take years to accrue and would also be logistically challenging. Furthermore, the benefits, harms and cost-effectiveness of testing in Australia depend on several factors specific to the local context, including testing uptake and the risk profile of the population. Mathematical modelling will therefore play an important role in synthesising the data from international trials with known local testing, disease and treatment variables. Here, we review the international literature on models of PSA testing and conclude that investment in a carefully calibrated and validated population model of prostate cancer in Australia will provide an important platform for estimating the impact of future candidate strategies for testing for prostate cancer.