Trends in Prostate Specific Antigen (PSA) testing and prostate cancer incidence and mortality in Australia: A critical analysis.

ABSTRACT

BACKGROUND: Population trends in PSA testing and prostate cancer incidence do not perfectly correspond. We aimed to better understand relationships between trends in PSA testing, prostate cancer incidence and mortality in Australia and factors that influence them. METHODS: We calculated and described standardised time trends in PSA tests, prostate biopsies, treatment of benign prostatic hypertrophy (BPH) and prostate cancer incidence and mortality in Australia in men aged 45-74, 75-84, and 85 + years. RESULTS: PSA testing increased from its introduction in 1989 to a peak in 2008 before declining in men aged 45-84 years. Prostate biopsies and cancer incidence fell from 1995 to 2000 in parallel with decrease in trans-urethral resections of the prostate (TURP) and, latterly, changes in pharmaceutical management of BPH. After 2000, changes in biopsies and incidence paralleled changes in PSA screening in men 45-84 years, while in men ≥85 years biopsy rates stabilised, and incidence fell. Prostate cancer mortality in men aged 45-74 years remained low throughout. Mortality in men 75-84 years gradually increased until mid 1990s, then gradually decreased. Mortality in men ≥ 85 years increased until mid 1990s, then stabilised. CONCLUSION: Age specific prostate cancer incidence largely mirrors PSA testing rates. Most deviation from this pattern may be explained by less use of TURP in management of BPH and consequent less incidental cancer detection in TURP tissue specimens. Mortality from prostate cancer initially rose and then fell below what it was when PSA testing began. Its initial rise and fall may be explained by a possible initial tendency to over-attribute deaths of uncertain cause in older men with a diagnosis of prostate cancer to prostate cancer. Decreases in mortality rates were many fold smaller than the increases in incidence, suggesting substantial overdiagnosis of prostate cancer after introduction of PSA testing.