Men under the age of 55 years with screen detected prostate cancer do not have less significant disease compared to older men in a population of patients in Australia

Nandu D. Dantanarayana, Tania Hossack, Paul Cozzi, Andrew Brooks, Howard Lau, Warick Delprado, Manish I. Patel

The American Urological Association (AUA) changed their Prostate-Specific Antigen (PSA) screening guidelines in 2013 to not recommend testing in men under 55 years of age without significant risk factors (such as a family history of prostate cancer or African ethnicity). The AUA argues that the rates of 'insignificant' prostate cancer (PC) in men under 55 are so high that the potential harms of PSA-testing in this population (over diagnosis and overtreatment) outweigh the benefits (early detection and treatment). Our study aims to identify and compare the rates of insignificant and high-risk PC in men diagnosed with PC ≤55 years and >55 years in two centres in Sydney, Australia. Men with an abnormal screening PSA or DRE and diagnosed with PC by prostate biopsy were included in this study. A consecutive series of men were accrued from two major urology centres between the years 2006 and 2014. The analysis was divided into two parts, the first compared PC biopsy characteristics between men aged ≤55 years and those >55 years. The second analysis compared the prostatectomy pathological characteristics between the two groups. Differences were analysed by Chi squared and significance set at p < 0.05. A total of 598 prostate biopsies and 723 prostatectomy matched subjects were included. On prostate biopsies, 14.0 % of men ≤55 years and 11.9 % of men >55 years had insignificant PC (X(2) = 0.32, df = 1, p = 0.57), whilst 24.7 % of men ≤55 years and 25.1 % of men >55 years had high-risk PC (X(2) = 0.007, df = 1, p = 0.93). On prostatectomy specimens, 9.1 % of men ≤55 years and 6.5 % of men >55 years had insignificant PC (X(2) = 1.25, df = 1, p = 0.26), whilst 20.0 % of men ≤55 years and 24.0 % of men >55 years had high-risk PC (X(2) = 0.83, df = 1, p = 0.36). We found no significant difference in the rates of insignificant and high-risk PC between men ≤55 years and >55 years, in either the prostate biopsies or prostatectomy specimens. Further trials need to be performed with comparable sample sizes and controlling of risk factors to assess the utility of PSA screening in younger men.