Detection of prostate cancer in unselected young men: Prospective cohort nested within a randomised controlled trial

Objective: To investigate the feasibility of testing for prostate cancer and the prevalence and characteristics of the disease in unselected young men. Design: Prospective cohort nested within a randomised controlled trial, with two years of follow-up. Setting: Eight general practices in a UK city. Participants: 1299 unselected men aged 45-49. Intervention: Prostate biopsies for participants with a prostate specific antigen level of 1.5 ng/ml or more and the possibility of randomisation to three treatments for those with localised prostate cancer. Main outcome measures: Uptake of testing for prostate specific antigen; positive predictive value of prostate specific antigen; and prevalence of prostate cancer, TNM disease stage, and histological grade (Gleason score 6-10). Results: 442 of 1299 men agreed to be tested for prostate specific antigen (34%) and 54 (12%) had a raised level. The positive predictive value for prostate specific antigen was 21.3%. Ten cases of prostate cancer were detected (2.3%) with eight having at least two positive results in biopsy cores and three showing perineural invasion. One tumour was of high volume (cT2c), Gleason score 7, with a positive result on digital rectal examination; nine tumours were cT1c, Gleason score 6, and eight had a negative result on digital rectal examination. Five of the nine eligible participants (55%) agreed to be randomised. No biochemical disease progression occurred in two years of follow-up. Conclusions: Men younger than 50 will accept testing for prostate cancer but at a much lower rate than older men. Using an age based threshold of 1.5 ng/ml, the prevalence of prostate cancer was similar to that in older men (3.0 ng/ml threshold) and some cancers of potential clinical significance were found. Trial registration: Current Controlled Trials ISRCTN20141297.