Optimizing prostate cancer screening; prospective randomized controlled study of the role of PSA and PCA3 testing in a sequential manner in an opportunistic screening program.

Objectives: To reduce unnecessary biopsies (Bx) in an opportunistic screening programme of prostate cancer.

Material And Methods: We perform a prospective evaluation of PCA3 as a second line biomarker in an opportunistic screening for prostate cancer (PCa). From September-2010 until September-2012, 2,366 men, aged 40-74 years and with >10 years life expectancy, were initially screened with PSA/digital rectal examination (DRE). Men with previous Bx or with recent urine infections were excluded. Men with abnormal DRE and/or PSA >3 ng/ml were submitted for PCA3. All men with PCA3 ≥ 35 underwent an initial biopsy (IBx) -12cores-. Men with PCA3 < 35 were randomized 1:1 to either IBx or observation. Re-biopsy(16-18 cores) criteria were PSA increase >.5 ng/ml at 4-6 months or PSAv > .75 ng/ml/year.

Results: With median follow-up (FU) of 10.1 months, PCA3 was performed in 321/2366 men (13.57%), 289 at first visit and 32 during FU. All 110 PCA3+ men (34.3%) were biopsied and PCa was identified in 43 men in IBx (39.1%). In the randomized arm, 110 were observed and 101 underwent biopsy, finding 12 PCa (11.9%), showing a statistically significant reduction of PCa detection rate in this cohort (P<.001). Global PCa detection rates were 40.9% and 9.5% for the PCA3+ and PCA3- branches, respectively (P<.001). Area under the curve for PSA and PCA3 were .601 and .74, respectively. This is an ongoing prospective study limited by its short follow-up period and still limited enrolment.

Conclusions: PCA3 as a second line biomarker within an opportunistic dual screening protocol, can potentially avoid 65.7% and 50.1% biopsies at first round and at median FU of 10.1 months, respectively, just missing around 3.2% of high grade PCa.