Methodology for the at-home collection of urine samples for prostate cancer detection

Urine from patients with prostate cancer (PCa) contains gene transcripts that have been used for PCa diagnosis and prognosis. Historically, patient urine samples have been collected after a digital rectal examination of the prostate, which was thought necessary to boost the levels of prostatic secretions in the urine. We herein describe methodology that allows urine to be collected by patients at home and then posted to a laboratory for analysis. RNA yields and quality were comparable to those for post digital rectal examination urine, and there was improved sensitivity for the detection of transcripts by RT-PCR. The At-Home collection protocol has opened up the potential to perform large-scale PCa studies without the inconvenience, cost, discomfort and expense of patients having to visit the clinic. The use of a commercial preservative allowed samples to be maintained at room temperature without loss of RNA quality. Harvest of cell-free RNA using a novel high-volume vacuum extraction method increased total RNA yields, improved the detection sensitivity of prostate-cancer-specific transcripts by RT-PCR, enabled extraction of RNA from historic frozen urine samples, and allowed the harvest of sRNA. Comparisons between digital rectal examination (DRE) and non-DRE urine RNA yields and RT-PCR expression levels have demonstrated that the collection of non-DRE urine by men at home is a viable and simple option.