Key clinical point: Data support the presence of disseminated tumor cells (DTCs) in the bone marrow of a subset of patients with prostate cancer (PCa).

Major finding: RNA-Seq analysis of the putative DTC population collected from samples above and below the threshold of 4 putative DTCs per million showed increased expression of PCa marker genes in 4 of 8 patients with localized PCa, but not the one normal donor who had the putative DTC population present.

Study details: Fluorescence-activated cell sorting was used to isolate a putative DTC population. While tumor cell content was examined by bulk cell RNA sequencing and whole-exome sequencing after whole genome amplification.