Fig. 1

Overview of the cohorts included in this study. The flowcharts depict the number of patients included in each cohort as well as exclusion criteria according to REMARK [25]. A FF_RP: 64 samples of the fresh-frozen tissue specimens fulfilled all inclusion criteria. 40 of those samples were tumor samples, and 16 were matched tumor-free samples. The remaining eight samples were tissue specimens from patients with benign prostatic hyperplasia and served as controls. B FFPE_Bx: 176 patients fulfilled all inclusion criteria. All samples were derived from FFPE biopsies. C TCGA_PRAD: Of the initial 552 samples, we included 332 samples that met our inclusion criteria. D DKFZ_RP: We downloaded the data for 130 samples from the EGA archive. Of those, we included 82 samples in our analyses. Patient characteristics of the cohorts are shown in Tables S1 and S2 (Additional file 1). BCR: biochemical recurrence; Bx: biopsy; DoD: Death of Disease; FF: fresh-frozen; FFPE: formalin-fixed paraffin-embedded; RP: radical prostatectomy; RIN:RNA integrity number