Prostate cancer (PCa) patients with biochemical recurrence (BCR) following curative therapy are at higher risk of distant metastasis and cancer-specific death. Assessment of aberrant DNA methylation in urine might complement currently used clinical prognostic factors and serve as non-invasive tool for early prediction of BCR after radical prostatectomy.

Promoter methylation of 7 genes was evaluated by methylation-sensitive PCR in 149 PCa tissues, 37 non-cancerous prostate tissues, and 17 benign prostatic hyperplasia (BPH) samples. Thereafter, quantitative PCR was used for DNA methylation analysis in urine of 253 PCa and 32 BPH patients.

In PCa tissue, the most frequently methylated genes were RASSF1, GSTP1, and RARB with a combined positivity identified in 85% of cases. These genes were also frequently (60%) methylated in urine of PCa patients. RASSF1 was methylated in 45% of urine samples from PCa with the intensity of methylation significantly higher in PCa than in BPH (P = 0.018). In univariate model, RASSF1 methylation and the total number of methylated genes in PCa tissues were predictive for time to BCR (P = 0.019 and P = 0.043). Moreover, in multivariate analysis, RASSF1 methylation together with pathological stage were the most significant predictors of BCR for patients with Gleason score 6 tumors when analyzed both in the tissue and urine ( P ≤ 0.001).

In our study, hypermethylation of RASSF1 in cancerous tissue and urine from PCa patients correlated with BCR after radical prostatectomy. The prognostic potential of this biomarker deserves further investigations.