Prostate cancer (PCa) is the third most common cancer in men worldwide.1 Prostate specific antigen (PSA) has been commonly used as a tumour marker for the early diagnosis and monitoring of PCa.2 For early diagnostic purposes, a PSA level of >4 ng mL–1 is considered as an indicator of suspicion of PCa. This evidence concerns the gene KLK3 and prostate carcinoma.