Randomized-controlled Trial: Whether Transperineal Prostate Biopsy Under Local-anaesthesia Using a Transperineal-access System is Non-inferior to Standard Transrectal Biopsy to Detect Prostate Cancer in Biopsy-naïve Men

The incidence of prostate cancer (PCa) has increased considerably in recent years [1, 2]. The reported lifetime risk for men in Hong Kong to be diagnosed with PCa is 1 in 31 before the age of 75, and is currently the third commonest cancer Hong Kong men according to the Hong Kong Cancer Registry [3]. This highlights the importance of thorough and fundamentally a safe investigation technique to correctly identify patients with PCa. Such test should be able to sensitively detect PCa, and provide early diagnosis. Critically, such test is required to provide accurate disease risk stratification, which is absolutely crucial in guiding level of appropriate treatment is necessary in patients diagnosed with PCa.

According to recommendations from the National Institute for Health and Care Excellence (NICE) guidelines, current standard clinical practice considers histological diagnosis of PCa a necessity in majority of patients presented with localized disease who are eligible for treatment [4]. This, alongside with prostate specific antigen (PSA) level, digital rectal examination (DRE) findings, and increasingly the use of multi-parametric MRI (mpMRI) imaging, collectively allows risk stratification of PCa.

The current pathway to obtain prostate tissue for histological diagnosis of CaP is by transrectal ultrasound-guided systematic biopsy (TRUSB) of the prostate, usually following the detection of a raised serum PSA level and/or suspicious rectal examination findings. TRUSB has been the standard prostate tissue sampling technique for men suspected with PCa for over 30 years. It is an office-based procedure carried out under local anaesthesia (LA), with 10 to 12 biopsy cores directed towards the lateral peripheral zones of the prostate thought to harbour majority of cancers [7]. However, there are still various well-known cancer detection limitations and patient safety problems associated with TRUSB.

Firstly, a very significant portion of tumours are being missed with the TRUSB technique [8]. It has been well- known that over 30% of patients with low risk PCa on TRUSB have been found to harbour clinically significant PCa [9]. Many of these tumours missed on TRUSB are located in the anterior and apical regions of the prostate, which TRUSB is difficult to access, in particular in patients with a large prostate volume

Secondly, TRUSB requires the biopsy needle to penetrate through the bowel (rectum). This results in high risk of developing sepsis following biopsy, despite all patients undergoing the procedure being started on antibiotics prophylactically. This is a serious complication which can potentially be life-threatening. Our previous study has already demonstrated a high prevalence of fluoroquinolone-resistant and ESBL-producing rectal flora in our local population in Hong Kong [10]. The risk of developing post-biopsy sepsis in Hong Kong is high.