Role of measurement of length of intravesical prostatic protrusion with serum prostate specific antigen in the diagnosis of prostatic cancer

Background: The Prostate-specific antigen level is used to diagnose prostate cancer in last decades. However, its specificity is low in patients with a PSA level ranging from 4 to 10 ng/ml. This study aims to investigate the value of the length of intravesical prostatic protrusion (IPP) combined with serum prostate specific antigen on diagnosis of prostatic cancer (PCa). Methods: Data of 51 patients with prostate biopsy indications who came to the urology OPD at Stanley Medical College from October 2016 to July 2018 were collected. Clinical data include prostatic volume and IPP measured by TRUS and Serum PSA. Patients were divided into BPH group or PCa group based on the results of TRUS guided biopsy results. IPP, PSA Density(PSAD) in the two groups were analyzed. Their Sensitivity and specificity rate at different levels were respectively calculated to make sure the bestcut–off point in the diagnosis of PCa. Results: Among 51 cases, 15 patients had PCa and 36 patients had BPH. The PCa positive rate was 30.99%. Between PCa and BPH groups, there was statistical difference in IPP, PV and PSAD (P< 0.05). If taking IPP 7.5mm as the cut-off point, PCa can be diagnosed with highest specificity and sensitivity. Conclusion: The diagnosis of PCa in patients with tPSA ranging from 4.0 to 10.0 ng/ml, is a diagnostic ‘grey zone’. IPP and PSAD will help deciding which group of patients in the grey zone need to be investigated with prostatic biopsy. Further studies are needed for a better conclusion.