Background: Trans rectal ultrasound guided prostate biopsy (TRUS) was introduced to Sri Lanka in 2002.
Objectives: 1. To study clinicopathological features of males subjected to TRUS biopsy 2. To compare estimation of tumour burden by two methods in carcinoma prostate (CaP).
Methods: 749 symptomatic males subjected to TRUS biopsy over 64 months at a single centre. Information was retrieved from case records. Tumour burden in CaP was calculated as: 1. Calculated tumour burden (CTB)--total percentage tumour in each core/total number of cores 2. Percentage positive biopsy cores (PPBC)--number of positive cores/total number of cores X 100. SPSS 15.0, student's t test and Spearman's rank correlation coefficients were used for statistical analysis.
Results: 35.2% had CaP, microacinar in type. 34.88% were poorly differentiated. CaP was frequent among older patients (P<0.00001). The prostate volume in CaP was significantly lower than in the benign group (P<0.05). Prostate specific antigen (PSA) level was significantly higher in CaP (P<0.00001). A 99.6% sensitivity and 4.7% specificity was observed at PSA of 4 ng/ml for detecting CaP. Specificity was 98% at 25.5 ng/ml, with a sensitivity of 44.4%. CTB and PPBC had similar correlations with biochemical/histological parameters of CaP and were strongly correlated (0.786).
Interpretation: Males with CaP were older, had higher PSA levels and smaller prostates. A cut off level of PSA >4 ng/ml could be used for directing symptomatic patients for TRUS biopsy to detect CaP, keeping in mind that specificity is 98% only at 25.5 ng/ml. Both CTB and PPBC could be used to calculate tumour burden in TRUS with CaP.