Abstract:
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 4ng/ml for detecting
CaP. Specificity was 98% at 25.5ng/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
>4ng/ml could be used for directing symptomatic patients
for TRUS biopsy to detect CaP, keeping in mind that
specificity is 98% only at 25.5ng/ml. Both CTB and PPBC
could be used to calculate tumour burden in TRUS with
CaP.
