Comparison of Transrectal Ultrasound Guided Fine Needle Aspiration Cytology with Core Needle Biopsy in the Diagnosis of Prostate Cancer

Aim and objectives: To compare the diagnostic accuracy of transrectal ultrasound (TRUS) guided Fine Needle Aspiration Cytology (FNAC) protocols against the gold standard (TRUS guided Core Needle Biopsy {CNB}). Materials and methods: This was a prospective study of 96 patients being investigated for prostate cancer. Inclusion criteria comprised of the presence of one or more of the following: Persistently elevated Prostate Specific Antigen (PSA), abnormal Digital Rectal Examination (DRE) and abnormal prostatic imaging. Patients already on treatment for prostate cancer and those with symptomatic urinary tract infections were excluded. They all had an extended 10-aspiration TRUS –guided FNAC using a 22G Echotip Chiba needle. This was followed by an extended 10 core TRUS guided CNB using an 18G Bard Max-core biopsy gun at the same sitting. The extended protocol entailing traditional sextant aspirations/core needle biopsies as well as four laterally guided aspirations/core needle biopsies taken in the peripheral zone in the middle and base of the prostate were carried out. The cancer detection rates of FNAC and CNB protocols were determined and compared. The positive predictive value (PPV), negative predictive value (NPV), sensitivity and specificity were ascertained. P value <0.05 was taken as being statistically significant. Results: The overall cancer detection rate was 24.0%. Benign cases were reported in 71.8% of patients and 4.2% reported as suspicious. FNAC overall accuracy rate was 96.7% with PPV of 100% and NPV of 95.7%. Sensitivity and specificity were 88.5% and 100% respectively. Conclusion: FNAC was comparable with CNB in terms of diagnostic accuracy.