A comparative study of the relevance of digital rectal examination, transrectal ultrasound, and prostate-specific antigen in the diagnostic evaluation of patients with advanced carcinoma of the prostate in a resource poor environment

Abstract

Aims: To compare the diagnostic yield of digital rectal examination (DRE), transrectal ultrasound (TRUS) scan, and prostate-specific antigen (PSA) in diagnostic evaluation of advanced carcinoma of the prostate (CAP). Subjects and Methods: A comparative study of sensitivity and specificity of DRE, TRUS, and PSA in the evaluation of advanced CAP. This was done over a 3-year period (January 2010 to December 2012) in a tertiary health institution in Sub-Saharan Africa. All patients presenting with symptoms of prostatic enlargement were recruited, DRE, TRUS, and PSA findings were compared to the histological diagnosis. Statistical Analysis Used: SPSS version 16.0. Results: One hundred and eight cases were analyzed. Histological diagnosis revealed that 52 (48.1%) were CAP whereas 56 (51.9%) were benign. All the patients presented with lower urinary tract symptoms. Surprisingly, some patients with advanced CAP had PSA values in the normal range (0-4 ng/ml) while some with the benign disease also had PSA values above 50 ng/ml. PSA was noted to have the highest sensitivity but lowest specificity. Conclusions: Limitations of PSA are not only seen in screening for early disease, but also in the diagnosis of advanced CAP, and no value of PSA can be considered safe to declare a patient CAP free.

Keywords

• Carcinoma
• diagnosis
• prostate
• screening
• ultrasound