COMPARISON OF MID-LOBE VERSUS LATERAL SYSTEMATIC SEXTANT BIOPSIES IN THE DETECTION OF PROSTATE-CANCER

Objective: Systematic sextant biopsies are a powerful tool in the diag nosis of prostate cancer. Interpretation of the histopathologic result s of these biopsies plays a central role in treatment decisions. This biopsy approach was originally described as sampling the prostate in t he mid-lobe, parasagittal plane at the apex, mid-gland, and base, bila terally. Morphometric analysis of prostate specimens has revealed that most clinically significant cancers are mainly located in the postero lateral aspect of the gland, not the mid-lobe. We sought to determine if cancer detection could be improved by obtaining more laterally plac ed biopsies. Materials and Methods: Forty-one patients underwent trans rectal ultrasound with mid-lobe sextant as well as lateral sextant bio psies. Biopsy specimens were evaluated for Gleason grade and length of cancer present in each core. The mid-lobe and lateral biopsy results were then compared. Results: Thirteen of 41 patients (31.7%) were foun d to have no cancer on either biopsy set. Cancer was detected by both the mid-lobe and the lateral biopsies in 19 patients (46.3%). In 6 pat ients (14.6%), only the lateral biopsies revealed cancer, and in 3 pat ients (7.3%), only the mid-lobe biopsies revealed cancer. Conclusions: Laterally-placed systematic sextant biopsies may yield an improved di agnosis rate in patients with palpable nodularity in the lateral aspec t of the prostate, patients without any palpable abnormalities but wit h elevated PSA levels, and in those patients undergoing repeat biopsie s.