Indications for ultrasound guided transition zone biopsies in the detection of prostate cancer.

Transrectal prostate ultrasound and systematic sextant biopsies have improved peripheral zone cancer diagnosis but they may miss many cancers arising in the transition zone. Biopsies directed into the transition zone have been used to detect residual prostate cancer in patients diagnosed by transurethral resection and they have been suggested as potentially useful additions to systematic sextant biopsies. To define the indications for transition zone biopsies 187 men underwent evaluation including systematic sextant biopsies and transition zone biopsies. These patients were classified into 4 categories based on clinical presentation. Category 1 included 26 men with palpable nodularity and an elevated prostate specific antigen (PSA), of whom 16 (61.5%) had positive biopsies but none was positive only in the transition zone biopsies. Category 2 consisted of 49 men with sonographic abnormalities in the transition zone, of whom 15 (30.6%) had positive biopsies, including 2 (13.3%) with only positive transition zone biopsies. Category 3 consisted of 65 men with normal rectal examination and elevated PSA level, of whom 24 (36.9%) had biopsies positive for cancer, including 8 (33.3%) with only positive transition zone biopsies. Category 4 consisted of 47 men with a clinical presentation highly suspicious of prostatic malignancy but no cancer on prior systematic sextant biopsies, of whom 17 (37.7%) had positive biopsies, including 9 (53.0%) with only positive transition zone biopsies. We conclude that transition zone biopsies are useful in patients with a high suspicion of prostate cancer and negative prior systematic sextant biopsies. Cancer can also be demonstrated in many men with a normal digital rectal examination and an elevated PSA level. Patients with transition zone abnormalities on ultrasound images or palpable nodularity do not have substantially increased cancer detection with the addition of transition zone biopsies.