A comparative analysis of sextant and an extended 11-core multisite directed biopsy strategy

Purpose: The 3 tumor locations unsampled by conventional sextant; biopsies that have been identified on composite 3-dimensional reconstruction of 180 radical prostatectomy specimens are the anterior transition zone, midline p eripheral zone and inferior portions of the anterior horn in the peripheral zone. We evaluated an Ii-core multisite directed biopsy scheme incorporati ng these alternate areas and conventional sextant biopsies in 362 patients from 2 institutions. Materials and Methods: Patients without a prior diagnosis of cancer underwe nt ultrasound guided Ii-core biopsies which included conventional sextant a nd 3 alternate sites. All specimens were separated for specific location id entification. Biopsy was performed in 183 patients at MD Anderson Cancer Ce nter (group 1) and in 179 at Toronto General Hospital (group 2). All group 2 and 54% of group 1 patients (98 of 183) had a prior biopsy negative for c ancer. Results: Median prostate specific antigen was higher in group 2 than in gro up 1 patients (11.5 versus 9.5 ng./ml,, p = 0.016). Overall a 33% increase (36 of 110 patients) in cancer detection was observed when biopsy technique included the alternate areas (p = 0.0021). The anterior horn was the most frequently positive biopsy site followed by the transition zone and midline sites. The Ii-core technique had significantly better cancer detection rat es when digital rectal examination and transrectal ultrasound were normal, and in men with serum prostate specific antigen between 4.1 and 10 ng./ml. Conclusions: Biopsies of the alternate sites suggested by our simulation st udies are feasible and reproducible. This new strategy significantly enhanc ed (p = 0.0075) prostate cancer detection compared to conventional sextant biopsies in men undergoing a repeat procedure.