INTERPRETATION OF BILATERAL POSITIVE BIOPSIES IN PROSTATE-CANCER

Purpose: When 6 systematic prostate needle core biopsies are positive for cancer bilaterally, prediction of clinical cancer volume is limite d by the unpredictable presence of contralateral incidental tumors. Cr iteria were sought to improve prediction. Materials and Methods: Core cancer lengths were summed unilaterally (3 biopsies) and bilaterally ( 6) in 65 patients with bilateral positive cores. Of the patients 31 ha d true bilateral cancer spread and 34 had unilateral disease with cont ralateral incidental tumors. Results: For both groups correlation with prostatectomy cancer volume (r = 0.65, p < 0.001) was the same for th e sum of 3 ipsilateral cores as for all 6 cores. Conclusions: Core can cer length sum of 3 ipsilateral biopsies predicts the largest prostate ctomy cancer volume as well. as the bilateral sum. Contralateral biops ies do not contribute to prediction nor distinguish bilateral spread f rom contralateral incidental cancers.