UNASSIGNED: 73 Background: Ki-67 is a robust predictive/prognostic marker in @entity263 however @entity5 heterogeneity may compromise its clinical utility when Ki-67 is determined off of prostate biopsy samples. We examined the variation of Ki-67 in prostate biopsy samples by NCCN risk groups and the location of the highest Ki-67 relative to the most dominant lesion on multiparametric (MP) MRI. METHODS: An IRB approved retrospective analysis was done on 77 consecutive @entity1 whose prostate biopsies revealed @entity5 . Using a MRI/US fusion device (Artemis), biopsy cores were obtained systematically and when MRI indicated a lesion, by targeting. Ki-67 staining was determined by a manual semi-quantitative method and reported as % of positive cells. The highest Ki-67 per @entity1 was used to determine inter-prostatic variation. Ki-67 range (highest Ki-67 minus lowest Ki-67 value) was used to determine intra-prostatic variation on a subset of 47 @entity1 with >= 2 positive biopsy cores. Ki-67 range was also used to evaluate intra-lesion variation on 31 MP MRI defined lesions with > 1 targeted positive biopsy core. The relationship of the dominant lesion (lesion with the largest @entity5 diameter) to the highest Ki-67 in the entire prostate was examined for 10 @entity1 with >= 2 distinct lesions on MP MRI. Analysis of variance (ANOVA) was used to evaluate differences between the means of NCCN-defined risk groups. RESULTS: Inter-prostatic Ki-67 mean  standard deviation (SD) values for low, intermediate and high risk @entity1 were 5.1%    3.8%, 7.4%    6.8%, and 12.0%    12.4% (ANOVA p=0.01). Intra-prostatic mean  SD Ki-67 ranges in low, intermediate, and high risk @entity1 were 2.6%    3.4%, 4.6%    6.4%, 9.5%    10.6% (ANOVA p = 0.0246). Intra-lesion mean  SD Ki-67 ranges in low, intermediate and high risk @entity1 were 1.0%  1.0%, 4.0%  4.29%, and 6.7%  11.51% (ANOVA p=0.39). The dominant lesion harbored the highest Ki-67 30% of the time. CONCLUSIONS: High risk @entity1 have significantly higher inter- and intra-prostatic Ki-67 heterogeneity profiles than @entity1 with low/intermediate risk disease. The highest Ki-67 is often not located in the dominant MRI defined lesion. This data can inform future biopsy strategies when integrating Ki-67 into clinical practice.

Quantifying the ki-67 heterogeneity profile in XXXX .

@entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'cancer'] @entity1 :: ('9606', 'Species') :: ['patients', 'patient', 'men'] @entity263 :: ('MESH:D011471', 'Disease') :: ['prostate cancer']
@entity263 :: (MESH:D011471,Disease) :: ['prostate cancer']
