[740] Assessment of the Aggressivenss of Ductal Adenocarcinoma (Adenoca) of the Prostate: A Radical Prostatectomy (RP) Study of 93 Cases.

Ali Amin, Jonathan I Epstein. The Johns Hopkins Hospital, Baltimore, MD

Background: It is unknown whether ductal adenoca. are more aggressive when matched for Gleason score (assigning the ductal component as Gleason pattern 4). Also, little is also known whether a certain percent of ductal component is needed to account for the more aggressive behavior.
Design: Out of 18,552 RPs performed from 1995 to 2008, 93 cases with a ductal adenoca. component were identified. Cases were classified based on their ductal/acinar ratio (1: <10%; 2: ≥10% and <50%; 3: ≥50%). There was no difference in the distribution of Gleason score 3+4=7 vs. 4+3=7 between ductal and non-ductal tumors, such that cases were combined as Gleason score 7.
Results: There was no age, race and serum PSA difference between patients with and without ductal adenoca. Cases with ductal adenoca. were less likely be organ confined (36.6% vs. 65.6%) and more likely to have seminal vesicle invasion (SVI) (19.3% vs. 5.3%), p<0.0001. There was no difference in lymph node (LN) metastases or positive margins between cases with and without ductal features. An increasing percentage of ductal component correlated with an increased risk of extra-prostatic extension (EPE) (p=0.04) and SVI (p<0.0001). To account for overall different Gleason scores between ductal and non-ductal cases as well as the affect of differing percentages of ductal features, the following analysis was done. For Gleason score 7 cases and ≥10% ductal features, cases with ductal features were more likely to have non-focal EPE (64.0%) vs. cases without ductal features (34.7%), p=0.002. In this group, there was no statistically significant difference in SVI or LN involvement between Gleason score 7 ductal and non-ductal tumors, possible due to the small number of positive events. For Gleason score 7 cases with <10% ductal features, there was no difference in pathological stage vs. non-ductal cases. There was no difference in pathological stage between ductal and non-ductal cases for Gleason score 8-10 cases, regardless of the percent ductal component or the Gleason score.
Conclusions: The current study demonstrates that ductal adenoca. admixed with Gleason pattern 3 is more aggressive than Gleason score 7 acinar cancer, as long as the ductal component is ≥10%. In cases with a very minor ductal component, these differences are lost. Also Gleason score 8-10 tumors with ductal features are not more aggressive that acinar Gleason score 8-10 cancers, where the high grade, regardless of ductal features, determines the aggressiveness.
Category: Genitourinary (including renal tumors)

Monday, February 28, 2011 1:00 PM

Poster Session II # 117, Monday Afternoon

 

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