[957] Radical Prostatectomy (RP) Findings in Cases with Only Intraductal Carcinoma of the Prostate (IDC-P) on Needle Biopsy

BD Robinson, JI Epstein. The Johns Hopkins Hospital, Baltimore

Background: When IDC-P is present on biopsy, it is usually seen with infiltrating acinar adenocarcinoma. In 2006, we reported 27 cases with IDC-P only on biopsy; however, only 6 cases had available RP findings.
Design: 82 men with IDC-P only on prostate biopsy were identified from the consult files of one of the authors. Follow-up information was available in 66 cases. 20 men were treated with RP, 17 radiation therapy (RT), 8 hormone therapy (HT), 13 RT and HT, 6 active surveillance, and 2 rebiopsy. An attempt was made to retrieve the slides of all 20 RP cases.
Results: Of the 20 RP cases, 5 showed extraprostatic extension, 3 seminal vesicle invasion, 10 were organ-confined, and 2 showed extensive IDC-P only without identifiable invasive cancer. Of the 18 cases with invasive cancer, the average Gleason score (GS) was 7.8. 1 patient developed bone metastases 3 years post-RP, and 3 others were post-RP PSA failures. 13 RPs were available for our review. 9 showed extensive IDC-P (including one case of IDC-P only), defined as >10% of the tumor volume being intraductal; 3 focal IDC-P; and 1 no IDC-P. All cases with invasive carcinoma were acinar, although 3 cases were classified as ductal by referring pathologists. We concurred with the outside GS in 5/13 cases (5 undergraded, 3 overgraded). In the 3 cases that we gave lower GS, the outside institution graded cribiform IDC-P with and without necrosis as Gleason pattern 5 or 4, respectively.

CaseOutside GSJHH GSExtent IDCpStageRP Sampling
1IDC onlyN/AN/ATotal
2IDC onlyIDC onlyExtensiveTotal
3IDC only4+5=9Extensive2Partial

Conclusions: Our study, the largest to date with RP findings following IDC-P only on needle biopsy, confirms that aggressive therapy is appropriate for patients whose biopsies show only IDC-P. It is likely that the pathological findings are even worse than we report herein, as most RPs were only partially sampled. Most cases likely represent intraductal spread of high grade cancer, but some cases represent in situ acinar adenocarcinoma.
Category: Genitourinary (including renal tumors)

Tuesday, March 23, 2010 1:00 PM

Platform Session: Section A, Tuesday Afternoon


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