[873] Significance of Tertiary Pattern 5 in Prostate Needle Biopsies with Gleason Score of 3+4 or 4+3 Prostate Cancer: Pathologic Correlation Following Radical Prostatectomy

RB Shah, S Daignault, LP Kunju, DP Wood, Jr, JT Wei. University of Michigan, Ann Arbor, MI

Background: The International Society of Urologic Pathologists recommends biopsy Gleason score (GS) of 3+4 or 4+3 prostate cancer (PCA) with tertiary pattern 5 be classified as GS of 8 or 9, respectively so that it can be incorporated in the current PCA nomograms for management decisions. However, the scientific data supporting this recommendation and the overall significance of tertiary pattern 5 in prostate needle biopsy (NBX) is largely unknown.
Design: Prostate NBXs with Gleason score 7 (both 3+4 and 4+3) with tertiary Gleason pattern 5 (third least common pattern of any amount recognizable at low power) were identified to determine the prognostic significance and reporting recommendation of tertiary pattern 5. For control population NBXs with GS 7 without tertiary pattern 5 and GS 8-10 were included. For all groups only those patients who underwent subsequent radical prostatectomy as a definitive treatment were included for further analysis of pathologic outcomes as an end point.
Results: Total 30 cases met the criteria. Pretreatment serum PSA ranged from 1.7 to 42 ng/ml (median 7.4). The nmber of cores sampled ranged from 6 to 14 with one to three cores involved by tertiary pattern 5. Of 30 cases, 26 underwent radical prostatectomy (RP), 2 combined radiotherapy and androgen deprivation, 1 radiation, and 1 awaiting therapy. Of 26 patients with RP, 31% were pT2, 42% T3a, 23 % T3b, 4 % T4, 19 % with lymph node metastasis and 27% had positive surgical margins. Gleason 7 with tertiary 5 were significantly more likely to present with locally advanced caners (pT3/pT4) and lymph node metastasis, compared to Gleason 7 without tertiary 5 (P 0.0001). At RP, pattern 5 was seen as primary, secondary and tertiary pattern in 4%, 42%, and 50% of biopsy GS 7 with tertiary 7 cases respectively, remaining 4% had no pattern 5.
Conclusions: Men with prostate cancer having biopsy GS 7 with a tertiary pattern 5 had a significantly high risk of adverse pathologic outcomes in comparison to biopsy GS 7 without tertiary 5. Our fundings justify the inclusion of tertiary pattern 5 in biopsy as a secondary pattern for prognostic and management decisions.
Category: Genitourinary (including renal tumors)

Wednesday, March 11, 2009 9:30 AM

Poster Session V # 120, Wednesday Morning