[925] Prognostic Significance of Patterns of Seminal Vesicle Invasion of Prostate Cancer

Anna Kristiansen, Fredrik Wiklund, Peter Wiklund, Lars Egevad. Karolinska Institutet, Stockholm, Sweden

Background: Seminal vesicle invasion (SVI) is an indicator of poor prognosis of prostate carcinoma, but the outcome varies and further stratification is needed. This study aimed to evaluate the prognostic significance of histopathological patterns of SVI after radical prostatectomy.
Design: A total of 1156 men underwent radical prostatectomy at the Karolinska Hospital from 1998 to 2005. Men with neoadjuvant treatment or TURP prior to surgery or unavailable histological slides or clinical follow-up were excluded and 1051 cases remained for review. SVI was found in 5.9% (62/1051) and intraprostatic SVI in another 2.2% (23/1051). Slides were reviewed for histopathological features including Gleason score (GS) of seminal vesicle (SV) component, bilateral vs. unilateral involvement, route of invasion (Type 1: via ejaculatory duct, Type 2: direct invasion excluding ejaculatory duct, Type 3: discontinous invasion), tumor area, largest diameters, distribution in SV (perivesicular connective tissue, muscular wall, mucosa), surgical margin status in SV and invasion of vas deferens. The association with risk for biochemical recurrence was analyzed.
Results: SVI was associated with poor prognosis (HR 1.8 [95% CI 1.2-2.8], p=0.0047) with recurrence in 40.3% (25/62), while intraprostatic SVI was not (HR 1.1 [95% CI 0.5-2.4], p=0.75). The most common route of SVI was Type 1 (83.6%), while Type 3 was found in only 2 cases. The GS of the SV component was higher than that of the main tumor in 29.5% (16/61). A GS lower than 7 in the main tumor was only seen in 2 cases and never in the SV component. Invasion of SV mucosa was seen in 66.1% (41/62) and was always accompanied by muscle wall invasion. SV mucosal invasion was strongly associated with outcome (HR 3.3 [95% CI 1.1-9.8], p=0.029), while only 20% (4/20) of men with muscle wall invasion alone experienced recurrence. Other histopathological characteristics of SVI such as measures of extent, invasion route, local margin status and local GS of the SV component did not predict outcome.
Conclusions: The prognosis of patients with SVI is not uniformly poor. Invasion of the SV mucosa portends a higher risk of recurrence than invasion of the muscle wall alone. There is no evidence that other histopathological features of SVI need to be reported.
Category: Genitourinary (including renal tumors)

Tuesday, March 20, 2012 1:45 PM

Platform Session: Section A, Tuesday Afternoon


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