Clinical Findings and Treatment Outcomes in Patients with Extraprostatic Extension Identified on Prostate Biopsy

Abstract

Purpose To describe the histopathological, clinical and imaging findings among men with extraprostatic extension (EPE) on prostate biopsy. Materials and methods We searched our Institutional Pathology Database, between the years 2004-2015, for pathology reports detailing EPE on prostate biopsy in untreated patients. Patient characteristics, biopsy features, imaging interpretations and outcomes were examined. Results Of 19,950 patients with prostate cancer on biopsy, 112 had EPE, a prevalence of 0.6% (95% CI 0.5%-0.7%). Most patients had palpable, high-grade (Gleason score 9), high-volume, disease classified as high-risk (30%; 34/112), locally advanced (15%; 17/112), or metastatic (35%; 39/112). Most had one or two cores with EPE, typically at the base and with concomitant perineural invasion. EPE was identified by MRI in 80% (32/40). The median follow-up for those who did not die was 1.3 years (IQR 0.3, 4.2). Outcomes for the subgroup of 24 men who had an RP were consistent with high risk disease: positive margins (58%; 14/24), SVI (42%; 10/24), and LNI (46%; 11/24). For the entire cohort, the 3-year risks of metastasis and overall mortality were 32% (95% CI 22%, 44%) and 37% (95% CI 27%, 50%), respectively. We did not find evidence to suggest that the proportion of cores with cancer that also had EPE was associated with overall mortality (p=0.09). Conclusions EPE is a rare finding on prostate biopsy. It is strongly associated with other features of aggressive prostate cancer.

Detection of extraprostatic disease and seminal vesicle invasion in patients undergoing magnetic resonance imaging-targeted prostate biopsies

“…However, due to its rarity on biopsy, little is known about biopsy detected EPE as a potential independent predictor of aggressive PCa. In a study by Fleshner et al , 112/19,950 (0.6%) patients with PCa on SB had detection of EPE ( 1 ). Overall, we found EPE and/or SVI in 1.5% of patients with PCa who had undergone TB.…”

“…Identification of EPE is an important component of staging in PCa patients, and is defined by the American Joint Committee on Cancer (AJCC) TNM staging system as pT3a in the presence of extension into the periprostatic fat and as pT3b in the case of SVI ( 1 , 15 , 16 ). Although the presence of EPE on SB is a rare occurrence, a significant number of patients who undergo radical prostatectomy for presumed localized disease are found to have EPE, implying that its presence is being consistently under detected on SB ( 15 ).…”

“…Although rare, both extraprostatic extension (EPE) and seminal vesicle invasion (SVI) by prostate cancer (PCa) can be identified on prostate needle core biopsy. In one large retrospective study, EPE was found in only 0.6% of prostate needle core biopsy cases ( 1 ). The majority of these cases were associated with perineural invasion (PNI) on standard biopsy (SB) as well as high-risk disease on follow up radical prostatectomy.…”

Clinical and oncologic findings of extraprostatic extension on needle biopsy in de novo metastatic prostate cancer

“…To date, only two studies have reported the outcomes of patients with EPE on needle biopsy. 6 7 Miller et al . 7 from John Hopkins University (JHU) reviewed 51 891 cases of prostatic adenocarcinoma from 1997 to 2009 and reported a prevalence of positive EPE on needle biopsy of 0.19%.…”

“…However, because it is relatively rarely detected, there is limited information on the clinical significance of biopsy-detected EPE in patients with PCa. 6 7 In addition, neither the detection rate of EPE in metastatic PCa (mPCa) nor its clinical outcomes have yet been reported.…”