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CAN MRI IMPROVE THE PREDICTIVE ABILITY OF BIOPSY IN SELECTING MEN FOR UNILATERAL HEMIABLATIVE FOCAL THERAPY?
THE JOURNAL OF UROLOGY®
Vol. 181, No. 4, Supplement, Sunday, April 26, 2009
487 BURIED PENIS REPAIR: A PENOSCROTAL ANGLE APPROACH Andrea Lynch*, Valhalla, NY; Lori Dyer, Israel Franco, Tarrytown, NY INTRODUCTION AND OBJECTIVE: The definitive etiology of the buried penis is not known. The most widely held belief is that the dartos fascia develops into an inelastic fiber that restrains the extension of an otherwise normal penis. We believe that abnormally high fixation of this fascia to the shaft causes the scrotum to ride high on the penis thereby burying it. Frequently, there is a large free-floating fat pad. The most common methods of surgical correction frequently yield an unsatisfactory cosmetic result secondary to the absence of a sufficient penoscrotal angle. To obviate this problem, we present a modified technique for the surgical repair of the buried penis. METHODS: From 1993-2006, we reviewed 183 cases of buried penis repair performed using the following method. A circumferential penile incision is made subcoronally and the penis is degloved to the penoscrotal angle. The penile skin is then split down the midline of the ventrum and abnormal fibro-fatty tissue is split aggressively to the urethra and into the scrotum. The now lowered scrotum is anchored to the penis on the ventral side by tacking the dartos fascia to Buck’s fascia at the 3 o’clock and 9 o’clock position with prolene sutures to fix the penoscrotal junction. The shaft skin is split dorsally and rotated medially to cover the shaft. The scrotum and the shaft skin are closed. RESULTS: There were no intraoperative complications. Associated findings included free-floating skin, large suprapubic fat pads, chordee, adhesions, phimosis and skin bridges. One patient required a revision and two patients had post-operative hematomas that resulted in recurrent skin trapping in one and an unsatisfactory cosmetic result in the other. CONCLUSIONS: We believe that the superior cosmetic results of this buried penis repair results from the aggressive incision of the scrotal fat, allowing for recession of the scrotum and recreation of the penoscrotal angle. Source of Funding: None
Prostate Cancer: Localized (I) Podium 14 Sunday, April 26, 2009
1:00 pm - 3:00 pm
488 CLINICAL PREDICTORS OF INSIGNIFICANT PROSTATE CANCER: CONTEMPORARY ANALYSIS OF EPSTEIN’S CRITERIA Michael C Lee*, Fei Dong, Alywn M Reuther, Andrew J Stephenson, J Stephen Jones, Eric A Klein, Cleveland, OH INTRODUCTION AND OBJECTIVE: Epstein’s Criteria (PSA density (PSAD) less than 0.15ng/mL, less than 3 positive biopsy cores, 50% or less of any core involved and a Gleason score of 6 or lower) identifies patients with insignificant prostate cancer (CaP). We independently assessed preoperative characteristics of patients with insignificant disease on post-radical prostatectomy (RRP) specimens in a contemporary population. METHODS: From October 1999 to January 2007, 268 men with biopsy Gleason 6 disease underwent both prostate biopsy and RRP at Cleveland Clinic. Defining insignificant cancer in the specimen as Gleason 6, low volume (< 0.5cc) and organ confined with negative margins, we performed univariate and multivariate analysis on preoperative characteristics including age, race, clinical T-stage, prostate volume, PSA, PSAD, percentage of core involvement, number of positive biopsy cores. We then evaluated the ability of Epstein’s Criteria to predict insignificant cancer in two definitions including organ-confined with tumor volume less than 0.5mL and Gleason 6 or less (classic) and then organ-confined with Gleason 6 or less (liberal). Furthermore, we included endpoints of organconfined disease on prostatectomy specimen and overall survival. RESULTS: PSAD and percentage of core involvement were found
175
to be independent predictors of insignificant CaP in multivariate analysis. The preoperative model to predict both definitions of insignificant CaP (classic and liberal) showed positive predictive values of 36.8% and 58.1% respectively. Utilizing Epstein’s Criteria as a pre-operative model for organ-confined disease, the positive predictive value was 92.6%. Kaplan-Meier curves to 6 years for those meeting Epstein’s Criteria demonstrate one- and five-year survival rates of 100% and 100% versus 98% and 83% for those not meeting Epstein’s Criteria. CONCLUSIONS: In a contemporary prostate cancer population, Epstein’s Criteria did not provide an accurate means to predict insignificant CaP and patients suitable for an active surveillance protocol. Our data stresses the need for better markers beyond baseline characteristics to identify patients with insignificant disease. Epstein’s criteria can identify men in which definitive surgical therapy can offer cure from CaP. Source of Funding: None
489 THE NUMBER OF BIOPSY CORES REPRESENTS ONE OF THE FOREMOST PREDICTOR OF CLINICALLY SIGNIFICANT GLEASON SUM UPGRADING IN LOW RISK PROSTATE CANCER PATIENTS Umberto Capitanio*, Milan, Italy; Claudio Jeldres, Hendrik Isbarn, Montreal, QCCanada; Andrea Gallina, Nazareno Suardi, Alberto Briganti, Vincenzo Scattoni, Vincenzo Roscigno, Francesco Montorsi, Milan, Italy; Pierre I Karakiewicz, Montreal, QC, Canada INTRODUCTION AND OBJECTIVE: We examined the effect of the number of biopsy cores taken on the rate of clinically significant Gleason sum upgrading (GSU) in patients with low risk prostate cancer (PCa). METHODS: We analyzed 301 patients with low risk PCa (clinical stage T1c-T2a, PSAa10 and biopsy Gleason a6) who underwent an extended (q10 cores) biopsy scheme. PSA, clinical stage, biopsy Gleason, prostate volume, year of diagnosis, number of biopsy cores and number of positive cores were used as predictors in logistic regression models addressing the rate of clinically significant GSU (defined as upgrading of biopsy Gleason 5-6 to a radical prostatectomy Gleason sum q7). The regression coefficients were used to estimate the predictive accuracy of individual variables, as well as their combined effect in the prediction of GSU. RESULTS: The median number of biopsy cores taken was 18. Upgrading was recorded in 96 (31.9%). In men assessed with 10-12 cores, the rate of GSU was 47.9% vs. 23.5% if more than 18 cores were taken (p<0.001). In multivariable analyses, the consideration of the variable defining the number of cores added 9.0% (p<0.001) to the ability to predict GSU. CONCLUSIONS: Low risk PCa patients assessed with fewer biopsy cores are at a substantial higher risk of GSU. The number of biopsy cores taken represents one of the foremost predictors of GSU and should be taken in consideration during clinical decision making in patients candidate to watchful waiting, active surveillance or brachytherapy. Source of Funding: None
490 CAN MRI IMPROVE THE PREDICTIVE ABILITY OF BIOPSY IN SELECTING MEN FOR UNILATERAL HEMIABLATIVE FOCAL THERAPY? Basir Tareen*, Timothy Ito, Guilherme Godoy, Bachir Taouli, Samir S Taneja, New York, NY INTRODUCTION AND OBJECTIVE: Focal therapy has been proposed as a means of reducing sexual and urinary morbidity associated with whole gland therapies (radical prostatectomy or radiation) while still eradicating disease. Standard transrectal ultrasound guided biopsy has been shown to be inaccurate in predicting unilateral disease. We undertook this pilot study to assess the ability of MRI to aid biopsy in predicting unilateral prostate cancer. METHODS: Between January 2007 and January 2008 we
176
THE JOURNAL OF UROLOGY®
Vol. 181, No. 4, Supplement, Sunday, April 26, 2009
identified 41 patients from our prospective radical prostatectomy database that had MRI performed at our institution prior to surgery. MRIs were retrospectively reviewed by 1 blinded radiologist and re-interpreted with respect to localizing prostate cancer to one, both, or neither lobes of the prostate. Disease at the midline was classified as bilateral. Patients predicted to have unilateral disease on biopsy were identified and biopsy and MRI data for these patients was compared with RP pathologic reports analyzing each lobe individually. The data was further analyzed with patients subdivided into low risk (PSA<10, clinical stage T1c or T2a, and Gleason score 6 on biopsy) and very low risk (low risk, with biopsy tumor volume a5%) groups. RESULTS: Of the 41 patients included in the study, 15 had unilateral disease on biopsy, 10 in the low risk group and 5 in the very low risk group. MRI alone demonstrated improved sensitivity and negative predictive value over biopsy alone (sensitivity 91% vs 65.2%; NPV 71.4% vs 46.7% respectively). When combined, MRI and biopsy demonstrated a sensitivity and negative predictive value of 100%. Risk stratification based on biopsy results demonstrated the same sensitivity and similar negative predictive value (60% vs. 66.7%) for both low risk and very low risk patients, respectively. CONCLUSIONS: This small pilot study suggests that MRI may be used as a diagnostic tool for improving the ability of biopsy for selecting candidates for hemiablative focal therapy. Large scale prospective studies analyzing the utility of MRI in this capacity are warranted. Predicting unilateral disease in patients with unilateral positive biopsy Value/Modality
Bx alone
MRI alone
Bx + MRI
Sensitivity (%)
65.2
91.3
100
Specificity (%)
100
71.4
71.4
PPV (%)
100
91.3
92
NPV (%)
46.7
71.4
100
PPV= positive predictive value; NPV= negative predictive value; Bx=biopsy; MRI= magnetic resonance i
Source of Funding: None
491 THE ROLE OF TUMOR FOCALITY IN PROSTATE CANCER FOR THE SELECTION OF PATIENTS FOR FOCAL THERAPY. Markos Karavitakis*, Hashim Uddin Ahmed, Naomi Livni, Ian Beckley, Matt Winkler, Paul Abel, London, United Kingdom INTRODUCTION AND OBJECTIVE: Focal therapy has recently been proposed as a new strategy to treat low-intermediate risk prostate cancer (PCa). However, the traditionally held view that most PCa are multifocal remains a possible impediment to its application in the majority of cases. It has been suggested that in multifocal disease focal therapy could target only the largest (index) lesion, because since secondary tumors are small unlikely to contribute to disease outcome. The objective of this study was to evaluate the role of PCa focality in selecting men for focal therapy. METHODS: 100 consecutives cases of whole mount radical prostatectomy samples were evaluated (01/07/2001 to 30/10/2003). Pathology review evaluated number of tumor foci, overall Gleason score (GsS), Gleason score (GsF) and volume (TFV) for each individual focus, total tumor volume (TTV), extracapsular extension (ECE) and seminal vesicle invasion (SVI). The index lesion was defined as the largest by volume. Patients suitable for focal ablation were defined as either having: a)unifocal, organ confined PCa , GsS<7 or; b)multifocal PCa (pT2, GsS<7) with one large index lesion and the remaining foci demonstrating features of clinically insignificant disease (TFV of all secondary foci < 0.5cc with GsF<6). RESULTS: In total, 270 tumour foci were identified. Tumors were more often multifocal (78%). There was no significant difference between unifocal and multifocal tumors with respect to total tumor volume (median 3.45cc vs 2.24cc; p=0.39), proportion of GsS>7 (30.7% vs 31.8%; p=0.9) and proportion of locally advanced disease (31.8% vs 21.79%; p= 0.33). In multifocal disease, TTV, GsS, ECE and SVI of the tumor were almost
invariably defined by the index lesion. Of the 170 secondary foci, 147 (86.4%) had volume <0.5cc and 169 (99.4%) had Gleason <6. Using the defined criteria, 51 (51%) men in this series could be considered suitable for focal ablation of the index lesion. CONCLUSIONS: Although multiple cancer foci within the prostate gland is a common feature in RP specimens, histological features of poor prognosis are arguably associated with the index lesion. Secondary foci are typically small volume and well differentiated. This is the first report from a UK cohort demonstrating tumor focality and a relationship between volume and Gleason score. Focal therapy may be suitable in a significant proportion of men currently undergoing radical surgery. Further prospective IRB approved trials are needed to evaluate the role of focal therapy which seeks to ablate only the index lesion. Source of Funding: None
492 PATHOLOGIC CHARACTERISTICS OF CONTRALATERAL PROSTATE CANCER AMONG PATIENTS WITH A SINGLE POSITIVE CORE BIOPSY Christopher R Knopick*, Theodore D Barber, Vaishali Pansare, Wael Sakr, Michael L Cher, Detroit, MI INTRODUCTION AND OBJECTIVE: Men with localized prostate cancer are typically managed with total-gland treatment such as prostatectomy or radiation. With the advent of image-guided, tissue ablative techniques, interest in focal treatment has increased. In appropriately chosen men, the goal is to destroy clinically significant cancer while reducing treatment related side-effects. We theorized that men with small volumes of low grade cancer in one core might be good candidates for unilateral ablation. To determine the pathologic characteristics of the gland in this group of men, we examined radical prostatectomy specimens. METHODS: Among men who underwent ultrasound guided biopsy (6-12 cores) between 1999 and 2004, we identified 129 cases in which <40% or a5mm of one core was positive for adenocarcinoma with Gleason sum a6. Of these patients, 46 (36%) underwent RP. We performed a detailed pathologic mapping of the resected gland including measurement of tumor volume (vol) of individual foci, grade, multifocality, and laterality with respect to the positive biopsy. RESULTS: Among the 46 patients, one (2%) had no evidence of residual carcinoma. The average total tumor vol in the remaining 45 specimens was 0.94cc (range 0.002-6.7cc). Overall, 22% of cases were “upgraded” to Gleason pattern q4 in the RP specimen. Only 22% of cases had complete absence of contralateral (CL) tumor. Also, the largest individual tumor focus was ipsilateral (IP) to the positive biopsy core in only 57% of cases. CL tumor comprised 39% of total tumor burden on average. The average vol of the largest CL tumor focus was 0.38cc (range 0-3.4cc) compared with a largest IP focus of 0.5cc (0.0008-3.1cc). 47% of patients had multifocal CL tumor (avg 1.62 foci), comparable to the IP side (1.93 foci). Additionally, the largest tumor focus was CL in 43%. A component of CL high (q4) Gleason grade was seen in 18 % of cases. Of these 8 cases 2 had bilateral high grade foci. CONCLUSIONS: Although men with a single positive biopsy tend to have low tumor volumes, approximately 80% have CL tumor. In addition, needle biopsies cannot be used to predict which side has more cancer. Although the IP and CL tumors tend to be small, there was substantial multifocality and range of cancer focus size. Approximately 20% of CL tumors had a component of high grade disease. These data show that a strategy of 6-12 core biopsies is insufficient to rule out significant contralateral cancer. This information needs to be considered by physicians and patients when entertaining the option of subtotal prostate ablation. Source of Funding: None
Vol. 181, No. 4, Supplement, Sunday, April 26, 2009
487 BURIED PENIS REPAIR: A PENOSCROTAL ANGLE APPROACH Andrea Lynch*, Valhalla, NY; Lori Dyer, Israel Franco, Tarrytown, NY INTRODUCTION AND OBJECTIVE: The definitive etiology of the buried penis is not known. The most widely held belief is that the dartos fascia develops into an inelastic fiber that restrains the extension of an otherwise normal penis. We believe that abnormally high fixation of this fascia to the shaft causes the scrotum to ride high on the penis thereby burying it. Frequently, there is a large free-floating fat pad. The most common methods of surgical correction frequently yield an unsatisfactory cosmetic result secondary to the absence of a sufficient penoscrotal angle. To obviate this problem, we present a modified technique for the surgical repair of the buried penis. METHODS: From 1993-2006, we reviewed 183 cases of buried penis repair performed using the following method. A circumferential penile incision is made subcoronally and the penis is degloved to the penoscrotal angle. The penile skin is then split down the midline of the ventrum and abnormal fibro-fatty tissue is split aggressively to the urethra and into the scrotum. The now lowered scrotum is anchored to the penis on the ventral side by tacking the dartos fascia to Buck’s fascia at the 3 o’clock and 9 o’clock position with prolene sutures to fix the penoscrotal junction. The shaft skin is split dorsally and rotated medially to cover the shaft. The scrotum and the shaft skin are closed. RESULTS: There were no intraoperative complications. Associated findings included free-floating skin, large suprapubic fat pads, chordee, adhesions, phimosis and skin bridges. One patient required a revision and two patients had post-operative hematomas that resulted in recurrent skin trapping in one and an unsatisfactory cosmetic result in the other. CONCLUSIONS: We believe that the superior cosmetic results of this buried penis repair results from the aggressive incision of the scrotal fat, allowing for recession of the scrotum and recreation of the penoscrotal angle. Source of Funding: None
Prostate Cancer: Localized (I) Podium 14 Sunday, April 26, 2009
1:00 pm - 3:00 pm
488 CLINICAL PREDICTORS OF INSIGNIFICANT PROSTATE CANCER: CONTEMPORARY ANALYSIS OF EPSTEIN’S CRITERIA Michael C Lee*, Fei Dong, Alywn M Reuther, Andrew J Stephenson, J Stephen Jones, Eric A Klein, Cleveland, OH INTRODUCTION AND OBJECTIVE: Epstein’s Criteria (PSA density (PSAD) less than 0.15ng/mL, less than 3 positive biopsy cores, 50% or less of any core involved and a Gleason score of 6 or lower) identifies patients with insignificant prostate cancer (CaP). We independently assessed preoperative characteristics of patients with insignificant disease on post-radical prostatectomy (RRP) specimens in a contemporary population. METHODS: From October 1999 to January 2007, 268 men with biopsy Gleason 6 disease underwent both prostate biopsy and RRP at Cleveland Clinic. Defining insignificant cancer in the specimen as Gleason 6, low volume (< 0.5cc) and organ confined with negative margins, we performed univariate and multivariate analysis on preoperative characteristics including age, race, clinical T-stage, prostate volume, PSA, PSAD, percentage of core involvement, number of positive biopsy cores. We then evaluated the ability of Epstein’s Criteria to predict insignificant cancer in two definitions including organ-confined with tumor volume less than 0.5mL and Gleason 6 or less (classic) and then organ-confined with Gleason 6 or less (liberal). Furthermore, we included endpoints of organconfined disease on prostatectomy specimen and overall survival. RESULTS: PSAD and percentage of core involvement were found
175
to be independent predictors of insignificant CaP in multivariate analysis. The preoperative model to predict both definitions of insignificant CaP (classic and liberal) showed positive predictive values of 36.8% and 58.1% respectively. Utilizing Epstein’s Criteria as a pre-operative model for organ-confined disease, the positive predictive value was 92.6%. Kaplan-Meier curves to 6 years for those meeting Epstein’s Criteria demonstrate one- and five-year survival rates of 100% and 100% versus 98% and 83% for those not meeting Epstein’s Criteria. CONCLUSIONS: In a contemporary prostate cancer population, Epstein’s Criteria did not provide an accurate means to predict insignificant CaP and patients suitable for an active surveillance protocol. Our data stresses the need for better markers beyond baseline characteristics to identify patients with insignificant disease. Epstein’s criteria can identify men in which definitive surgical therapy can offer cure from CaP. Source of Funding: None
489 THE NUMBER OF BIOPSY CORES REPRESENTS ONE OF THE FOREMOST PREDICTOR OF CLINICALLY SIGNIFICANT GLEASON SUM UPGRADING IN LOW RISK PROSTATE CANCER PATIENTS Umberto Capitanio*, Milan, Italy; Claudio Jeldres, Hendrik Isbarn, Montreal, QCCanada; Andrea Gallina, Nazareno Suardi, Alberto Briganti, Vincenzo Scattoni, Vincenzo Roscigno, Francesco Montorsi, Milan, Italy; Pierre I Karakiewicz, Montreal, QC, Canada INTRODUCTION AND OBJECTIVE: We examined the effect of the number of biopsy cores taken on the rate of clinically significant Gleason sum upgrading (GSU) in patients with low risk prostate cancer (PCa). METHODS: We analyzed 301 patients with low risk PCa (clinical stage T1c-T2a, PSAa10 and biopsy Gleason a6) who underwent an extended (q10 cores) biopsy scheme. PSA, clinical stage, biopsy Gleason, prostate volume, year of diagnosis, number of biopsy cores and number of positive cores were used as predictors in logistic regression models addressing the rate of clinically significant GSU (defined as upgrading of biopsy Gleason 5-6 to a radical prostatectomy Gleason sum q7). The regression coefficients were used to estimate the predictive accuracy of individual variables, as well as their combined effect in the prediction of GSU. RESULTS: The median number of biopsy cores taken was 18. Upgrading was recorded in 96 (31.9%). In men assessed with 10-12 cores, the rate of GSU was 47.9% vs. 23.5% if more than 18 cores were taken (p<0.001). In multivariable analyses, the consideration of the variable defining the number of cores added 9.0% (p<0.001) to the ability to predict GSU. CONCLUSIONS: Low risk PCa patients assessed with fewer biopsy cores are at a substantial higher risk of GSU. The number of biopsy cores taken represents one of the foremost predictors of GSU and should be taken in consideration during clinical decision making in patients candidate to watchful waiting, active surveillance or brachytherapy. Source of Funding: None
490 CAN MRI IMPROVE THE PREDICTIVE ABILITY OF BIOPSY IN SELECTING MEN FOR UNILATERAL HEMIABLATIVE FOCAL THERAPY? Basir Tareen*, Timothy Ito, Guilherme Godoy, Bachir Taouli, Samir S Taneja, New York, NY INTRODUCTION AND OBJECTIVE: Focal therapy has been proposed as a means of reducing sexual and urinary morbidity associated with whole gland therapies (radical prostatectomy or radiation) while still eradicating disease. Standard transrectal ultrasound guided biopsy has been shown to be inaccurate in predicting unilateral disease. We undertook this pilot study to assess the ability of MRI to aid biopsy in predicting unilateral prostate cancer. METHODS: Between January 2007 and January 2008 we
176
THE JOURNAL OF UROLOGY®
Vol. 181, No. 4, Supplement, Sunday, April 26, 2009
identified 41 patients from our prospective radical prostatectomy database that had MRI performed at our institution prior to surgery. MRIs were retrospectively reviewed by 1 blinded radiologist and re-interpreted with respect to localizing prostate cancer to one, both, or neither lobes of the prostate. Disease at the midline was classified as bilateral. Patients predicted to have unilateral disease on biopsy were identified and biopsy and MRI data for these patients was compared with RP pathologic reports analyzing each lobe individually. The data was further analyzed with patients subdivided into low risk (PSA<10, clinical stage T1c or T2a, and Gleason score 6 on biopsy) and very low risk (low risk, with biopsy tumor volume a5%) groups. RESULTS: Of the 41 patients included in the study, 15 had unilateral disease on biopsy, 10 in the low risk group and 5 in the very low risk group. MRI alone demonstrated improved sensitivity and negative predictive value over biopsy alone (sensitivity 91% vs 65.2%; NPV 71.4% vs 46.7% respectively). When combined, MRI and biopsy demonstrated a sensitivity and negative predictive value of 100%. Risk stratification based on biopsy results demonstrated the same sensitivity and similar negative predictive value (60% vs. 66.7%) for both low risk and very low risk patients, respectively. CONCLUSIONS: This small pilot study suggests that MRI may be used as a diagnostic tool for improving the ability of biopsy for selecting candidates for hemiablative focal therapy. Large scale prospective studies analyzing the utility of MRI in this capacity are warranted. Predicting unilateral disease in patients with unilateral positive biopsy Value/Modality
Bx alone
MRI alone
Bx + MRI
Sensitivity (%)
65.2
91.3
100
Specificity (%)
100
71.4
71.4
PPV (%)
100
91.3
92
NPV (%)
46.7
71.4
100
PPV= positive predictive value; NPV= negative predictive value; Bx=biopsy; MRI= magnetic resonance i
Source of Funding: None
491 THE ROLE OF TUMOR FOCALITY IN PROSTATE CANCER FOR THE SELECTION OF PATIENTS FOR FOCAL THERAPY. Markos Karavitakis*, Hashim Uddin Ahmed, Naomi Livni, Ian Beckley, Matt Winkler, Paul Abel, London, United Kingdom INTRODUCTION AND OBJECTIVE: Focal therapy has recently been proposed as a new strategy to treat low-intermediate risk prostate cancer (PCa). However, the traditionally held view that most PCa are multifocal remains a possible impediment to its application in the majority of cases. It has been suggested that in multifocal disease focal therapy could target only the largest (index) lesion, because since secondary tumors are small unlikely to contribute to disease outcome. The objective of this study was to evaluate the role of PCa focality in selecting men for focal therapy. METHODS: 100 consecutives cases of whole mount radical prostatectomy samples were evaluated (01/07/2001 to 30/10/2003). Pathology review evaluated number of tumor foci, overall Gleason score (GsS), Gleason score (GsF) and volume (TFV) for each individual focus, total tumor volume (TTV), extracapsular extension (ECE) and seminal vesicle invasion (SVI). The index lesion was defined as the largest by volume. Patients suitable for focal ablation were defined as either having: a)unifocal, organ confined PCa , GsS<7 or; b)multifocal PCa (pT2, GsS<7) with one large index lesion and the remaining foci demonstrating features of clinically insignificant disease (TFV of all secondary foci < 0.5cc with GsF<6). RESULTS: In total, 270 tumour foci were identified. Tumors were more often multifocal (78%). There was no significant difference between unifocal and multifocal tumors with respect to total tumor volume (median 3.45cc vs 2.24cc; p=0.39), proportion of GsS>7 (30.7% vs 31.8%; p=0.9) and proportion of locally advanced disease (31.8% vs 21.79%; p= 0.33). In multifocal disease, TTV, GsS, ECE and SVI of the tumor were almost
invariably defined by the index lesion. Of the 170 secondary foci, 147 (86.4%) had volume <0.5cc and 169 (99.4%) had Gleason <6. Using the defined criteria, 51 (51%) men in this series could be considered suitable for focal ablation of the index lesion. CONCLUSIONS: Although multiple cancer foci within the prostate gland is a common feature in RP specimens, histological features of poor prognosis are arguably associated with the index lesion. Secondary foci are typically small volume and well differentiated. This is the first report from a UK cohort demonstrating tumor focality and a relationship between volume and Gleason score. Focal therapy may be suitable in a significant proportion of men currently undergoing radical surgery. Further prospective IRB approved trials are needed to evaluate the role of focal therapy which seeks to ablate only the index lesion. Source of Funding: None
492 PATHOLOGIC CHARACTERISTICS OF CONTRALATERAL PROSTATE CANCER AMONG PATIENTS WITH A SINGLE POSITIVE CORE BIOPSY Christopher R Knopick*, Theodore D Barber, Vaishali Pansare, Wael Sakr, Michael L Cher, Detroit, MI INTRODUCTION AND OBJECTIVE: Men with localized prostate cancer are typically managed with total-gland treatment such as prostatectomy or radiation. With the advent of image-guided, tissue ablative techniques, interest in focal treatment has increased. In appropriately chosen men, the goal is to destroy clinically significant cancer while reducing treatment related side-effects. We theorized that men with small volumes of low grade cancer in one core might be good candidates for unilateral ablation. To determine the pathologic characteristics of the gland in this group of men, we examined radical prostatectomy specimens. METHODS: Among men who underwent ultrasound guided biopsy (6-12 cores) between 1999 and 2004, we identified 129 cases in which <40% or a5mm of one core was positive for adenocarcinoma with Gleason sum a6. Of these patients, 46 (36%) underwent RP. We performed a detailed pathologic mapping of the resected gland including measurement of tumor volume (vol) of individual foci, grade, multifocality, and laterality with respect to the positive biopsy. RESULTS: Among the 46 patients, one (2%) had no evidence of residual carcinoma. The average total tumor vol in the remaining 45 specimens was 0.94cc (range 0.002-6.7cc). Overall, 22% of cases were “upgraded” to Gleason pattern q4 in the RP specimen. Only 22% of cases had complete absence of contralateral (CL) tumor. Also, the largest individual tumor focus was ipsilateral (IP) to the positive biopsy core in only 57% of cases. CL tumor comprised 39% of total tumor burden on average. The average vol of the largest CL tumor focus was 0.38cc (range 0-3.4cc) compared with a largest IP focus of 0.5cc (0.0008-3.1cc). 47% of patients had multifocal CL tumor (avg 1.62 foci), comparable to the IP side (1.93 foci). Additionally, the largest tumor focus was CL in 43%. A component of CL high (q4) Gleason grade was seen in 18 % of cases. Of these 8 cases 2 had bilateral high grade foci. CONCLUSIONS: Although men with a single positive biopsy tend to have low tumor volumes, approximately 80% have CL tumor. In addition, needle biopsies cannot be used to predict which side has more cancer. Although the IP and CL tumors tend to be small, there was substantial multifocality and range of cancer focus size. Approximately 20% of CL tumors had a component of high grade disease. These data show that a strategy of 6-12 core biopsies is insufficient to rule out significant contralateral cancer. This information needs to be considered by physicians and patients when entertaining the option of subtotal prostate ablation. Source of Funding: None