[show abstract][hide abstract] ABSTRACT: To describe a novel synchronous approach to apical dissection during robotic-assisted radical prostatectomy (RARP) which augments circumferential visual appreciation of the prostatic apex and membranous urethra anatomy, and assess its effect on apical margin positivity.
Positive surgical margins (PSM) during RP predispose to earlier biochemical recurrence, and occur most frequently at the prostatic apex. Conventional apical transection after early ligation of the dorsal venous complex (DVC) remains suboptimal, as this approach obscures visualization of the intersection between prostatic apex and membranous urethra, leading to inadvertent apical capsulotomy and eventual margin positivity. A synchronous urethral transection commenced via a retro-apical approach was adopted in 209 consecutive patients undergoing RARP by one surgeon (A.T.) between April to September 2009. The apical margin rates for this group were compared with those of 1665 previous patients who received conventional urethral transection via an anterior approach after DVC ligation. Outcomes were adjusted for differences in clinicopathological variables. All RP specimens were processed according to institutional protocols, and examined by dedicated genitourinary pathologists. The location of PSMs was identified as apex, posterior, posterolateral, bladder neck, anterior, base, or multifocal.
Patients receiving synchronous urethral transection had significantly lower apical PSM rates than the control group (1.4% vs 4.4%, P = 0.04). This marked improvement in the retro-apical group occurred despite a significantly higher incidence of aggressive cancer (≥ pT3a) documented on final specimen pathology (16% vs 10%, P = 0.027).Technical difficulty was encountered in three of 209 study patients, in whom urethral transection had to be completed using the classic anterior approach.
Improved circumferential visualization of the prostatic apex, membranous urethra and their anatomical intersection facilitates precise dissection of the apex and its surrounding neural scaffold, and optimizes membranous urethral preservation. This has significantly ameliorated apical PSM rates in patients undergoing RARP, despite having to deal with more aggressive cancer on final specimen pathology.
BJU International 04/2010; 106(9):1364-73. · 3.05 Impact Factor
[show abstract][hide abstract] ABSTRACT: To analyse consecutive cases of robotic-assisted laparoscopic prostatectomy (RALP), present the incidence of nerve-sparing-related positive surgical margins (SM+), include visual cues that might assist in smoothly changing to the robotic platform, and discuss the scientific rationale for 'intersensory integration' which might explain the 'reverse Braille' phenomenon, i.e. the ability to feel when vision is greatly enhanced, as the lack of tactile feedback during RALP is often cited as a disadvantage of robotic surgery, interfering with a surgeon's ability to make intraoperative oncological decisions.
Data from 1340 consecutive patients undergoing RALP from one institution were analysed and trends for positive posterolateral SM+ (PLSM+) were correlated with oncological variables before and after RALP. A sample of patient slides were reviewed by a extramural pathologist. Multivariate regression modelling was used to compare the projected rates of PLSM+ vs the actual rate, given the effect of a conscious effort to use visual cues. Finally, video recordings of the procedure were systematically reviewed and correlated with anatomical and histopathological images in an integrated session involving the surgeon and the pathology team.
The incidence of PLSM+ was 2.1%, which gradually declined to 1.0% in the last 100 patients. The reduction in PLSM+ occurred despite an increased rate of high-risk tumours operated on during this period. Forecasting analysis showed that the actual PLSM+ rate declined by half in the most recent 1000 patients, due to an integrated effort involving the use of visual cues during surgery. The following visual cues were considered important; appreciation of periprostatic (lateral prostatic) fascial compartments; colour and texture of the tissue; periprostatic veins as a landmark for athermal dissection; signs of inflammation; and a freely separating bloodless plane showing loose shiny areolar tissue.
Adapting to the robotic platform is easy and there is no compromise of the oncological safety of this procedure. Experienced surgeons can use visual cues to assist during nerve-sparing RALP and achieve low PLSM+ rates.
BJU International 02/2010; 106(4):528-36. · 3.05 Impact Factor
[show abstract][hide abstract] ABSTRACT: The similar appearance of renal tumor histological subtypes can complicate differential diagnoses. This problem is most notable for the chromophobe subtype of renal cell carcinoma, which can be histologically indistinguishable from oncocytoma with investigational molecular markers failing to provide reliable differentiation. KAI1 is a metastasis suppressor gene whose expression correlates inversely with the metastatic potential of most solid tumor cancer types. We tested the hypothesis that KAI1 is differentially expressed among renal tumor histological subtypes.
Immunohistochemical staining for KAI1 protein was performed in 152 nephrectomy specimens, including 48 clear cell, 35 papillary and 31 chromophobe renal cell carcinoma samples, 28 oncocytomas and 10 tumor-free kidneys. Staining was scored as none/minimal, low, moderate or high. KAI1 mRNA levels were compared by quantitative reverse transcriptase-polymerase chain reaction in an additional 22 chromophobe renal cell carcinoma and oncocytoma samples.
In all 10 tumor-free kidneys KAI1 protein was detected exclusively in distal tubule cell membranes. Of the tumor specimens KAI1 protein was absent in all papillary renal cell carcinoma specimens. It was present in only 1 of 48 clear cell renal cell carcinomas (2%) and 2 of 28 oncocytomas (7%) but only at low levels. In contrast, 27 of 31 chromophobe renal cell carcinoma specimens (87%) expressed KAI1 protein, most at moderate or high levels. The diagnostic accuracy of KAI1 immunostaining for discerning chromophobe renal cell carcinoma from oncocytoma was 90% with similar results observed at the RNA level.
KAI1 is an accurate biomarker for chromophobe renal cell carcinoma that may aid in the diagnostic differentiation of chromophobe renal cell carcinoma from oncocytoma. It remains to be determined whether KAI1 expression contributes to the low metastatic potential of chromophobe renal cell carcinoma.
The Journal of urology 04/2009; 181(5):2305-11. · 4.02 Impact Factor
[show abstract][hide abstract] ABSTRACT: Extraprostatic extension (EPE) of tumor is an important prognostic indicator that has an impact on long-term survival after radical prostatectomy. We investigated whether the prostate size has any association with the tumor volume and the incidence of EPE.
Seven hundred consecutive robot-assisted radical prostatectomy procedures performed by a single surgeon at a single center were studied. Preoperative parameters (demographic details, prostate-specific antigen (PSA) level, biopsy characteristics, and tumor volume) and the postoperative histopathologic details of the specimen (prostate volume, Gleason sum, EPE, and surgical margin status) were compared among the small prostate (< 40 cc), intermediate size (40-70 cc), and large prostate (> 70 cc) groups. Chi-square analysis was performed for comparison of groups with nominal variables while continuous variables were compared using analysis of variance. A double-sided P value of less than 0.05 was considered statistically significant.
A greater proportion of patients in the large prostate group had T(1c) tumor compared with those in the small prostate group (90.2% v 78.3%). Younger men and smaller prostates had lower preoperative PSA levels (P < 0.001). A significantly higher PSA density (0.16 v 0.07) and cancer density (0.0102 v 0.0025), however, was observed in patients with small prostates compared with those with large prostates. A total of 102 (14.6%) patients had EPE on the final pathologic analysis while 8.6% of the patients had positive surgical margins. Greater incidence of EPE was observed in the group with smaller prostates compared to those in the large prostate group (16.7% v 7.3%).
Small prostates have a higher cancer density and a greater incidence of EPE of tumor.
Journal of endourology / Endourological Society 02/2009; 23(3):383-6. · 1.75 Impact Factor
[show abstract][hide abstract] ABSTRACT: Robot-assisted radical prostatectomy is an option for surgical management of clinically localized prostate cancer. There have been theoretical concerns, however, regarding lack of anatomic data with specific relevance to robot-assisted prostatectomy, use of thermal or electrical energy during nerve sparing, and lack of tactile feedback. To address these concerns, we have revisited anatomic foundations and have incorporated a few modifications and strategies in the technique of robot-assisted prostatectomy to maximize cancer control, preserve neurovascular tissue, and emulate time-tested steps of anatomic radical prostatectomy. We present our findings about neural anatomy, modified technique, and oncologic and functional outcomes from patients who have undergone this procedure at our institution.
Journal of endourology / Endourological Society 07/2008; 22(6):1137-46. · 1.75 Impact Factor
[show abstract][hide abstract] ABSTRACT: To present early functional and oncological data for the athermal trizonal nerve-sparing technique of robotic radical prostatectomy (RP), that addresses the concerns about deviations from the principles of open RP and revisits the anatomical foundations of this surgery from the robotic perspective.
The study involved close collaboration between the Cornell Institute of Robotic Surgery in New York, USA, and the Institute of Urology at the University of Innsbruck in Austria. The cadaveric studies and standardization of the athermal technique were conducted at Innsbruck, and the technique was used in 215 patients in New York.
The athermal technique addresses concerns about the use of thermal energy and bulldog clamps during nerve sparing, and emphasizes the importance of the trizonal neural architecture. We analysed the surgical outcomes of 215 consecutive patients from January 2005. The operative duration was 120-240 min and the mean blood loss was 150 mL. In patients potent before RP the potency rate at 1 year after bilateral nerve-sparing was 87%. The overall surgical margin rate was 6.5% and positive margin rates for organ-confined cancer were 4.7%.
We describe the athermal technique of robotic RP and introduce the concept of trizonal nerve preservation. The immediate oncological and sexual outcomes were encouraging.
BJU International 05/2008; 101(8):1013-8. · 3.05 Impact Factor
[show abstract][hide abstract] ABSTRACT: Distinguishing low-grade and high-grade noninvasive papillary urothelial carcinoma based on morphologic criteria can be challenging and adjunct markers are highly desirable. Survivin, presumably an antiapoptotic protein, was previously proposed as a prognostic marker for urothelial carcinoma.
To assess interobserver variability by 2004 World Health Organization classification and the value of survivin and Ki-67 as potential markers for grading noninvasive papillary urothelial carcinoma.
Fifty-one bladder biopsies were graded blindly by 5 experienced general surgical pathologists. The protein and messenger RNA expression of survivin and Ki-67 was evaluated by immunohistochemistry and quantitative reverse transcription-polymerase chain reaction using paraffin-embedded tissue. The immunohistochemistry result was quantitatively analyzed using a computer-based color deconvolution module.
The diagnostic agreement among 5 pathologists was fair to poor, with 32% of the cases graded differently by at least 2 raters. All cases were divided into 3 groups: consensus low-grade, consensus high-grade, and indeterminate. The percentage of urothelial cells with positive survivin nuclear staining (survivin score) was significantly higher in the high-grade than in the low-grade group (P < .001). Survivin score outperformed Ki-67 in separating the high-grade group from the low-grade group and showed a significantly higher predictive accuracy for high-grade recurrence than the histologic grade. The disagreement of grading for the indeterminate group could be resolved by their survivin scores in most cases. Survivin messenger RNA level correlated well with survivin score by immunohistochemistry but was not a more discriminating marker.
Significant interobserver variability exists in grading low-grade versus high-grade papillary urothelial carcinoma. Survivin immunohistochemical staining can be a useful adjunct tool for the grading of challenging cases.
Archives of pathology & laboratory medicine 02/2008; 132(2):224-31. · 2.78 Impact Factor
[show abstract][hide abstract] ABSTRACT: The presence of estrogen and progesterone-receptor-positive stroma is well known in renal mixed epithelial and stromal tumor, cystic nephroma, and angiomyolipoma with epithelial cysts. It has been suggested that the hormone receptor positivity in mixed epithelial and stromal tumor may be etiologically related to exogenous hormone intake-a phenomenon that has become more frequent in recent years. In the past few years, we have observed such stroma in some non-neoplastic kidneys, as well as in tumor-bearing kidneys away from the tumor. Herein we present our experience with 10 such cases. In a prospective manner, whenever we noted stroma resembling that in ovaries or müllerian organs (endometrial or cervical-like) in kidneys removed for any cause, immunohistochemical stains for estrogen and progesterone receptors were performed. There were eight males and two females among the group, with ages ranging from 11 months to 71 years. In six cases, the nephrectomies were performed for a non-functional kidney, and in three for tumors (one each of chromophobe, clear cell, and acquired cystic disease-associated renal cell carcinoma). One case was a partial nephrectomy for vesico-ureteric reflux, with upper pole hydronephrosis. Such stroma was present in nine cases as a non-mass forming proliferation around dilated, frequently inflamed pelvicalyceal system and collecting ducts. In one it was present at the periphery of an acquired cystic disease-associated renal cell carcinoma, as well as around non-tumorous cysts. The only common finding in all cases was a generalized or segmental hydronephrosis, or tumor compression-related focal obstruction. The stroma was positive for estrogen receptors in all 10 cases, and for progesterone receptors in seven. Thus, estrogen- and progesterone receptor-positive stroma can be present in the kidney, not only as a component of certain tumors, but also in association with non-neoplastic conditions. Its association with obstructive changes suggests that it may represent a metaplastic change in the renal interstitial cells surrounding these obstructed epithelial structures.
Modern Pathology 02/2008; 21(1):60-5. · 5.25 Impact Factor
[show abstract][hide abstract] ABSTRACT: Recurrent gene fusions between TMPRSS2 and ETS family genes have recently been shown to occur at a high frequency in prostate cancer. In this study, we used formalin-fixed paraffin-embedded tissue and evaluated both TMPRSS2-ERG and TMPRSS2-ETV1 fusions by reverse transcription polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization (FISH). The results were correlated to overexpression of the downstream ERG and ETV1 sequences. Of 82 cases examined, TMPRSS2-ETV1 fusion was seen in only one case, by FISH. In comparison, TMPRSS2-ERG fusion was documented in 35 cases (43%) by either RT-PCR or FISH. Deletion, rather than translocation, was found to be the main mechanism for TMPRSS2-ERG gene fusion (81 vs 19%). RT-PCR and FISH results correlated well, with most positive cases resulting in overexpression of downstream ERG sequences. Several TMPRSS2-ERG fusion transcript variants were identified, most of which are predicted to encode truncated ERG proteins. Prostate cancer of Gleason's scores 6 or 7 had more frequent TMPRSS2-ERG fusions than higher-grade tumors, but this difference was not statistically significant (P=0.42). On the other hand, mucin-positive carcinomas more often harbor such gene fusions when compared to mucin-negative tumors (P=0.004). These morphological correlates, and more importantly the potential correlation of such fusions to clinical outcome and treatment responses, should be further explored.
Modern Pathology 10/2007; 20(9):921-8. · 5.25 Impact Factor
[show abstract][hide abstract] ABSTRACT: It is clear that some patients with prostate cancer require a total or partial neurovascular bundle (NVB) resection for oncologic safety to be guaranteed. Nerve grafting is an alternative for these patients to maintain erectile function; however, we report on a feasible option where the NVB is released, and both terminal nerve fibers are approximated; this is the "nerve advancement technique (NAT)."
Since 2005, a total of 215 men aged 48 to 70 years (mean 59 years) with a Sexual Health Inventory for Men (SHIM) score of 22 have undergone robotic radical prostatectomy for cancer. We selected prospectively seven men to have NAT performed because of clinical high-risk criteria (serum prostate specific antigen [PSA] concentration >20 mg/dL, Gleason score = 8, and stage cT(2c) or higher), intraoperative criteria (difficulty separating the tissues around the prostate), and evidence of extracapsular extension (ECE) on magnetic resonance imaging. We performed unilateral partial resection, nerve advancement, and, finally, end-to-end anastomosis in six patients, whereas in one patient, we did a bilateral partial excision. We analyzed the results in terms of oncologic safety (positive surgical margins and PSA) and SHIM score after 18 months of follow-up.
Pathologic examination revealed stage T3 disease in six patients; one had a positive surgical margin. Two patients are receiving salvage radiotherapy for PSA relapse, and five continue to have undetectable PSA concentrations after a median follow-up of 20 months. Five of the seven men recovered erectile potency with or without a phosphodiesterase inhibitor, and their median SHIM score is 18.
We are encouraged by the initial results of NAT. The procedure may be an alternative for men who require extensive NVB dissection. However, further experience, longer follow-up, and independent trials are necessary.
Journal of Endourology 08/2007; 21(8):830-5. · 2.07 Impact Factor
[show abstract][hide abstract] ABSTRACT: To compare gene expression profiles of chromophobe renal cell carcinoma (RCC) and benign oncocytoma, aiming at identifying differentially expressed genes.
Nine cases each of chromophobe RCC and oncocytoma were analyzed by oligonucleotide microarray. Candidate genes that showed consistent differential expression were validated by reverse transcription-PCR using 25 fresh-frozen and 15 formalin-fixed, paraffin-embedded tumor samples. Immunohistochemical analysis was also done for two selected gene products, claudin 8 and MAL2.
Unsupervised hierarchical clustering separated the chromophobe RCC and oncocytoma into two distinct groups. By a combination of data analysis approaches, we identified 11 candidate genes showing consistent differential expression between chromophobe RCC and oncocytoma. Five of these genes, AP1M2, MAL2, PROM2, PRSS8, and FLJ20171, were shown to effectively separate these two tumor groups by quantitative reverse transcription-PCR using fresh tissue samples, with similar trends seen on formalin-fixed tissues. Immunohistochemical analysis revealed selective expression of MAL2 and claudin 8 in distal renal tubules, with MAL2 antibody showing differential expression between chromophobe RCC and oncocytoma. Functional analyses suggest that genes encoding tight junction proteins and vesicular membrane trafficking proteins, normally expressed in distal nephrons, are retained in chromophobe RCC and lost or consistently down-regulated in oncocytoma, indicating that these two tumor types, believed to be both derived from distal tubules, are likely distinctive in their histogenesis.
We showed that chromophobe RCC and oncocytoma are distinguishable by mRNA expression profiles and a panel of gene products potentially useful as diagnostic markers were identified.
Clinical Cancer Research 01/2007; 12(23):6937-45. · 7.84 Impact Factor