Association of an organ transplant-based approach with a dramatic reduction in postoperative complications following radical nephrectomy and tumor thrombectomy in renal cell carcinoma

OBJECTIVES

Our aim was to determine whether using an organ transplant-based(TB) approach reduces postoperative complications(PCs) following radical nephrectomy(RN) and tumor thrombectomy(TT) in renal cell carcinoma(RCC) patients with level II-IV thrombi.

METHODS

A total of 390(292 non-TB/98 TB) IRCC-VT Consortium patients who received no preoperative embolization/IVC filter were included. Stepwise linear/logistic regression analyses were performed to determine significant multivariable predictors of intraoperative estimated blood loss(IEBL), number blood transfusions received, and overall/major PC development within 30days following surgery. Propensity to receive the TB approach was controlled.

RESULTS

The TB approach was clearly superior in limiting IEBL, blood transfusions, and PC development, even after controlling for other significant prognosticators/propensity score(P < .000001 in each case). Median IEBL for non-TB/TB approaches was 1000 cc/300 cc and 1500 cc/500 cc for tumor thrombus Level II-III patients, respectively, with no notable differences for Level IV patients(2000 cc each). In comparing PC outcomes between non-TB/TB patients with a non-Right-Atrium Cranial Limit, the observed percentage developing a: i) PC was 65.8%(133/202) vs. 4.3%(3/69) for ECOG Performance Status(ECOG-PS) 0-1, and 84.8%(28/33) vs. 25.0%(4/16) for ECOG-PS 2-4, and ii) major PC was 16.8%(34/202) vs. 1.4%(1/69) for ECOG-PS 0-1, and 27.3%(9/33) vs. 12.5%(2/16) for ECOG-PS 2-4. Major study limitation was the fact that all TB patients were treated by a single, experienced, high volume surgeon from one center (non-TB patients were treated by various surgeons at 13 other centers).

CONCLUSIONS

Despite this major study limitation, the observed dramatic differences in PC outcomes suggest that the TB approach offers a major breakthrough in limiting operative morbidity in RCC patients receiving RN and TT.

Is imperative partial nephrectomy feasible for kidney cancer with venous thrombus involvement? Outcomes of 42 cases and matched pair analysis with a large radical nephrectomy cohort

BACKGROUND

Radical nephrectomy (RN) with/without (±) thrombus excision (ThE) is the undisputed standard treatment for kidney cancer (KC) with renal or caval thrombus (Th). However, partial nephrectomy (PN) ± ThE may be considered in rare cases due to imperative (I) indications.

OBJECTIVE

To evaluate the efficacy of IPN ± ThE and to compare it with RN ± ThE for KC with Th.

DESIGN, SETTING, AND PARTICIPANTS

Records of 2,549 patients undergoing surgery for KC with Th at 24 institutions between 1971 and 2014 were retrospectively reviewed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Primary outcomes were overall survival (OS) and cancer specific survival (CSS), renal function variation after surgery and complications. Secondary outcomes were predictors of OS and CSS for IPN cases. To reduce bias IPN group was matched with RN using a propensity score with greedy algorithm on the basis of age, gender, tumor size, TNM, and histology.

RESULTS AND LIMITATIONS

Forty-two patients underwent IPN ± Th. All thrombi were ≥level I; 5 patients experienced Clavien ≥ 3 complications with 2 complications-related deaths. At 27.3 (interquartile range: 7.1-47.7) months OS and CSS were 54.8% and 78.6%, respectively whereas at 9.7 (interquartile range: 1.4-43.7) months eGFR change was -17.3 ± 27.0ml/min. On univariate analysis tumour size, preoperative eGFR, transfusions, hospital stay, high serum creatinine, operating time, complications, lymphadenectomy, and metastases related to an increased risk of death. After matching (n = 38 per arm) no significant differences were present except for tumor necrosis (IPN = 39.5%; 15.8%; P = 0.01), thrombus level (P = 0.02), so as for operating time (P = 0.27), perioperative transfusions (P = 0.74) and complications (P = 0.35). A 5-year OS and CSS for IPN were 57.9% and 73.7%, respectively with no significant differences with RN (OS = 63.2, P = 0.611; CSS = 68.4, P>0.99). After 14.9 months creatinine and eGFR changes were (+0.4 ± 0.6mg/dl and -23.2 ± 37.3ml/min; P = 0.2879).

CONCLUSIONS

In selected cases due to imperative indications PN ± ThE is a complex procedure and may be an alternative to RN ± ThE for KC with Th yielding noninferior oncological outcomes, functional outcomes, and complications. Further studies are needed to determine the role of PN ± ThE for KC with Th.

Impact of lymph node dissection at the time of radical nephrectomy with tumor thrombectomy on oncological outcomes: Results from the International Renal Cell Carcinoma-Venous Thrombus Consortium (IRCC-VTC)

OBJECTIVES

To study the effect of lymph node dissection (LND) at the time of nephrectomy and tumor thrombectomy on oncological outcomes in patients with renal cell carcinoma (RCC) and tumor thrombus.

PATIENTS AND METHODS

The records of 1,978 patients with RCC and tumor thrombus who underwent radical nephrectomy and tumor thrombectomy from 1985 to 2014 at 24 centers were analyzed. None of the patients had distant metastases. Extent and pathologic results of LND were compared with respect to cancer-specific survival (CSS). Multivariable Cox regression models were used to quantify the effect of multiple covariates.

RESULTS

LND was performed in 1,026 patients. In multivariable analysis, the presence of LN metastasis, the number of positive LNs, and LN density were independently associated with cancer-specific mortality (CSM). Clinical node-negative (cN-) disease was documented in 573 patients, 447 of them underwent LND with 43 cN- patients (9.6%) revealing positive LNs at pathology. LN positive cN- patients showed significantly better CSS when compared to LN positive cN+ patients. In multivariable analysis, positive cN status in LN positive patients was a significant predictor of CSM (HR, 2.923; P = 0.015).

CONCLUSIONS

The number of positive nodes harvested during LND and LN density was strong prognostic indicators of CSS, while number of removed LNs did not have a significant effect on CSS. The rate of pN1 patients among clinically node-negative patients was relatively high, and LND in these patients suggested a survival benefit. However, only a randomized trial can determine the absolute benefit of LND in this setting.

Renal cell carcinoma with inferior vena cava involvement: Prognostic effect of tumor thrombus consistency on cancer specific survival

BACKGROUND

Renal cell carcinoma forming a venous tumor thrombus (VTT) in the inferior vena cava (IVC) has a poor prognosis. Recent investigations have been focused on prognostic markers of survival. Thrombus consistency (TC) has been proposed to be of significant value but yet there are conflicting data. The aim of this study is to test the effect of IVC VTT consistency on cancer specific survival (CSS) in a multi-institutional cohort.

METHODS

The records of 413 patients collected by the International Renal Cell Carcinoma-Venous Thrombus Consortium were retrospectively analyzed. All patients underwent radical nephrectomy and tumor thrombectomy. Kaplan-Meier estimate and Cox regression analyses investigated the impact of TC on CSS in addition to established clinicopathological predictors.

RESULTS

VTT was solid in 225 patients and friable in 188 patients. Median CSS was 50 months in solid and 45 months in friable VTT. TC showed no significant association with metastatic spread, pT stage, perinephric fat invasion, and higher Fuhrman grade. Survival analysis and Cox regression rejected TC as prognostic marker for CSS.

CONCLUSIONS

In the largest cohort published so far, TC seems not to be independently associated with survival in RCC patients and should therefore not be included in risk stratification models. J. Surg. Oncol. 2016;114:764-768. © 2016 Wiley Periodicals, Inc.

A non-invasive miRNA based assay to detect bladder cancer in cell-free urine

RNA from cell-free urine was analyzed in an attempt to identify a microRNA (miRNA) profile that could be used as a non-invasive diagnostic assay to detect the presence of urothelial carcinoma of the bladder (UCB) and provide a discriminatory signature for different stages of progression. In addition, the presence of specific miRNAs co-isolating with urinary extracellular vesicles/exosomes was investigated. RNA was isolated from cell-free urine of patients diagnosed with UCB (TaG1, T1G3, ≥T2, CIS) and control patients (healthy control and UCB patients with no evidence of disease). MiRNAs were profiled by qRT-PCR array on pooled samples within each group. Validation of the miRNAs was performed on individual samples using qRT-PCR. Extracellular vesicles were isolated via ultracentrifugation. 236 miRNAs were detected in at least one of the pooled samples. Seven of the miRNAs validated on individual samples had significantly higher levels in the cancer group. A panel of miRNAs discriminated between cancer and cancer-free patients with a sensitivity of 88% and specificity of 78%, (AUC=88.8%). We recorded a sensitivity of 80% for TaG1, 95% for T1G3, 90% for ≥T2 with specificity of 77% for healthy controls and 80% for no evidence of disease. Select miRNAs were detected in extracellular vesicles of UCB patients and healthy controls, albeit at different levels. Utilizing this non-invasive assay, we identified miRNA capable of detecting UCB and distinguishing different stages of progression, providing evidence that miRNA profiling in cell-free urine holds promise for the development of valuable clinical diagnostic tools.

Cardiopulmonary Bypass has No Significant Impact on Survival in Patients Undergoing Nephrectomy and Level III-IV Inferior Vena Cava Thrombectomy: Multi-Institutional Analysis

PURPOSE

The impact of cardiopulmonary bypass in level III-IV tumor thrombectomy on surgical and oncologic outcomes is unknown. We determine the impact of cardiopulmonary bypass on overall and cancer specific survival, as well as surgical complication rates and immediate outcomes in patients undergoing nephrectomy and level III-IV tumor thrombectomy with or without cardiopulmonary bypass.

MATERIALS AND METHODS

We retrospectively analyzed 362 patients with renal cell cancer and with level III or IV tumor thrombus from 1992 to 2012 at 22 U.S. and European centers. Cox proportional hazards models were used to compare overall and cancer specific survival between patients with and without cardiopulmonary bypass. Perioperative mortality and complication rates were assessed using logistic regression analyses.

RESULTS

Median overall survival was 24.6 months in noncardiopulmonary bypass cases and 26.6 months in cardiopulmonary bypass cases. Overall survival and cancer specific survival did not differ significantly in both groups on univariate analysis or when adjusting for known risk factors. On multivariate analysis no significant differences were seen in hospital length of stay, Clavien 1-4 complication rate, intraoperative or 30-day mortality and cancer specific survival. Limitations include the retrospective nature of the study.

CONCLUSIONS

In our multi-institutional analysis the use of cardiopulmonary bypass did not significantly impact cancer specific survival or overall survival in patients undergoing nephrectomy and level III or IV tumor thrombectomy. Neither approach was independently associated with increased mortality on multivariate analysis. Greater surgical complications were not independently associated with the use of cardiopulmonary bypass.

MicroRNA Profile to Predict Gemcitabine Resistance in Bladder Carcinoma Cell Lines

MicroRNAs (miRNA) are small, noncoding RNAs with important regulatory roles in development, differentiation, cell proliferation, and death as well as the complex process of acquired drug resistance. The goal of this study was to identify specific miRNAs and their potential protein targets that confer acquired resistance to gemcitabine in urothelial carcinoma of the bladder (UCB) cell lines. Gemcitabine-resistant cells were established from 6 cell lines following exposure to escalating concentrations of the drug and by passaging cells in the presence of the drug over a 2- to 3-month period. Differential miRNA expression was identified in a microarray format comparing untreated controls with resistant cell lines, representing the maximum tolerated concentration, and results were validated via qRT-PCR. The involvement of specific miRNAs in chemoresistance was confirmed with transfection experiments, followed by clonogenic assays and Western blot analysis. Gemcitabine resistance was generated in 6 UCB cell lines. Microarray analysis comparing miRNA expression between gemcitabine-resistant and parental cells identified the differential expression of 66 miRNAs. Confirmation of differential expression was recorded via qRT-PCR in a subset of these miRNAs. Within this group, let-7b and let-7i exhibited decreased expression, while miR-1290 and miR-138 displayed increased expression levels in gemcitabine-resistant cells. Transfection of pre-miR-138 and pre-miR-1290 into parental cells attenuated cell death after exposure to gemcitabine, while transfection of pre-miR-let-7b and pre-miR-let-7i into the resistant cells augmented cell death. Mucin-4 was up-regulated in gemcitabine-resistant cells. Ectopic expression of let-7i and let-7b in the resistant cells resulted in the down-regulation of mucin-4. These results suggest a role for miRNAs 1290, 138, let-7i, and let-7b in imparting resistance to gemcitabine in UCB cell lines in part through the modulation of mucin-4. Alterations in these miRNAs and/or mucin-4 may constitute a potential therapeutic strategy for improving the efficacy of gemcitabine in UCB.

Impact of histologic subtype on cancer-specific survival in patients with renal cell carcinoma and tumor thrombus

BACKGROUND

Although different prognostic factors for patients with renal cell carcinoma (RCC) and vena cava tumor thrombus (TT) have been studied, the prognostic value of histologic subtype in these patients remains unclear.

OBJECTIVE

We analyzed the impact of histologic subtype on cancer-specific survival (CSS).

DESIGN, SETTINGS, AND PARTICIPANTS

We retrospectively analyzed the records of 1774 patients with RCC and TT who underwent radical nephrectomy and tumor thrombectomy from 1971 to 2012 at 22 US and European centers.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Multivariable ordered logistic and Cox regression models were used to quantify the impact of tumor histology on CSS.

RESULTS AND LIMITATIONS

Overall 5-yr CSS was 53.4% (confidence interval [CI], 50.5-56.2) in the entire group. TT level (according to the Mayo classification of macroscopic venous invasion in RCC) was I in 38.5% of patients, II in 30.6%, III in 17.3%, and IV in 13.5%. Histologic subtypes were clear cell renal cell carcinoma (cRCC) in 89.9% of patients, papillary renal cell carcinoma (pRCC) in 8.5%, and chromophobe RCC in 1.6%. In univariable analysis, pRCC was associated with a significantly worse CSS (p<0.001) compared with cRCC. In multivariable analysis, the presence of pRCC was independently associated with CSS (hazard ratio: 1.62; CI, 1.01-2.61; p<0.05). Higher TT level, positive lymph node status, distant metastasis, and fat invasion were also independently associated with CSS.

CONCLUSIONS

In our multi-institutional series, we found that patients with pRCC and vena cava TT who underwent radical nephrectomy and tumor thrombectomy had significantly worse cancer-specific outcomes when compared with patients with other histologic subtypes of RCC. We confirmed that higher TT level and fat invasion were independently associated with reduced CSS.

A review of contemporary data on surgically resected renal masses--benign or malignant?

OBJECTIVE

To clearly define the proportions of benign vs malignant histologic findings in resected renal masses through an in-depth review of the contemporary medical data to assist in preoperative risk assessment.

MATERIALS AND METHODS

PubMed and select oncology congresses were searched for publications that identify the histologic classification of resected renal masses in a representative sample from the contemporary data: [search] incidence AND (renal cell carcinoma AND benign); incidence AND (renal tumor AND benign); percentage AND (renal cell carcinoma AND benign); limit 2003-2011.

RESULTS

We identified 26 representative studies meeting the inclusion criteria and incorporating 27,272 patients. The frequency of benign tumors ranged from 7% to 33%, with most studies within a few percentage points of the mean (14.5% ± 5.2%, median 13.9%). Clear cell renal cell carcinoma occurred in 46% to 83% of patients, with a mean of 68.3% (median 61.3; SD = 11.9%). An inverse relationship between tumor size and benign pathologic features was identified in 14 of 19 (74%) studies that examined an association between tumor size and pathologic characteristics. A statistically significant correlation between clear cell renal cell carcinoma and tumor size was identified in 13 of 19 studies (63%). The accuracy of preoperative cross-sectional imaging was low in the 2 studies examining computed tomography (17%).

CONCLUSION

Benign renal tumors represent ∼15% of detected surgically resected renal masses and are more prevalent among small clinical T1a lesions. Noninvasive preoperative differentiation between more and less aggressive renal masses would be an important clinical advance that could allow clinicians greater diagnostic confidence and guide patient management through improved risk stratification.

Temporary targeted renal blood flow interruption using a reverse thermosensitive polymer to facilitate bloodless partial nephrectomy: a swine survival study

What's known on the subject? and What does the study add? Lumagel™ is a reverse thermosensitive polymer (RTP) that has previously been described in the literature as providing temporary vascular occlusion to allow for bloodless partial nephrectomy (PN) while maintaining blood flow to the untargeted portion of the kidney. At body temperature, Lumagel™ has the consistency of a viscous gel but upon cooling rapidly converts to a liquid state and does not reconstitute thereafter. This property has allowed for it to be used in situations requiring temporary vascular occlusion. Previous experience with similar RTPs in coronary arteries proved successful, with no detectable adverse events. We have previously described our technique for temporary vascular occlusion of the main renal artery, as well as segmental and sub-segmental renal branches, to allow for bloodless PN in either an open or minimally invasive approach. These experiments were performed in the acute setting. This study is a two-armed survival trial to assess whether this RTP is as safe as hilar clamping for bloodless PN. Surviving animals showed normal growth after using the RTP, absence of toxicity, no organ dysfunction, and no pathological changes attributable to the RTP. We conclude that Lumagel™ is as safe as conventional PN with hilar clamping, while adding the advantage of uninterrupted perfusion during renal resection.

OBJECTIVE

To examine whether randomly selected regions of the kidney could undergo temporary flow interruption with a reverse thermosensitive polymer (RTP), Lumagel™ (Pluromed, Inc., Woburn, MA, USA), followed by partial nephrectomy (PN), without adding risks beyond those encountered in the same procedure with the use of hilar clamping.

MATERIALS AND METHODS

A two-armed (RTP vs hilar clamp), 6-week swine survival study was performed. Four swine underwent PN using hilar clamps, while six underwent PN with flow interruption using the RTP. The RTP, administered angiographically, was used for intraluminal occlusion of segmental or subsegmental arteries and was compared with main renal artery clamping with hilar clamps. The resection site was randomized for each swine. Laboratory studies were performed preoperatively, and at weeks 1, 3 and 6. Before killing the swine, repeat angiography was performed with emphasis on the site of previous flow interruption. Gross and microscopic examination of kidney, liver, lung, heart, skeletal muscle was later performed, and the vessel that had supported the previous plug was examined.

RESULTS

All animals survived. No abnormal chemistry or haematology results were encountered over the 6 weeks. There were no surgical complications in either group. Using angiography we found 100% patency of vessels that had been occluded with the polymer 6 weeks previously for PN. The only gross or microscopic abnormalities were related to the renal resection and scar formation, and were similar in the two groups.

CONCLUSION

Targeted flow interruption with the RTP added no additional risk to PN while allowing bloodless resection and uninterrupted flow to untargeted renal tissue.

Next-generation point-of-care immunoassay system for rapid and accurate determination of cancer markers in the physician office

e15196

Background: Claros Diagnostics (Woburn, MA) has developed a novel multiplex immunoassay system designed to transition diagnostic tests performed at the centralized laboratory to the point-of-care (POC). The credit card-sized microfluidics disposable analyzes a fingerstick drop of whole blood with laboratory-quality results in 10 minutes, with significant ease-of-use. Total PSA was selected as an initial test to validate that this platform technology can achieve equivalent sensitivity, absence of interferences, etc. as compared to the reference laboratory. Further, the need to clinically validate the use incentives of such a POC system in optimizing the patient-physician encounter, practice efficiency, and overall quality of care were explored. Methods: We completed two consecutive studies measuring PSA in whole blood with the Claros system against the laboratory results in a matching serum sample. The first study entailed 72 patients from two sites and compared fingerstick samples against the laboratory Siemens Centaur serum assay, while the second study compared PSA results from 34 patients’ whole blood against the laboratory Roche E-170 serum assay. All studies were conducted under IRB approved protocols. Results: The PSA values measured in the 72 patients ranged from <0.1 to 8.3 ng/mL. Linear regression yielded a slope of 1.05 and a R2 value of 0.94. Range of PSA values in the second study on 34 patients were <0.1 to 13.5 ng/mL, from which the linear regression analysis yielded a slope of 1.04 and a R2 value of 0.98. In addition, specific data obtained between 0.1 and 1 ng/mL yielded an excellent correlation with a slope of 0.93 and a R2 value of 0.94. Overall (n=106) 7 patients were measured <0.1ng/mL by both assays. Conclusions: Quantitative results obtained with the Claros POC system using a fingerstick of whole blood correlated extremely well with laboratory assays over the clinically relevant range of PSA, including at very low PSA concentrations (essential to detect cancer recurrence post-intervention). Overall ease of use, the ability to use fingerstick blood and short time-to-result converge in improving physician practice efficiency and patient-physician interactions.

Incidence of benign versus malignant renal tumors in selected studies

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Background: Use of cross-sectional imaging has increased the detection rate for small renal tumors; more patients now present with early-stage renal cell carcinoma (RCC) or benign or indolent renal masses. Histopathology after surgical resection is the definitive method for characterizing renal tumors. Stage migration of renal masses creates uncertainty about the percentage of resected masses that will be benign vs malignant. We sought to better define these proportions through a targeted review of the literature.

Methods: PubMed/select congresses were searched to identify the histologic classification of renal masses in a representative sample from the contemporary literature: [search] incidence AND (renal cell carcinoma AND benign); incidence AND (renal tumor AND benign); percentage AND (renal cell carcinoma AND benign); limit: 2003–2011.

Results: Most representative studies included procedures conducted in the mid-1990s to the mid-to-late 2000s. Studies origin was US (n=8), Korea (n=3), China, Japan, Germany, Austria, Australia, and multisite (Israel/France/US; all n=1). Only 8 studies had n≥500 (range, 70–10,404). The proportion of benign masses are shown (see Table); half of the studies reported values between 16% and 17%. The majority found that benign tumors were more likely to be smaller in size (<4 or <7 cm) than malignant tumors. 11 studies reported the RCC subtype (% clear cell range, 46%–83%).

Conclusions: Benign renal tumors occur ~15% of the time and are more prevalent among small masses. Nearly 25% of resected lesions are benign or indolent and may not require surgery. Preoperative discrimination of more aggressive renal masses would be an important clinical advance that could improve clinicians’ diagnostic confidence and guide patient management. Funding: Wilex AG/IBA Molecular.

[Table: see text]

Temporary targeted hemostasis to facilitate bloodless partial nephrectomy

OBJECTIVE

To extend previous robotic-assisted techniques developed in the swine model to studies of laparoscopic and open partial nephrectomy conducted in pigs and calves, designed to encompass vessel diameters similar to those encountered in humans. Lumagel (Pluromed, Woburn, MA), a nontoxic polymer, can be administered intra-arterially under fluoroscopic guidance to obtain a bloodless operative field during partial nephrectomy while maintaining normal circulation to uninvolved renal tissue.

METHODS

A total of 10 animals (7 pigs and 3 calves) underwent flow interruption to the kidney, 2 with cross-clamping of the main renal artery, the remaining with Lumagel. Other than the first pig and calf, all the animals then underwent partial nephrectomy.

RESULTS

Using Lumagel, targeted blood flow interruption was achieved and circulation to the uninvolved renal tissue was maintained. Hemostasis lasted for ≥30 minutes. The surgical resection time averaged 11 minutes (range 10-13) and 23.3 minutes (range 9-40) in the open and laparoscopic groups, respectively. The estimated blood loss was negligible, with the exception of 2 cases, 1 in which an error in angiographic assessment led to an unoccluded vessel near the resection site and a second case in which a guidewire was inadvertently passed through a vessel. The interval to complete flow return, as determined by direct visualization of the kidney and its corresponding angiogram, averaged 7 and 2.5 minutes for Lumagel and arterial clamping, respectively.

CONCLUSION

Lumagel provides reliable and reproducible intraluminal blood flow interruption and flow restoration in both main and segmental renal arteries. By providing blood-free resection, the techniques described could facilitate partial nephrectomy without global renal ischemia.

Abstract 1161: Detection and identification of a miRNA expression profile from cell-free urine: Potential utility in bladder cancer

Introduction/Objective: MicroRNAs are small, non-coding RNAs that have been shown to play an important role in tumorigenesis. There is differential expression of miRNA in cancer progression, and profiling of miRNA is promising for both diagnosis and treatment of malignant tumors. In this study we isolated RNA from cell-free urine in an attempt to characterize miRNA profiles indicating the presence of urothelial carcinoma and its potential use as a non-invasive assay to identify patients with cancer progression.

Methods: Urine was collected from patients diagnosed with bladder cancer and control patients with no history of cancer under an IRB-approved protocol. Urine was centrifuged and total RNA was isolated from the supernatants using the mirVana Paris™ kit. A total of 178 samples were grouped according to grade and stage (healthy controls (35), TaG1 (19), T1G3 (16), ≥T2 (30), carcinoma in situ (CIS; 28) and no evidence of disease following therapy (50). Seven hundred and thirty miRNAs were profiled by qRT-PCR on pooled samples within each group. Validation of selected miRNAs was performed on individual samples using qRT-PCR.

Results: Cell-free RNA was isolated from urine of 35 healthy controls and 143 patients with bladder cancer. Of the 730 miRNAs tested, 236 were detected in at least one of the pooled samples using a Ct cutoff of 35. The number of miRNAs detected in the pooled samples correlated with disease progression where the healthy control group and the ≥T2 group expressed 8 and 228 miRNAs, respectively. qRT-PCR of individual samples revealed a gradual increase of some miRNAs with disease progression. Statistical analysis adjusted for multiple comparisons demonstrated differences between groups based on miRNA expression levels. In addition, a panel of miRNAs was identified which discriminated between cancer and cancer-free patients.

Conclusion: This study demonstrates the successful isolation of miRNAs from cell-free urine. Utilizing non-invasive urine based assays, we identified a miRNA panel that can discriminate between cancer-free patients and patients with urinary carcinoma of the bladder. These findings provide evidence that profiling of miRNAs from cell-free urine holds the promise for the development of valuable clinical tools.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1161. doi:10.1158/1538-7445.AM2011-1161

Prognostic impact of the 2009 UICC/AJCC TNM staging system for renal cell carcinoma with venous extension

BACKGROUND

The prognostic significance of venous involvement and tumour thrombus level in renal cell carcinoma (RCC) remains highly controversial. In 2010, the American Joint Committee on Cancer (AJCC) and the Union International Centre le Cancer (UICC) revised the RCC staging system (7th edition) based on tumour thrombus level, differentiating the T stage of tumours limited to renal-vein-only involvement.

OBJECTIVE

We aimed to evaluate the impact of tumour thrombus extension in a multi-institutional cohort of patients.

DESIGN, SETTING, AND PARTICIPANTS

An international consortium of 11 institutions was established to retrospectively review a combined cohort of 1215 patients undergoing radical nephrectomy and tumour thrombectomy for RCC, including 585 patients with inferior vena cava (IVC) involvement or higher.

MEASUREMENTS

Predictive factors of survival, including histology, tumour thrombus level, nodal status, Fuhrman grade, and tumour size, were analysed.

RESULTS AND LIMITATIONS

A total of 1122 patients with complete data were reviewed. The median follow-up for all patients was 24.7 mo, with a median survival of 33.8 mo. The 5-yr survival was 43.2% (renal vein involvement), 37% (IVC below the diaphragm), and 22% with caval involvement above the diaphragm. On multivariate analysis, tumour size (hazard ratio [HR]: 1.64 [range: 1.03-2.59]; p=0.036), Fuhrman grade (HR: 2.26 [range: 1.65-3.1]; p=0.000), nodal metastasis (HR: 1.32 [range: 1.09-1.67]; p=0.005), and tumour thrombus level (HR: 2.10 [range: 1.53-3.0]; p=0.00) correlated independently with survival.

CONCLUSIONS

Based on analysis of the largest known cohort of patients with RCC along with IVC and atrial thrombus involvement, tumour thrombus level is an independent predictor of survival. Our findings support the changes to the latest AJCC/UICC staging system.

Novel ZEB1 expression in bladder tumorigenesis

What's known on the subject? and What does the study add? Epithelial-mesenchymal transition (EMT) is involved in tumor progression where the underlying cellular changes associated with EMT have been identified in in vitro models and confirmed in a limited number of in vivo studies. ZEB1, which targets E-cadherin repression, is a transcriptional regulator that has been implicated in EMT, and is associated with uterine and colorectal cancers. Regulation of ZEB1 expression has been shown to involve different microRNAs (miRNAs), identifying a potential role for miRNA in EMT. In the present study we have identified novel expression of ZEB1 in bladder tumours and shown a role for ZEB1 in enhanced migration and invasion potential in in vitro assays. Confirmation of ZEB1 expression in bladder tumours was shown in tissue microarrays (TMAs).

OBJECTIVE

To evaluate ZEB1 expression in bladder tumorigenesis and define a possible role for this transcription factor in urothelial carcinomas of the bladder (UCBs).

MATERIALS AND METHODS

Five hundred and fifty-eight samples were assembled in 10 tissue microarrays (TMAs; 263 non-muscle-invasive Ta/T1/Tis, 295 muscle-invasive T2-T4). All tumours were transitional cell carcinomas (TCCs) and processed for immunohistochemistry to assess nuclear ZEB1 expression. Expression levels of ZEB1 were modulated in bladder carcinoma cell lines CUBIII or UM-UC-3 after forced expression or shRNA knockdown, respectively. Protein expression levels were determined using western blot analysis and transfectants were assessed for migration and invasion potential in standard in vitro assays.

RESULTS

Nuclear ZEB1 expression was recorded in 22.8% of non-muscle-invasive UCBs and 21.7% of muscle-invasive UCBs, including 24.1% grade I/II and 21.1% grade III tumours, and absent in normal bladder mucosa. No significant correlation was observed for tumour stage and grade, nodal involvement, vascular invasion, metastasis and overall or cancer-specific survival. The introduction or knockdown of ZEB1 expression in bladder carcinoma cell lines showed enhanced or reduced migration and invasive potential, respectively. Changes in ZEB1 expression were accompanied by altered microRNA (miRNA) expression underlying events linked to epithelial-mesenchymal transition (EMT).

CONCLUSION

The results in the present study showed novel expression of ZEB1 in bladder cancer in the absence of a link to clinical variables of change, including metastasis and survival. However, in vitro assays showed enhanced or reduced migration and invasion after the introduction or reduction of ZEB1, respectively, in transfected bladder cell lines. Modulation in expression of ZEB1 was closely linked to changes in the miR-200 family along with alternative known prognostic indicators of bladder tumour progression.

Identification of tumor and invasion suppressor gene modulators in bladder cancer by different classes of histone deacetylase inhibitors using reverse phase protein arrays

PURPOSE

We assessed the ability of different classes of histone deacetylase inhibitors to target tumor and invasive suppressor genes in a panel of bladder carcinoma cell lines using reverse phase protein arrays.

MATERIALS AND METHODS

Three poorly, moderately and highly invasive cell lines were exposed to histone deacetylase inhibitors, trichostatin A, apicidin, valproic acid (Sigma) and MS-275 (AXXORA) for 0 to 36 hours. Lysates were harvested and arrayed in a 10-fold dilution series in duplicate. Data points were collected and analyzed using a concentration interpolation methodology after normalization.

RESULTS

Protein expression profiles revealed up-regulation of gamma-catenin in highly invasive lines, and alpha-catenin in moderately and highly invasive lines after exposure to all histone deacetylase inhibitors, apicidin and MS-275, respectively. Gelsolin was up-regulated in poorly and moderately invasive lines after exposure to all histone deacetylase inhibitors. Desmoglein was down-regulated in poorly and moderately invasive cell lines by all 4 histone deacetylase inhibitors, in addition to decreased FAK (Transduction Laboratories) expression in moderately and highly invasive lines exposed to valproic acid and MS-275.

CONCLUSIONS

Different histone deacetylase inhibitor classes have the potential to modulate tumor and invasive suppressor gene expression, identifying histone deacetylase inhibitors as potential therapeutic agents for bladder cancer. Reverse phase protein arrays enable high throughput screening of multiple compounds to assess the expression profile of specific protein groups targeted for therapy.

Abstract 3026: miR-203 and miR-205 expression profiles are predictive of high grade non-invasive urothelial carcinoma progression

Introduction: MicroRNA (miRNA) has been shown to play a role in regulating the expression of genes involved in tumor suppression and oncogenesis. High-grade, non-muscle-invasive urothelial carcinoma of the bladder (UCB) harbors a significant risk of progression to muscle invasion. In this study, we sought to identify miRNAs differentially expressed in non-progressive high-grade non-muscle-invasive UCB as compared to pathologically identical lesions that progress to muscle invasion.

Methods: Total RNA was extracted from formalin fixed paraffin-embedded tissue (FFPE) of high-grade non-muscle-invasive (TaG3/T1G3) UCB lesions. Patients were categorized into two groups: non-progressors with at least 3 years follow-up or progressors advancing to ≥T2. Exclusion criteria were previous tumors of the upper tract, prior systemic chemotherapy or previous pelvic irradiation. Total RNA was pooled for microarray analysis from a subset of the non-progressor and progressor groups. Data was analyzed using the LOWESS normalization method. Expression profiles of miRNAs were verified with qRT-PCR on 89 high-grade non-muscle-invasive UCB (68 non-progressors and 21 progressors). Logistic regression analysis was performed to identify miRNAs predictive of tumor progression.

Results: MicroRNA microarray data identified a panel of miRNAs (25) with potential involvement in the progression to invasion of high-grade non-muscle-invasive UCB. 36% of these miRNAs were upregulated and 64% were downregulated in the progressor samples. To validate differential expression of these miRNAs, qRT-PCR was performed on the 89 FFPE tissue samples. Logistic regression analysis of qRT-PCR data revealed decreased expression of miR-203 and miR-205 as predictive of progression (p = 0.031 and p = 0.045, respectively). Subsequent qRT-PCR with miR-203 and miR-205 on 31 muscle-invasive tumor samples (≥T2) showed expression profiles that were similar to those of the non-invasive progressors.

Conclusions: In this study, we have shown that miR-203 and miR-205 can identify patients with non-muscle- invasive UCB at high risk to progress to muscle-invasive disease. Our findings also suggest that such tumors have a biomolecular profile similar to muscle-invasive lesions. Further validation studies are underway to investigate additional miRNAs and determine the mechanism by which these miRNAs promote tumor invasion and progression. These results provide an important tool that can be used to prognosticate the clinical behavior of a very challenging subset of tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3026.

Endovascular temporary vessel occlusion with a reverse-thermosensitive polymer for bloodless minimally invasive renal surgery

PURPOSE

To demonstrate the feasibility of reversible vessel embolization with angiographic guidance for delivery of a rapid reverse-thermosensitive polymer to provide hemostasis as an aid for minimally invasive renal surgery in a porcine model.

MATERIALS AND METHODS

After isolation of the left kidney of seven anesthetized pigs (50-70 kg) with a surgical robot, a renal angiogram of both kidneys was obtained. A 5-F angiographic catheter was used to selectively embolize a lower-pole segmental artery of the right and left kidney with a thermosensitive polymer (LeGoo-XL). Distal and proximal embolization of the target vessel was compared. Degree and duration of hemostasis and reversibility was determined. After complete hemostasis was obtained angiographically, a partial robotic lower-pole nephrectomy was performed on the left kidney only.

RESULTS

Only proximal embolization provided controllable hemostasis. A 20% polymer concentration in a buffer solution of 40% saline solution and 40% iodine contrast medium by weight injected at room temperature resulted in a reproducible embolus for more than 30 minutes, the time needed to perform a partial nephrectomy. The radiographic appearance of the embolus was used to determine the total amount of polymer needed. Cold saline solution completely dissolved any residual polymer at the end of surgery.

CONCLUSIONS

Proximal arterial occlusion with a thermosensitive polymer can be rapidly reversed with selective intraarterial infusion of chilled saline solution. Preceding nephron-sparing surgery with transcatheter embolization of the relevant branch of the renal artery with the polymer can facilitate the procedure and ought to be investigated further.

A MicroRNA expression profile defining the invasive bladder tumor phenotype

OBJECTIVE

The purpose of this study was to identify microRNA (miRNA) involved in the transition between the noninvasive and invasive urothelial carcinoma of the bladder (UCB) phenotype.

METHODS

Differential expression of miRNA was identified in a microarray format between noninvasive and invasive UCB cell lines and confirmed using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) within this cell panel. Normalization of qRT-PCR with miR-222 was established from the microarray data and validated within a panel of 57 UCB tumors (26 noninvasive lesions (Ta/G1) and 31 invasive lesions (T2-T4). Pre-miR constructs were transfected into appropriate UCB cell lines to establish a change in invasive potential.

RESULTS

Differential expression of miRNAs was identified from microarray analysis and included reduced expression associated with miR-30b, miR-31, miR-141, miR-200a, miR-200b, miR-200c, miR-205, miR-21 in invasive lesions and elevated miR-99a in noninvasive UCB lesions. Reduced invasion potential was recorded in UM-UC-3, following pre-miR transfection, in all UCB cell lines with the exception of UM-UC-3/miR-30b transfectants. Our results identify a panel of miRNA modulated and expressed in invasive UCB tumors and demonstrates a role for them in the invasive phenotype.

CONCLUSIONS

The diagnostic test, based on the three most discriminatory miRNAs in our panel (miR-200c, miR-141, and miR-30b), showed a sensitivity of 100% and a specificity of 96.2%. Such a panel of miRNAs has the potential to identify invasive bladder tumors misclassified in pathologic assessment of bladder biopsy specimens.

A novel approach to using matrix metalloproteinases for bladder cancer

PURPOSE

Given the steadily growing cancer survivor population, increasing pressure has been placed on more effective clinical approaches and biomarker assays to manage care. For bladder cancer despite the high probability of recurrence the number of patients with recurrent disease is significantly lower than the number that remains cancer free at any monitoring interval. We developed a noninvasive urine assay using a novel approach to identify patients without recurrent cancer with extremely high confidence.

MATERIALS AND METHODS

Previous studies show that matrix metalloproteinases are increased in the urine of patients with cancer compared to that in disease-free individuals. To determine the clinical usefulness of these markers as monitors for bladder cancer recurrence we measured and compared metalloproteinase-2, metalloproteinase-9 and metalloproteinase-9/neutrophil gelatinase-associated lipocalin by enzyme-linked immunosorbent assay and zymography in a set of 530 samples, including 84 samples from patients with bladder cancer.

RESULTS

Initial studies using urine metalloproteinase to discriminate disease-free patients from those with bladder cancer resulted in 80% sensitivity (67 of 84) and 71% specificity (318 of 446) for metalloproteinase-9. By applying our novel Clinical Intervention Determining Diagnostic() clinical approach to metalloproteinase-9 we correctly identified 42% of cases that were cystoscopy negative with 98% negative predictive value.

CONCLUSIONS

A noninvasive urine diagnostic assay that uses metalloproteinases with the Clinical Intervention Determining Diagnostic could lead to more efficient treatment in bladder cancer survivors by decreasing the number of negative cystoscopies (42%), allowing physicians to more selectively monitor those at high risk.

A microRNA expression ratio defining the invasive phenotype in bladder tumors

OBJECTIVE

The goal of this study was to identify a microRNA (miRNA) signature in bladder cancer capable of differentiating superficial from invasive disease.

METHODS

Expression profiling of 343 miRNAs was performed in a microarray format using noninvasive and invasive bladder carcinoma cell lines with differential expression confirmed using a single molecule detection platform assay. miR-21 and miR-205 expression levels were determined in 53 bladder tumors (28 superficial and 25 invasive). Sensitivity, specificity, and a ROC curve were calculated to determine the discriminatory power of the miRNA ratio to predict invasion. Knockdown and forced expression of miRNAs was performed to evaluate their role in invasion.

RESULTS

Expression profiling of 343 miRNAs, using noninvasive and invasive bladder cell lines, revealed significant differential expression of 9 miRNAs. Cell lines characterized as invasive showed a miR-21:miR-205 ratio at least 10-fold higher than the quantitative ratio obtained from non-invasive cell lines. The same expression ratio was determined in 53 bladder tumors. From these results, we recorded a sensitivity and specificity of 100% and 78%, respectively, using a cutoff of 1.79 to predict an invasive lesion. The area under the receiver operator characteristic curve was 0.89. Using in vitro invasion assays, we have demonstrated a role for miR-21 in establishing the invasive phenotype of bladder carcinoma cells.

CONCLUSION

In this study, we identified a miR-21:miR-205 expression ratio that has the ability to distinguish between invasive and noninvasive bladder tumors with high sensitivity and specificity, with the potential to identify superficial lesions at high risk to progress.