Defining molecular determinants of sensitivity to EGFR inhibition in urothelial carinoma

268

Background: Activation of EGFR in cancer patients has been shown to correlate with tumor proliferation, angiogenesis, and metastasis. EGFR inhibition has been shown to be clinically beneficial in several solid tumors and appears to be a tractable therapeutic target. EGFR is over-expressed in bladder cancer and a phase II trial of neoadjuvant erlotinib in patients with muscle invasive bladder cancer suggests possible clinical activity. We therefore hypothesized that we could define molecular correlates to predict response to EGFR inhibition.

Methods: Correlative tumor samples derived from a phase II trial of neoadjuvant erlotinib in muscle invasive urothelial carcinoma of the bladder were analyzed to define molecular determinants of response to EGFR inhibition. The effect of silencing a candidate molecular predictor of resistance to EGFR inhibition, HRAS, was assessed by changes in the IC50 of T24 cells (harbor mutant HRAS) expressing short hairpin RNAs to HRAS or a control shRNA.

Results: Analysis of the gene expression profiles of TURB-T (pretreatment) samples show that tumors from non-pT0 patients had significantly elevated levels of HRAS relative to tumors from pT0 patients. Furthermore, knock-down of HRAS in T24 cells enhanced the sensitivity of these cells to erlotinib.

Conclusions: Elevated HRAS expression is correlated with a lack of response to erlotinib in vivo and silencing of HRAS in T24 cells results in enhanced sensitivity to erlotinib in vitro. Further molecular analyses are ongoing.

No significant financial relationships to disclose.

Risk-specific intensity of surveillance practices in non-muscle-invasive bladder cancer: Results from the BCAN/SUO/AUA/LUGPA electronic survey

251

Background: The ideal surveillance regimen for patients with non-muscle-invasive bladder cancer (NMIBC) is uncertain. Given different grade- and stage-specific risks of recurrence and progression, there is some question whether it might be acceptable to pursue less intensive surveillance practices for patients with lower risk disease, and there is a paucity of data on current patterns of care in this area of practice.

Methods: An electronic survey was developed by the Bladder Cancer Advocacy Network (BCAN) to elicit self-reported practices of cystoscopy, cytology, and radiographic testing in the setting of surveillance for patients with a history of NMIBC. The survey was circulated to urologists via the AUA, SUO and LUGPA distribution lists. 512 respondents completed the survey.

Results: Among respondents, 66% report performing cystoscopy every 3 months on all patients for at least the first two years following diagnosis of NMIBC. The remaining 33% report performing surveillance cystoscopy less frequently, 95% of whom report doing so in the setting of low grade pathology. Similarly, 51% report using cytology with every cystoscopy, 23% do so for all high grade cases, and 30% report not using cytology with every cystoscopy. In the absence of recurrence for patients with an initial high grade diagnosis, upper tract reimaging is performed annually in 48%, biannually in 37% and never in 3%. The corresponding figures for patients with an index diagnosis of low grade disease are 14%, 37% and 28%, respectively. In the event of a recurrence in the bladder, 80% of respondents report reimaging the upper tracts for patients with high grade disease, versus 45% in the event of a low grade recurrence.

Conclusions: A substantial number of urologists responding to a survey report using relatively less intensive surveillance practices in patients with lower risk NMIBC. These results suggest a lack of consensus on the ideal intensity of evaluation in this setting, and provide a basis for prospective studies to validate the safest and most cost-effective strategies for surveillance.

No significant financial relationships to disclose.

Patterns of utilization of urine-based markers in non-muscle-invasive bladder cancer: Results from the BCAN/SUO/AUA/LUGPA electronic survey

261

Background: In addition to cytologic evaluation, there are currently four urine-based tests approved by the FDA for bladder cancer detection. At this point, the Guidelines panels from the AUA and EAU do not make specific recommendations about the ideal role of these tests. Furthermore, there is a paucity of data on current patterns of care in this area of practice.

Methods: An electronic survey was developed by the Bladder Cancer Advocacy Network (BCAN) to elicit self-reported practices of the use of cytology and urine-based markers in the settings of general use, surveillance, and assessment of response after intravesical therapy for patients with NMIBC. The survey was circulated to urologists via the AUA, SUO and LUGPA distribution lists. 512 respondents completed the survey.

Results: Among all respondents, 93% report sending cytology routinely (25% via barbotage) in general use. In contrast, 37% report using NMP22 in this setting, 54% report using FISH, and 32% (45% of SUO respondents vs. 31% of AUA respondents, p=0.04) responded that there is “no role for urine-based markers in this setting.” Similar proportions were reported in the specific settings of routine surveillance and post-BCG assessment. When presented with the vignette of a positive marker test and negative cytology and cystoscopy, 36% chose to proceed to the OR for biopsy, 37% chose to repeat cystoscopy and cytology in 3 months, 21% chose “no role for markers in this setting” and 13% chose “other.”

Conclusions: In the absence of more specific guidance, the results of this survey suggest considerable variation in the use and interpretation of urine-based markers in NMIBC. FISH is the marker reported to be used most commonly in multiple settings, however 31-45% of respondents report “no role” for any of the tests in their practice. Greater than one out of three respondents reported taking patients for biopsy under anesthesia in the setting of an isolated positive marker. These preliminary data underscore the need for prospective studies to validate the optimal role of urine-based markers in the setting of NMIBC.

No significant financial relationships to disclose.

Recurrence and survival following preoperative sorafenib for advanced renal cell carcinoma

384

Background: The impact of neoadjuvant or preoperative therapy in the setting of advanced renal cell carcinoma on recurrence-free or survival outcomes is not known.

Methods: 28 patients with renal cell carcinoma were treated with preoperative sorafenib in a prospective pilot study (LCCC 0603). Patient files were reviewed a median of 885 days (2.42 years) following nephrectomy. Records were evaluated for 13 patients with nonmetastatic disease for development of recurrence, and for 15 patients with stage IV disease for survival.

Results: For the nonmetastatic patients, only 2 patients had developed recurrent disease, one underwent metastectomy and remains in surveillance and the other is on second line systemic targeted therapy. A median recurrence-free survival has not been met after a median 2.5 years. For stage IV disease patients at a median follow up of 2.3 years, a median survival has also not been reached. Four patients are deceased, one patient is lost to follow up, and 10 remain alive. Treatments for metastatic disease included continued sorafenib, high dose interleukin-2, sunitinib, pazopanib, temsirolimus, and everolimus. Some stage IV patients have also enjoyed prolonged treatment-free intervals ranging from six months to over two years, with biopsy confirmed, but indolent disease.

Conclusions: Although these data are descriptive, these observations are suggestive that preoperative therapy with sorafenib is unlikely to accelerate the growth of grossly metastatic or micrometastatic disease. Further studies are needed to determine whether preoperative therapy is valuable in improving recurrence-free or overall survival endpoints.

[Table: see text]

Reported patterns of utilization of intravesical therapy in non-muscle-invasive bladder cancer: Results from the BCAN/SUO/AUA/LUGPA electronic survey

267

Background: Guidelines recommend intravesical chemotherapy and immunotherapy in the management of non-muscle-invasive bladder cancer (NMIBC) to reduce the risks of recurrence and potentially progression. Nevertheless, recent claims-based analyses have suggested exceedingly low rates of utilization of some of these therapies in practice. In general, there is a paucity of data to inform our understanding of current patterns of care.

Methods: An electronic survey was developed by the Bladder Cancer Advocacy Network (BCAN) to elicit self-reported practices of utilization of intravesical chemo- and immuno-therapy for patients with NMIBC. The survey was circulated to urologists via the AUA, SUO and LUGPA distribution lists. 512 respondents completed the survey.

Results: Overall, 63% of respondents reported routine administration of perioperative mitomycin-c (MMC) after TURBT [80% of SUO respondents vs. 55% of AUA/LUGPA respondents (p<0.001)]. Whereas 5% of respondents reported routine induction therapy with all new low-grade (LG) diagnoses, 99% reported routinely doing so in new high-grade (HG) cases; most commonly with single- agent BCG (94%; vs. 9% BCG/IFN and 5% MMC). Reported induction therapy was higher in the setting of high-volume (77%) or frequently recurrent LG (44%) disease. 89% reported routinely using maintenance therapy for HG, vs. 29% for LG. Reduced strength BCG was most commonly endorsed only in the settings of poor tolerance of full strength (84%) or maintenance (11%), with only 3% endorsing routine use. Routine post-BCG biopsy, even with normal cystoscopy, was endorsed by 28% of respondents, and 64% of respondents used urine-based markers to assess response to intravesical therapy.

Conclusions: Urologists report grade-specific patterns of utilization of intravesical therapy for NMIBC, at rates higher than suggested in some claims-based analyses. Variation exists in post-treatment followup practices. Further study is needed to rectify these self-reported patterns of care with results from claims-based analyses.

No significant financial relationships to disclose.

Oncologic outcomes for node-positive patients undergoing robotic radical cystectomy

290

Background: Previous studies have shown robot assisted radical cystectomy (RARC) to have equivalent perioperative outcomes to open radical cystectomy. There are few reports that have examined the oncologic results of RARC specifically with respect to node-positive patients. We report the outcomes of node-positive patients who have undergone RARC with medium-term (at least 1 year) follow-up.

Methods: A total of 275 patients underwent RARC at two institutions for invasive bladder cancer between 2005-present. We examined the 50 patients with node-positive disease that had a minimum of one year follow-up. Oncologic outcomes, recurrence free survival (RFS), and disease specific survival (DSS) were analyzed and compared to the open literature.

Results: Mean clinical follow up in this case series was 29 months (range 12–64 months). The mean number of lymph nodes removed was 18 (range 5–35), and mean number of positive LNs was 3.1 (range 1–12). Overall rate of LN positivity was 26%. Mean LN density was 18%. Seventeen (34%) patients had ≤ pT2 disease and 33 (66%) pT3/T4 disease. At this follow-up, 29 patients have recurred, 21 patients died of disease, giving a RFS and DSS of 42% and 58%, respectively. Mean (median) time to recurrence was 10.2 months (9 months). A total of 60% of patients received peri-operative chemotherapy in this cohort. These findings are consistent with prior reports of such oncologic outcomes in node-positive patients in open series.

Conclusions: The oncologic follow-up of patients undergoing RARC with LN positive disease appears to have acceptable outcomes during medium term (mean 29 months) follow-up. As our follow-up increases, we expect to continue to accurately define the long-term clinical suitability and oncologic success of this procedure in this high-risk population.

No significant financial relationships to disclose.

Robotic radical cystectomy: Medium-term oncologic follow-up

288

Background: We report our experience with robot assisted radical cystectomy (RARC) with regard to medium-term (at least 2 year) oncologic outcomes.

Methods: A total of 275 patients have undergone RARC and urinary diversion at two institutions for invasive bladder cancer between 2005-present. We performed a retrospective analysis of the 139 patients who underwent RARC with a minimum of 2 years follow-up. Medium term oncologic outcomes including recurrence rates, time to recurrence, recurrence free survival (RFS), disease specific survival (DSS) were analyzed. Follow-up was measured from time of surgery to time of most recent clinical follow-up.

Results: This cohort of patients consisted of 108 men (78%) and 31 women (22%) at a mean age of 67.3 years (range 45-86 years). Sixty-one (44%) patients had ≤ pT2 disease, 38 (27%) pT3/T4 disease, and 40 (29%) N+ disease. The mean number of lymph nodes removed was 18 (range 3-41). The average clinical follow up in this case series was nearly 3 years with a mean of 35.9 months (range 24-64 months). At this follow-up, 39 patients have recurred, 27 patients died of disease, and 5 patients died of other causes giving an overall RFS, DSS, and OS rates of 80%, 71%, and 68%, respectively. The mean (median) time to recurrence was 12.3 months (10 months). These findings are consistent with prior reports of the oncologic outcomes for open radical cystectomy.

Conclusions: The oncologic follow-up of patients undergoing RARC appears to be favorable with acceptable outcomes in the medium-term (mean – 3 years). As our follow-up increases, we should expect to truly define the long-term clinical appropriateness and oncologic success of this procedure.

No significant financial relationships to disclose.

Ror2, a developmentally regulated kinase, promotes tumor growth potential in renal cell carcinoma

Inappropriate kinase expression and subsequent promiscuous activity defines the transformation of many solid tumors including renal cell carcinoma (RCC). Thus, the expression of novel tumor-associated kinases has the potential to dramatically shape tumor cell behavior. Further, identifying tumor-associated kinases can lend insight into patterns of tumor growth and characteristics. Here, we report the identification of the RTK-like orphan receptor 2 (Ror2), a new tumor-associated kinase in RCC cell lines and primary tumors. Ror2 is an orphan receptor tyrosine kinase with physiological expression normally seen in the embryonic kidney. However, in RCC, Ror2 expression correlated with expression of genes involved at the extracellular matrix, including Twist and matrix metalloprotease-2 (MMP2). Expression of MMP2 in RCC cells was suppressed by Ror2 knockdown, placing Ror2 as a mediator of MMP2 regulation in RCC and a potential regulator of extracellular matrix remodeling. The suppression of Ror2 not only inhibited cell migration, but also inhibited anchorage-independent growth in soft agar and growth in an orthotopic xenograft model. These findings suggest a novel pathway of tumor-promoting activity by Ror2 within a subset of renal carcinomas, with significant implications for unraveling the tumorigenesis of RCC.

Brefeldin A induces p53-independent apoptosis in primary cultures of human prostatic cancer cells

PURPOSE

The objective of this study was to investigate growth-inhibitory and apoptotic activity of the experimental antitumor drug, brefeldin A (BFA), on primary cultures of human epithelial cells derived from prostatic adenocarcinomas.

MATERIALS AND METHODS

Clonal assays were performed to evaluate the effects of BFA on growth of prostatic cancer cell strains. Loss of cell viability in response to BFA was assessed by trypan blue exclusion. Induction of apoptosis by BFA was evaluated by morphologic criteria, electrophoretic assay of DNA fragmentation, and a cell death ELISA. Immunoblots were used to monitor p53 and pRB expression in response to BFA.

RESULTS

BFA was growth-inhibitory at a half-maximal concentration of 5 ng./ml. (18 nM). Morphological manifestations of apoptosis were evident by 24 hours of treatment. Cell viability declined and the cell death ELISA indicated an 18-fold increase in apoptosis in BFA-treated versus untreated cells at 48 hours. DNA fragmentation was also seen at 48 hours. Levels of p53 were not altered by BFA, but pRB was maintained in a hypophosphorylated state by BFA treatment.

CONCLUSIONS

BFA is a potent inducer of apoptosis in prostatic cancer cells via a p53-independent mechanism. Cells derived from low-grade as well as high-grade cancers responded similarly to BFA. Since p53-mediated pathways of apoptosis may frequently be abrogated in prostatic cancer cells, agents such as BFA that induce p53-independent cell death may be promising candidates for chemotherapeutic agents.

Intrahospital transport of critically ill pediatric patients

OBJECTIVES

To determine the frequency of adverse events during intrahospital transport; to determine the requirement of therapeutic interventions during transport; to test the hypothesis that adverse events that occur during intrahospital transport are due to the transport process itself; and to determine the factors that predict the occurrence of adverse events and the requirement of major therapeutic interventions during transport.

DESIGN

A two-phase study in which data were prospectively collected. In phase I, we examined the occurrence rate of adverse events, the requirement for therapeutic interventions, and the factors that predicted adverse events and the requirement of therapeutic interventions. In phase II, we tested the hypothesis that adverse events during transport were due to the transport process itself.

SETTING

A 250-bed university children's hospital with a 50-bed intensive care unit (ICU).

PATIENTS

Phase I of the study consisted of one hundred and eighty intrahospital transports in 139 patients. These transports included patients who were transferred: a) to the ICU from the operating room, emergency department, or the general ward; b) from the ICU to the operating room; and c) from the ICU for diagnostic or therapeutic procedures. Phase II of the study consisted of 89 transports in 85 patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Vital signs and oxygen saturation were measured before and during transport. In phase I, there were no adverse events in 23.9% of transports. There was a significant change in at least one physiologic variable in 71.7% of transports, and at least one equipment-related mishap in 10% of transports. At least one major intervention was performed in 13.9% of transports in response to physiologic deterioration or an equipment-related mishap. There were no arrests or deaths during transport. The requirement for a major procedure was 34.4% in mechanically ventilated patients vs. 9.5% in nonventilated patients. Logistic regression analysis showed that both pretransport Therapeutic Intervention Scoring System and the duration of transport were significantly associated with the requirement of a major intervention and physiologic deterioration, while only the duration of transport was associated with an equipment-related event. The age of the patient and the number of escorts accompanying the transport did not affect the frequency of adverse events. Before transport in phase II study patients, no patient became hypothermic, the changes in physiologic variables were always < 20%, and there was no change > or = 5% in oxygen saturation. Hypothermia occurred in 11.2% of transports. A > or = 20% change in heart rate (15.7%), blood pressure (21.3%), and respiratory rate (23.6%) was seen only during transport. A > 5% change in oxygen saturation (5.6%) was seen only during transport.

CONCLUSIONS

Serious physiologic deterioration occurs during intrahospital transport of critically ill children. Severity of illness and the duration of transport are associated with the occurrence of adverse events during transport. The team composition and equipment required on transport must be commensurate with the pretransport severity of illness and the anticipated duration of transport.