Opioid Use after Nephrectomy for Kidney Cancer in Ontario: A Population-Based Study

OBJECTIVE

To compare the odds of early and prolonged post-operative opioid use in patients undergoing minimally invasive surgery (MIS) versus open surgery for nephrectomy.

METHODS

For opioid-naïve patients in Ontario who underwent nephrectomy for kidney cancer (1994-2017, n=7900), post-discharge opioid use was determined by prescriptions in the Ontario Drug Benefit database (age ≥65 years) and the Narcotics Monitoring System (all patients from 2012). Early opioid use was defined as ≥ 1 prescription 1-90 days after surgery. Two separate definitions of prolonged opioid use were examined: (1) prescription(s) for ≥ 60 days during post-operative days 90-365; (2) ≥ 1 prescriptions between both of: 1-90 days AND 91-180 days after surgery. Predictors of opioid use were assessed using multivariable generalized estimating equation logistic regression, accounting for surgeon clustering.

RESULTS

Overall, 67.4% of patients received early opioid prescriptions; however, prolonged use was low, ranging from 1.6 to 4.4% of patients depending on the definition. In multivariable analysis, open nephrectomy was associated with higher odds of early opioid use compared to MIS nephrectomy (Odds Ratio [OR] 1.36, 95% Confidence Interval [CI] 1.19-1.55). Surgery type was not significantly associated with prolonged opioid use for either definition (OR 1.22, CI 0.79 1.89 and OR 1.06, CI 0.83, 1.35).

CONCLUSIONS

In this population-level study of patients undergoing nephrectomy for kidney cancer, patients who received open surgery were at increased odds of receiving early post-operative opioids compared to MIS. Prolonged opioid use was low overall and was not significantly with associated with type of surgery.

Study evaluating metastatic castrate resistant prostate cancer (mCRPC) treatment using 177Lu-PNT2002 PSMA therapy after second-line hormonal treatment (SPLASH)

TPS5087

Background: Treatment options with minimal toxicity and novel mechanisms of action are urgently needed to improve clinical outcomes from mCRPC. Prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) represents a new treatment for patients with PSMA-avid mCRPC. 177Lu-PNT2002 (also known as [Lu-177]-PSMA-I&T) is a PSMA-targeting agent and studies have shown demonstrable promising initial data. This trial seeks to prospectively evaluate the efficacy of 177Lu-PNT2002 for men with progressive mCRPC after androgen receptor axis-targeted (ARAT) therapy. Methods: This is a multi-center, open-label, phase III study. All patients must be at least 18 years of age, have documented progressive mCRPC at time of screening, high PSMA expression by PSMA PET/CT per blinded independent central review (BICR), chemotherapy naïve for CRPC and unfit or unwilling to receive chemotherapy. The study will commence with a 25-patient dosimetry lead-in. In the dosimetry phase, patients will receive up to four cycles of 177Lu-PNT2002 at 6.8 GBq every 8 weeks. In the randomization phase, approximately 390 patients will be randomized in a 2:1 ratio to receive 177Lu-PNT2002 (Arm A) versus enzalutamide or abiraterone (with prednisone or dexamethasone) (Arm B). Patients randomized to Arm B have an option to crossover to 177Lu-PNT2002 treatment after BICR-assessed radiologic progression. The primary endpoint is Radiological progression-free survival (rPFS) assessed by BICR using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 (soft tissue) and Prostate Cancer Working Group 3 (PCWG3) (bone) criteria. Key secondary endpoints include objective response rate, duration of response, PSA response, and overall survival. The study is powered at 90% to test the alternative hypothesis of a hazard ratio (HR) ≤ 0.66 at an α of 0.025. ClinicalTrials.gov identifier: NCT04647526. Clinical trial information: NCT04647526.

Time trends of drug specific adverse events among patients on androgen receptor antagonists: Implications for remote monitoring

40

Background: In light of the global pandemic, reducing patient exposure via remote monitoring is desirable. Currently, advanced prostate cancer patients prescribed Abiraterone or Enzalutamide are scheduled for an in-person appointment monthly, to screen for adverse events (AEs). We set out to determine time trends of drug specific AEs in order to determine whether reducing in-person visits for patients taking either Abiraterone or Enzalutamide is feasible. Methods: This chart review was conducted on 667 unique advanced prostate cancer patients, being either metastatic hormone sensitive or castration resistant and utilizing Abiraterone or Enzalutamide. Patients who switched courses of treatment and received both drugs were included twice in the data, resulting in 828 “subjects” overall. Data were collected via accessing electronic patient records, to determine the first sign of an AE related to either Abiraterone or Enzalutamide. These AEs include; hypertension, elevated liver enzymes (bilirubin, AST, ALT) or hypokalemia. Survival analysis was used to determine the time to adverse event. All grade AEs are included in this analysis. Results: In this study, 425 and 403 patients received Enzalutamide and Abiraterone, respectively. In total, 36.3% of those who took Enzalutamide experienced an AE, compared to 43.4% of patients on Abiraterone. For patients utilizing Abiraterone, cumulative incidence of AEs at 3,6,9 and 12 months were: 65.0%, 81.2%, 90.9% and 93.9%, respectively. Among Enzalutamide users, cumulative incidence of AEs at 3,6,9 and 12 months were: 46.8%, 67.5%, 81.2% and 88.3%, respectively. The primary first AEs associated with Enzalutamide consumption were hypertension and liver dysfunction (77.48% and 22.52%). In the Abiraterone group, the first associated AEs were liver dysfunction (48.78%), hypertension (46.34%), and hypokalemia (4.88%). Conclusions: These data suggest that the likelihood of attaining AEs associated with Abiraterone or Enzalutamide utilization decreases over time and tend to occur within the first 6 months of therapy. Furthermore, the vast majority of these AEs can be remotely monitored via outside laboratories and remote blood pressure monitoring. In light of the COVID-19 crisis, remote monitoring after 6 months of taking Abiraterone or Enzalutamide would appear appropriate. Efforts to further safely reduce in person visits should be explored.

The deleterious association between proton pump inhibitors and prostate cancer specific death

309

Background: Proton pump inhibitors (PPIs) are a commonly prescribed class of medications. Although in-vitro and in-vivo data have shown PPIs to have anti-tumor effects, more recent studies suggest an increased cancer risk in several solid organs. Pantoprazole, a commonly prescribed PPI, has been shown to harbor a protective effect in human prostate cancer (PCa) cells. We aimed to investigate the effect of pantoprazole and other PPIs on PCa-specific death and additional PCa outcomes. Methods: In this retrospective, population-based cohort study, data were incorporated from the Institute for Clinical and Evaluative Sciences to identify all men aged 66 and above with a history of a single negative prostate biopsy between 1994 and 2016. We used multivariable Cox regression models with time-dependent covariates, to assess the effect of PPIs on PCa diagnosis, androgen deprivation therapy (ADT) use, and PCa-specific death. All models included other medications with a putative effect on PCa. All models were adjusted for age, rurality, comorbidity, and year of patient study inclusion. Results: Overall, 21,512 men were included, with a mean follow-up time of 8.06 years (SD 5.44 years). A total of 10,999 patients (51.1%) used a PPI. A total of 5,187 patients (24.1%) were diagnosed with PCa, 2,043 patients (9.5%) were treated with ADT, and 805 patients (3.7%) died from PCa. Pantoprazole was associated with a 3.0% (95% CI 0.3%-6,0%) increased rate of being treated with ADT for every six months of cumulative use, while any use of all other PPIs was associated with a 39.0% (95% CI 18.0%-64.0%) increased PCa-specific mortality. No significant association was found with PCa diagnosis. Conclusions: Upon validation of the potentially negative association of PPIs with PCa outcomes, the expansive use of PPIs may need to be reassessed, especially in PCa patients.

Analysis of small non-coding RNAs in urinary exosomes to classify prostate cancer into low-grade (GG1) and higher-grade (GG2-5)

277

Background: To develop a new predictive test for prostate cancer, based on the interrogation of small non-coding RNAs (sncRNA) isolated from urinary exosomes. We report the development and performance of the miR Sentinel PCa Test, that distinguishes patients with prostate cancer from those with no evidence of prostate cancer (NEPC) and the miR Sentinel CS Test, that distinguishes low grade from higher grade disease. Methods: Affymetrix miR 4.0 arrays were used to identify informative sncRNAs isolated from urinary exosomes. sncRNA from 233 subjects undergoing a prostate biopsy [89 men with benign biopsies, 88 with grade group 1 (GG1) cancer and 56 patients with grade group 2-5 (GG2-5)] were interrogated on these arrays. A custom OpenArray platform was designed to interrogate the 280 most informative sncRNAs, identified using a data-driven selection algorithm. The platform was designed to categorize patients as either no cancer or cancer using the miR Sentinel PCa Test, and subclassify the patients with cancer into GG1 or GG2-5 cancer using the miR Sentinel CS Test. The performance of the miR Sentinel PCa and CS Tests was validated in an independent cohort. Results: In 233 men, theSentinel PCa Test correctly classified 89/89 subjects with no cancer and 144/144 with cancer. The Sentinel CS Test correctly identified 55/56 patients with GG2-5 and 87/88 patients with GG1. Sensitivity was 98%, Specificity 98%, NPV 98% and PPV 93%. For validation, a prospective observational study of 329 subjects (NEPC = 139; GG1= 88; GG2-5 = 102) with elevated PSA correctly classified 134/139 as no cancer [Sensitivity 98% (195/199); Specificity 96% (134/139), PPV 98% and NPV 97%]. The Sentinel CS Test classified 87/88 as GG1 and 102/102 as GG2-5 [Sensitivity 100% (102/102), Specificity 99% (87/88), PPV 99%, and NPV=100%]. Conclusions: Initial evaluation of the miR Sentinel PCa and CS Tests demonstrated the high precision of these tests to detect prostate cancer and distinguish high grade (GG2-5) disease. Further validation is ongoing.[Table: see text]

The effect of docetaxel, enzalutamide, abiraterone, and radium-223 on cognitive function in older men with metastatic castrate-resistant prostate cancer (mCRPC)

73

Background: Older adults are at greater risk of cognitive decline with various oncologic therapies. Emerging data suggest cognitive effects of various therapies for mCRPC but study populations are highly selected and published data are limited and focus mostly on self-reported cognitive function. We evaluated the effects of treatment with docetaxel chemotherapy (CHEMO), abiraterone (ABI), enzalutamide (ENZA), and radium 223 (Ra223) on cognitive function in older men with mCRPC. Methods: Men age 65+ with mCRPC starting any of the 4 treatments for mCRPC were enrolled in this multicenter prospective cohort study. Three short yet reliable and sensitive measures in older adults were administered at baseline and final visit (6 months with CHEMO and Ra223, mean 14-16 months with ENZA and ABI) using the Montreal Cognitive Assessment (MoCA), Trails A, and Trails B to assess global cognition, attention, and executive function, respectively. Absolute changes in cognitive scores over time were analyzed using multivariable linear regression, and the percentage of individuals with a decline of 1.5 SD in each domain were calculated. Higher scores on MoCA are better but worse for Trails A/B. Results: A total of 51, 26, 49, and 21 men starting CHEMO, ABI, ENZA, and Ra223 with complete data were included. Mean age, education, and baseline cognition were similar between groups (Table). Most patients demonstrated stable cognition or slight reductions. Executive function was the most sensitive of the 3 cognitive domains, and declined by at least 1.5 SD in about one-fifth of each cohort. Although ABI had numerically smaller declines than ENZA, differences were generally small and clinically unimportant. Conclusions: Most older men do not experience significant cognitive decline while on treatment for mCRPC regardless of treatment used.[Table: see text]

Prognostic factors that affect survival outcomes in men with metastatic castration-resistant prostate cancer (mCRPC) treated with radium-223

225

Background: Radium-223 (Ra-223) improved overall survival (OS) in men with mCRPC with predominantly bone metastases. We analyzed their survival outcomes to identify factors associated with prognosis for men treated with Ra-223. Methods: This was a retrospective study of men with mCRPC at Princess Margaret Cancer Centre treated with Ra-223. Demographics, disease characteristics, number of bone metastasis [ < 6, 6-20, > 20], laboratory results, number of Ra-223 doses, systemic treatment lines after radium-223, use of bone protecting agents (BPA) and survival outcomes were collected. OS and progression-free survival (PFS) were estimated by Kaplan-Meier (log-rank) analysis. Uni- (UVA) and multi-variate (MVA) analysis (Cox-regression) were used to evaluate patient and disease characteristics, number of Ra-223 doses and overall survival. Results: 114 men received Ra-223 between May 2015 and May 2018 with median age 75 years (range 53-93). Median radium doses was 5 (68 [59.6%] received > 4 doses, 46 [40.4%] received ≤4 doses). Median baseline ALP 113.5 U/L (31-1121), median baseline Hb 118 g/L (69-153), median baseline PSA 70.2 ug/L (0.15-5275), median LDH 242 UL (82-1426). 58% had 6-20 bone metastases and 28% had > 20 bone metastases. The median OS and PFS for men who received ≤4 doses vs > 4 doses was 4.56 vs 19.8 months (HR = 8.4; 95%CI: 4.861-14.62; p≤ 0.0001) and 2.9 vs 7.45 months (HR = 4.6; 95%CI: 2.837 to 7.537; p≤ 0.0001) respectively. The baseline median ALP was (154 vs 98; p = 0.03) for men who received ≤4 doses vs > 4 doses Ra-223. On UVA, ECOG 0-1 (HR = 0.33; p = 0.0003), baseline PSA < 70 ug/L (HR = 0.51; p = 0.0023), LDH < 250 U/L (HR 0.55; p = 0.0082), Hb > 120 g/L(HR 0.46; p = 0.0004), ALP < 150 U/l(HR 0.38; p ≤ 0.0001) and receipt of subsequent treatment after Ra-223 (HR = 0.33; p < 0.0001) were associated with improved OS. On MVA, receipt of subsequent treatment, administration > 4 cycles of Ra-223 and baseline ALP < 150 U/L were associated with improved OS. Conclusions: Men who receive > 4 cycles of Ra-223 have significantly better OS than those who receive ≤4 doses. Baseline ALP was independently associated with better OS and could be used to identify patients most likely to benefit from Ra-223.

IMPACT of putative chemopreventative agents on prostate cancer diagnosis

e16553

Background: Prostate cancer (PC) is the most common non-cutaneous cancer in men and the third most common cause of cancer death in males. Several studies have shown that use of commonly prescribed medications, is associated with improved survival in various malignancies, including PC. There has not been any large population-based study, examining the effects of these and other commonly prescribed medications, such as proton pump inhibitors (PPI), on the rate of PC diagnosis, PC advanced disease and PC-specific death. Methods: A retrospective population-based study using data from the institute of clinical evaluative sciences, including all male patients aged 65 and above in Ontario who have had a negative first prostate biopsy between 1994 and 2016. We assessed the impact of commonly prescribed medications on PC outcomes. The analyzed medications included Statins (hydrophilic and hydrophobic), most commonly used diabetes drugs (metformin, insulins, sulfonylureas, and thizolidinedions), PPIs, 5 alpha reductase inhibitors, and alpha blockers. Time dependent Cox regression proportional hazards models were performed to determine predictors of PC diagnosis, PC advanced disease (defined as usage of hormonal therapy), and PC-specific death. Medication exposure was time varying and modelled as “ever” vs. “never” use or as cumulative exposure. Results: A total of 21,562 men were analyzed over a mean (SD) follow-up time of 8.06 (5.44) years. Overall, 5,187 patients (24%) were diagnosed with PC, 7861 (36.5%) had died, and 647 (3%) died of PC. On multivariable analysis usage of hydrophilic statins modelled as “ever vs. never” was associated with a lower diagnosis rate (OR 0.832, 95% CI 0.732-0.946, p = 0.005) and a significantly decreased PC-specific death (OR 0.676, 95% CI 0.528-0.871, p = 0.0024). In contrast, Pantoprazole was associated with a higher rate of advanced PC disease when modelled as cumulative exposure of 6 months (OR 1.03, 95% CI 1.003-1.06, P = 0.031), and PC-specific death, when modeled as “ever vs. never” (OR 1.26, 95% CI 1.02-1.576, p = 0.031). Conclusions: Hydrophilic statins were associated with a clinically and statistically significant lower PC diagnosis and PC-specific death, while pantoprazole was associated with a higher rate of advanced PC disease and PC-specific death.

Validating the Cancer and Aging Research Group (CARG) toxicity prediction tool in older men receiving chemotherapy for metastatic castration-resistant prostate cancer (mCRPC) and extending it to androgen receptor targeted agents

11510

Background: Multiple treatment options are available for mCRPC. Being able to predict toxicity risk for different treatments in older adults can aid treatment decision-making and supportive care. The CARG tool is a promising toxicity risk prediction tool for chemotherapy, but has not been specifically validated in the mCRPC setting for either chemotherapy or androgen receptor targeted agents. We prospectively evaluated the ability of the CARG tool to predict risk of clinically relevant grade 2 and grade 3+ toxicity of treatment with chemotherapy (CHEMO) and abiraterone or enzalutamide (A/E) in older adults with mCRPC. Methods: Men age 65+ were enrolled in this prospective observational study at 3 academic centres, Princess Margaret Cancer Centre, Sunnybrook Health Sciences Centre, and Kingston Health Sciences Centre in Ontario, Canada. All grade 2 and grade 3+ toxicities were documented during cycle 1 of CHEMO or in the first 3 months of A/E via structured interviews and chart review. Lab abnormalities were documented only if resulting in emergency room visits, requiring treatment, or affecting subsequent oncologic treatment. Toxicity was rated using the Common Terminology Criteria for Adverse Events version 4. Logistic regression was performed to identify predictors of toxicity. Results: 64 men starting CHEMO (primarily docetaxel 60-75 mg/m^2, mean age 73y) and 59 men starting A/E (mean age 76y) were included. Clinically important grade 2 toxicities occurred in 86% and 70% of CHEMO and A/E patients, respectively. Grade 3+ toxicities occurred in 48% and 25% of CHEMO and A/E patients, respectively. The CARG tool was predictive of grade 3+ toxicities with CHEMO, which occurred in 22%, 53%, and 71% of low, moderate, and high risk groups (p = 0.017). However, the CARG tool was not predictive of grade 2 toxicities with CHEMO, or grade 2 or 3+ toxicities with A/E (Table). Conclusions: We provide external validation of the CARG tool in predicting grade 3+ toxicity in older men with mCRPC undergoing CHEMO. Grade 2 toxicities are very common with both CHEMO and A/E, and grade 3+ toxicity occurs in 1 in 4 older men on A/E. Additional efforts to identify men at higher risk of toxicity from various mCRPC treatments are warranted. [Table: see text]

Preoperative trial of neoadjuvant abiraterone plus or minus cabazitaxel: Early results

98

Background: High-risk prostate cancer (PC) has a significant risk of recurrence when treated with unimodal therapy. The utility of neoadjuvant therapy, prior to RP has yet to be defined. The Princess Margaret Cancer Centres’ ACDC study investigates the application of agents used for castration resistant PC in the neoadjuvant setting by comparing the use of abiraterone (AA) + prednisone (P) + leuprolide (LHRH) with or without cabazitaxel (CA) prior to RP in 76 high-risk patients. Herein, we report early results and protocol modifications. Methods: This phase II trial will randomize patients to two treatment arms: Arm A (AA/P + LHRH + CA 25 mg/m2 with peg-filgrastim 6 cycles) or Arm B (AA/P + LHRH) for 6 months prior to RP. The primary objective is to compare the pathological complete response (CR) between the treatment arms. We present the RP outcomes and safety data for the first 13 participants. Results: Out of 13 randomized participants, 10 completed study procedures and underwent RP. One participant (Arm B) completed study drug treatment, but opted for radiation therapy, while 2 participants (both in Arm B) were discontinued due to hepatoxicity. At RP, 2 participants exhibited CR (1 in each group) and an additional 3 patients exhibited near CR (less than 5% tumor volume). The Table demonstrates patient characteristics, pathologic results and Grade 3 adverse events rates. Of note, 2 patients (both in CA arm) developed post-operative thrombo-embolic events post RP and two experienced febrile neutropenia. Conclusions: Early findings indicate significant tumor response with 50% of patients exhibiting CR or near CR. Reduction in dosage of Cabazitaxel to 20 mg/m2 as well as need for extended post-operative thromboembolic prophylaxis have been implemented. ACDC early outcomes. [Table: see text]

The impact of intratumoral heterogeneity on prognostic biomarkers in localized prostate cancer

46

Background: Genomic biomarkers can identify patients that harbour aggressive disease. The utility of these biomarkers is uncertain due to genomic variation between prostate biopsy specimens. To quantify the robustness of genomic biomarkers, we performed spatio-genomic characterization of distinct tumor foci. We scored three validated DNA-based biomarkers of early biochemical recurrence: percentage of genome with a copy number aberration (PGA), a 100-loci biomarker, and an optimized 31- loci biomarker derived from the previous. For each biomarker, we determined their robustness to intratumoral heterogeneity in association with predicting early biochemical recurrence (eBCR; ≤18 months) and long term control (LTC; ≥48 months). Methods: We queried a registry of 1054 patients with high-risk prostate cancer who underwent a radical prostatectomy (RP). We developed a cohort (n = 42) risk matched by clinicopathologic prognostic indices. Half of the patients had eBCR, while the other half had LTC. We profiled multiple tumor foci per patient, analyzing 119 tumor foci. For each focus, CNA profiles were generated, and three biomarker scores were calculated. For each patient and biomarker, we calculated the score of the lowest-score region, the highest-score region, or sampling of all foci and use the mean score. Results: All three biomarkers distinguished LTC from eBCR. PGA scores separated the two groups with an area under the receiver operator curves (AUC) ranging from 0.75-0.80. The 100- and 31-loci signatures, had AUCs ranging from 0.76-0.85 and 0.76-0.80 respectively. Using Cox proportional hazards modeling, we found that PGA was associated with LTC (Hazard ratio (HR) range: 2.56-6.22; p < 0.05. This was replicated for the 100-loci signature (HR range: 3.55-5.23; p < 0.05). The 31-loci detected associations with eBCR independent of how different foci were summarized (log-rank p-value range: 5.1 x 10-4- 5.9 x 10-3). Conclusions: Despite divergence in biomarker scores, all three predicted eBCR. Our study suggests that genomic biomarkers can overcome intratumoral heterogeneity, making discrete samples potentially adequate in patients with high-risk disease to determine the risk of eBCR after radical treatment.

Do elderly men (>75) harbor more aggressive prostate cancer? Comparison of decipher and PAM50 TESTS among different age groups

38

Background: Age is an important prognostic factor in oncology. Over 20% of men diagnosed with prostate cancer (PC) are ≥ 75 years old. In the growing elderly population, objective methods for predicting outcomes beyond chronologic age are necessary in order minimize the likelihood of withholding curative treatment when warranted. Herein, we describe and analyze age-related differences in clinico-genomic prognostic indices of aggressiveness in localized PC. Methods: Clinical and genomic data for 8,355 patients from the Decipher Genomic Resource Information Database was obtained. Conventional and genomic prognostic indices including Decipher GC scores, PAM50 molecular subtypes (e.g. luminal A/B or basal) NCCN risk groups and Gleason groups (GG) were stratified by age using multivariable logistic regression analyses (MLRA). Results: With increasing decile of age, we observed a higher proportion of high GG and higher Decipher scores. There was a statistically significant increase in the proportion of patients with high Decipher scores with increasing age among GG1 and GG2 (< 55-10.2%, 30.7%, 55-60-15.4%, 25.6%, 60-65-15.9%, 29.7%, 65-70-16.9%, 28.2%, 70-75-17.9%, 30%, and > 75-20.3%, 37.3%, respectively). Furthermore, the prevalence of the PAM50 luminal B subtype (associated with worse prognosis) increased with age among GG1 and GG2 (< 60-22.2%, 40%, 60-65-29.1%, 41.7%, 65-70-28.2%, 39.2%, 70-75-30%, 43.4%, 75-80-33.5%, 44.3%, > 80-34.2%, 52%, respectively). Among higher grade tumors (GG 3-5), no statistically significant differences between the different age groups were observed. MLRA demonstrated that in addition to higher T stage, PSA and GG, each age decile entailed a 20% increased risk for a high Decipher score (OR 1.2, 95% C.I 1.11-1.3, p < 0.001). Conclusions: Older men with lower grade tumors, as opposed to higher grade tumors, harbored worse disease based on genomic risk models. The accepted paradigm of elderly PC patients being treated conservatively based solely on chronologic age, needs to be changed. We provide evidence suggesting the utility of clinical-genomic characterization for better treatment individualization decisions. (GRID; NCT02609269).

Impact of putative chemopreventative agents on prostate cancer diagnosis

40

Background: Prostate cancer (PC) is the most common non-cutaneous cancer in Canadian men and the third most common cause of cancer death in Canada. Several studies have shown that use of commonly prescribed medications, including those used for diabetes and hypercholesterolemia, is associated with improved survival in various malignancies, including PC. There has not been any large population-based study, examining the effects of these and other commonly prescribed medications, on the rate of PC diagnosis, over a 20 years follow-up period. Methods: A retrospective population-based study using data from the institute of clinical evaluative sciences, including all male patients aged 65 and above in Ontario who have had a negative first prostate biopsy between 1994 and 2016. We assessed the impact of commonly prescribed medications on PC diagnosis. The medications included Statins (hydrophilic and hydrophobic), diabetes drugs (metformin, insulins, sulfonylureas, and thizolidinedions), proton pump inhibitors, 5 alpha reductase inhibitors, and alpha blockers. Time dependent Cox regression proportional hazards models were performed determine predictors of PC diagnosis. Medication exposure was time varying and modeled as “ever” vs. “never” use or as cumulative exposure for 6 months of usage. A priori variables included in the model included age, ADG comorbidity score, rurality index, index year, and all medications. Results: A total of 51,415 men were analyzed over a mean (SD) follow-up time of 8.06 (5.44) years. Overall, 10,466 patients (20.4%) were diagnosed with PC, 16,726 (32.5%) had died, and 1,460 (2.8%) patients died of PC. On multivariable analysis increasing age and rurality index were associated with higher PC diagnosis rate, while a more recent index year, and usage of hydrophilic statins was associated with a lower diagnosis rate in both “ever” vs. “never” and cumulative models (HR 0.832, 95% CI 0.732-0.946, p = 0.005, HR 0.973 95% CI 0.951-0.995, p = 0.016, respectively). Conclusions: Hydrophilic statins are associated with a clinically significant lower PC diagnosis. To our knowledge this is the first study demonstrating a clear advantage of one group of statins (hydrophilic) over another (hydrophobic) in PC prevention.

Preliminary results of a two stage phase II study of 18F-DCFPyL PET-MR for enabling oligometastases ablative therapy in subclinical prostate cancer

250

Background: Despite maximal local therapies (MLT) (radical prostatectomy followed by radiotherapy [RT]), 20-30% of men will have incurable progression of prostate cancer (PC). Most recurrences in this scenario are characterized by continuous PSA rises and failure of standard imaging (bone scan [BS] and computed tomography [CT]) to detect recurrence sites. We conducted a phase II trial for men with rising PSA after MLT using 18F-DCFPyL PET-MR followed by targeted ablation of PET positive foci. We report the results of our pre-defined analysis. Methods: Patients with rising PSA (0.43.0 ng/mL) after MLT, negative BS/CT and no prior salvage ADT were eligible. All patients underwent 18F-DCFPyL PET-MR followed by immediate PET-CT acquisition. Those with limited disease, where possible, underwent stereotactic ablative RT (SABR) or surgery. No ADT was used. The primary endpoint was biochemical response rate (complete [undetectable PSA] or partial [PSA decline ≥50% compared to baseline]). A Simon’s two stage study design was employed. Stage 1 included 12 response evaluable patients, requiring 1 or more responses in the absence of grade 3+ toxicities to proceed to stage 2 (additional 25 response evaluable patients). Results: After a median of 58 months (range 29-120) post MLT, 20 patients underwent PET-MR/CT to have 12 response evaluable patients. Median PSA at enrollment was 1.3 ng/mL (range 0.4-2.8). Three patients had negative PET-MR/CT, while 17 had positive scans, of which 12 (60%) were amenable to response evaluable ablation. The median number of detected lesions in those treated was 2 (range 1-5). Ten patients underwent SABR (27-30 Gy/3 fractions) and 2 had surgery. One patient (8%) had complete and 4 (33%) had partial PSA responses at a median of 3.3 months (range 2.8-6.0) after ablation, while the remaining 7 (59%) did not have biochemical response. No grade 3+ toxicities were observed. Conclusions: 18F-DCFPyL PET/MR has high detection rates in men with rising PSA after MLT. We observed favorable early results with SABR or surgery (41% RR). Trial completion will inform if this approach offers potential for cure in an early molecularly-defined PC oligometastatic state. Clinical trial information: NCT03160794.

A phase I pilot study of preoperative radiotherapy for prostate cancer: Long-term toxicity and oncologic outcomes

60

Background: Pre-operative radiotherapy (PreORT) improves local control in various cancer types, and has become an established oncologic treatment strategy. During 2001-2004, we conducted a phase I pilot study assessing the role of short-course PreORT for men with unfavourable intermediate- and high-risk localized prostate cancer (PCa). We present long-term follow-up toxicity and oncologic outcomes. Methods: Eligible patients had histologically proven PCa, cT1-T2N0M0, PSA > 15-35 ng/ml with any Gleason score, or PSA 10-15 ng/ml with Gleason score ≥7. Patients received 25 Gy in five consecutive daily fractions to the prostate, followed by radical prostatectomy (RadP) within 14 days after RT completion. Primary outcomes were intra-operative morbidity, and late genitourinary (GU) and gastrointestinal (GI) toxicities. Acute toxicity was assessed during radiotherapy treatment on daily basis using RTOG grade scoring scale. Patients were assessed post-RadP clinically and with PSA at 1 and 6 months, and every 6 months. Intra- and Post-RadP toxicity was documented prospectively and scored as per Common Terminology Criteria for Adverse Events v4.0. Biochemical failure (BF) was determined based on two consecutive post-RadP PSA > 0.2 ng/ml. Results: Fifteen patients were enrolled; 14 patients completed PreORT followed by RadP, which also included bilateral lymph node dissections in 13 cases. Median follow-up was 12.2 years (range 6.7-16.3 years). Late GU toxicity was common, with 2 patients (14.3%) experiencing G2 toxicity, and 6 patients (42.8%) G3 toxicity. There were no G4-5 late GU toxicity. Late GI toxicity was infrequent, with only 1 patient (7.1%) experiencing transient G2 proctitis. At last follow-up, 8 (57.1%) and 6 (42.8%) patients experienced BF and metastatic disease recurrence, respectively. Conclusions: The use of PreORT in men with high-risk PCa is associated with unexpected high-rates of late GU toxicity. Future studies examining the role of RT pre-RadP must cautiously select RT technique and dose schedule. Importantly, long-term follow-up data is essential to fully determine the therapeutic index of PreORT in the management of localized PCa. Clinical trial information: NCT00252447.

The association between physician trust and prostate specific antigen screening: Implications for shared decision making

13

Background: Most cancer organizations recommend shared decision making for PSA screening, a process relying on a trusting relationship between patient and physician. The objective of this study was to assess the degree to which an individual’s trust in cancer information from their physician compared to internet-based information impacts the likelihood of receiving PSA-screening. Methods: This was a cross-sectional study (2011-2014) of the Health Information National Trends Survey (HINTS), a survey of people living in the US. The primary exposure was degree of trust in cancer information from participant’s physician (CIP). The secondary exposure was degree of trust in cancer information from the internet (CII). The primary outcome was patient-reported receipt of PSA-screening. The Cochran-Armitage test was used to identify significant trends in the primary outcome, across levels of trust. A multivariable logistic regression model assessed the association between CIP and CII with PSA-screening, adjusted for a priori covariates. Results: Among 5069 eligible respondents, 3,606 (71.1%) reported trusting CIP ‘a lot’, 1,186 (23.4%) ‘some’, 219 (4.3%) ‘a little’, and 58 (1.1%) ‘not at all’. 2,655 (52.4%) men received PSA-screening. The degree of trust in CIP was strongly associated with the likelihood of receiving PSA-screening: among men who reported ‘a lot’ of trust, 54.9% underwent screening, 48.6% ‘some’ trust, 38.4% ‘a little’ trust, and 27.6% among men ‘not at all’ trusting their physician (trend p < 0.0001). The degree to which men trusted CII was also associated with having received PSA-screening (p = 0.005), albeit with an insignificant trend (p = 0.07). After multivariable adjustment, these significant results persisted for degree of CIP trust (vs ‘a lot’: ‘some’ OR 0.80, 95%CI 0.66-0.97; ‘a little’ OR 0.61, 95%CI 0.41-0.90; ‘not at all’ OR 0.33, 95%CI 0.15-0.73), but not for trust in CII. Conclusions: The level of trust an individual has in their physician is strongly associated with undergoing PSA-screening. As rationale implementation of PSA screening requires shared decision-making, the level of physician trust has implications for dissemination of PSA-screening guidelines.

Can free PSA be used as a biomarker in biochemical recurrence after surgery to predict castrate resistant prostate cancer?

177

Background: PSA produced from prostate cancer (PC) cells escapes proteolytic processing, resulting in a more complexed PSA and a lower %fPSA. Higher %fpsa correlates with lower PC risk. However, the role of fPSA in biochemical recurrence (BCR) after radical prostatectomy (RP) is unknown. Methods: All patients who had BCR after RP and at least one fPSA test, were included. Patients were stratified according to the %fPSA cut-off of 0.15. Multivariable logistic regression analysis was performed to predict covariates associated with a higher %fPSA. Results: A total of 81 men with BCR were found (Table 1). Interestingly, 20% (group 1) vs. 60% (groups 2) become castrate resistant (CRPC), p<0.0001 and the time to reach CRPC state was much shorter in group 2 (33.5 months) vs. group 1 (57.9 months), p=0.05. Additionally, 60% of group 2 patients vs. 32.5% of group 1 patients developed metastasis, p=0.014. Lastly, median survival of 193 months for group 2 patients with no median survival for group 1, Log Rank test p=0.023. Multivariable logistic regression analysis demonstrated that secondary Gleason score of 5 (compared to 3) and %fPSA>0.15 predicted CRPC status (OR 11.63, CI 95% 1.38-97.4, p=0.024, OR 7.99, CI 95% 2-31.95, p=0.003, respectively). Conclusions: %fPSA>0.15 in the setting of BCR confers a more aggressive disease, manifesting in a faster development of CRPC, metastasis and death. Our findings suggest a reversal in the significance of % fPSA values in BCR patients, and should be validated in larger cohorts. [Table: see text]

RNA-sequencing to identify three different molecular grades and immune checkpoint cascades with distinct clinical behaviour in NMIBC

412

Background: NMIBC has a highly variable clinical behavior not adequately predicted by histological grade or clinical parameters. Some are indolent; others quickly progress to MIBC. Discrepancies between phenotype and genotype is compounded further by interobserver variability in pathological grading. There is an unmet need to improve the prediction of NMIBC. Methods: Whole transcriptomic analysis of 178 bladder tumors (158 NMIBC, 20 MIBC/metastatic) was performed from FFPE tissue incorporating messenger RNA expression, splice variants, gene fusion, mutation detection and immune checkpoint inhibitor cascades. CTLA, PD-1, LAG3, TIM3, TIGIT and B7 were compiled as an index including all major cascade genes. Data were integrated and tested for correlations with pathological grading and clinical outcomes. Conventional pathological grading for WHO 1973 (Grade 1, 2, 3) and 2004 (LG vs HG) classifications was reviewed by 3 expert uro-pathologists. Kappa statistic for interobserver variability was calculated. For validation we used an independent RNA-seq dataset (n = 209, Hedegaard et al. 2016 Cancer Cell). Results: Unsupervised clustering of RNA-Seq data distinguished 3 molecular subtypes of NMIBC; Molecular Grade Related Index (MGRI) 1, MGRI2, MGRI3. MGRI1 comprised of almost exclusively LG tumors. MGRI3 clustered with HG MIBC. Kappa for interobserver variability of expert pathologists was 0.40 and 0.78 in 1973 and 2004 WHO classification, respectively. FGFR3 mutations, FGFR3::TACC3 fusion events and MGRI1 genes were associated with components of xenobiotic metabolism (p = 2.51x10-09) signalling systems, in particular, GTPase regulation (p = 0.002), respiratory cycle genes (p = 0.004), HOX cluster (p = 0.005). MGRI independently predicted progression to MIBC (n = 138, HR = 2.96, 95%CI = 1.70-5.13, p = 1.20x10-04). 5-year PFS in a combined data set (n = 347) differed significantly for MGRI1 (100%) vs MGRI2 (92.2%) vs MGRI3 (73.5%, p = 1.99x10-05, Gray’s test). PD-1 ICC independently predicted progression (OR = 2.85, p < 0.05). Conclusions: RNA-seq delineates 3 molecular classes of NMIBC with different risks of progression to MIBC compared to conventional histologic grading.

Nuclear factor-kappa B p65 evaluation on the Canadian Prostate Cancer Biomarker Network (CPCBN) TMA-series for biomarker validation

80

Background: The CPCBN has assembled a TMA-based resource comprising the specimens of 1512 prostate cancer patients treated by radical prostatectomy. This richly annotated and multi-institutional resource is available to researchers who wish to access a large cohort to validate prognostic biomarkers (http://www.tfri.ca/en/research/translational-research/cpcbn.aspx). Over the last decade, our laboratory demonstrated with an independent cohort (Gannon PO, et al. Eur J Cancer. 2013 Jul;49(10):2441-8, Labouba I, et al. PLoS One. 2015 Jul 17;10(7):e0131024), the reproducible association of nuclear factor-kappa B (NF-kB) p65 with patient’s risk of biochemical recurrence. Here, we evaluated the CPCBN TMA-series for p65 expression. Methods: Two independent observers scored the frequency of p65 nuclear localisation on digital images obtained after automated immunohistochemistry analysis of p65. Over the available minimum 3 cores of tumour tissue per patient, an average percentage of positive nucleus frequency was used. Statistical analyses were performed using SPSS software. Results: High nuclear frequency of NF-kB p65 (cut-off at 3%) was associated with an increased risk for patients to experience a biochemical relapse (p < 0.001; Exp(B) = 1.599; 95%CI = 1.321-1.937), develop bone metastasis (p = 0.007; Exp(B) = 2.126; 95%CI = 1.234-3.663)and die from their disease (p = 0.001; Exp(B) = 3.117; 95%CI = 1.55-6.266). In multivariate analyses, p65 also remained independent from clinical parameters (PSA, Gleason score and pTNM): biochemical relapse (p = 0.005; Exp(B) = 1.331; 95%CI = 1.092-1.623), bone metastasis (p = 0.033; Exp(B) = 1.82; 95%CI = 1.04- 3.158), mortality (p = 0.007; Exp(B) = 2.626; 95%CI = 1.298-5.312) Conclusions: Using a large cohort of Canadian men, our study reiterates the previous study linking NF-kB p65 with prostate cancer progression and highlights the suitability of CPCBN TMAs for biomarker validation. Our results also reveal the role of p65 as a predictor of bone metastasis development and prostate cancer-specific mortality.

A randomized study of enzalutamide in patients with localized prostate cancer undergoing active surveillance (ENACT)

TPS5097

Background: Prostate cancer (PC) patients (pts) who select active surveillance (AS) are a heterogeneous population with varying risks for disease progression. Studies have estimated that approximately 31–42% of pts electing AS have experienced disease progression (pathological or therapeutic) over 1.8 and 2.3 years. There is no evidence-based pharmacological intervention which has effectively lessened this progression event. Pharmacological intervention with enzalutamide (ENZ), an androgen receptor inhibitor approved for treatment of metastatic castration-resistant PC, may lessen this progression. The aims of this study are to evaluate the efficacy of ENZ versus AS alone for delaying time to progression in pts with clinically localized PC undergoing AS. This study examines the effects of ENZ on progression in a subset of pts with low- or intermediate-risk PC who would otherwise elect an AS protocol. Methods: This is a multicenter, randomized, open-label study (NCT02799745). Eligibility criteria include histologically confirmed prostate adenocarcinoma within 6 months of screening, low or intermediate risk PC (T1c−T2c, prostate-specific antigen [PSA] < 20, N0, M0, Gleason score ≤7 [3+4 pattern only]), Eastern Cooperative Oncology Group status ≤2 and estimated life expectancy > 5 years. Exclusion criteria include any prior PC intervention. Pts will be randomized to receive open-label oral ENZ 160 mg/day once daily or to AS during the 1-year study treatment period. After the first year, all pts will be followed for one additional year with no other intervention. All pts will undergo prostate biopsy at 1 and 2 years. The primary end point is time to PC progression (pathological or therapeutic). Secondary end points include safety, incidence of negative biopsies for cancer at 1 and 2 years, percentage of cancer positive cores at 1 and 2 years, time to PSA progression, incidence of secondary rise in serum PSA, and quality-of-life questionnaires. Exploratory end points include biomarker assessment and genomic analysis. Study enrolment commenced in June 2016, with study completion expected in March 2019. Planned total enrolment is 222 pts from ~60 United States/Canadian sites. Clinical trial information: NCT02799745.

A propensity score analysis of radical cystectomy versus bladder-sparing trimodal therapy in the setting of a multidisciplinary bladder cancer clinic

e16003

Background: Multidisciplinary management improves complex treatment decision making in cancer care, but its impact for bladder cancer (BC) has not been documented. While radical cystectomy (RC) is currently viewed as the standard of care for muscle-invasive bladder cancer (MIBC), radiotherapy-based, bladder-sparing trimodal therapy (TMT) combining transurethral resection of bladder tumor, chemotherapy for radiation sensitization and external beam radiotherapy has emerged as a valid treatment option. In the absence of randomized studies, we compared the oncological outcomes between patients managed by RC or TMT using a propensity-score matched cohort analysis. Methods: Patients seen in our multidisciplinary bladder cancer clinic (MDBCC) from 2008 to 2013 were retrospectively reviewed. Those who received TMT for MIBC were identified and matched (for gender, cT and cN stage, ECOG status, Charlson comorbidity score, treatment date, age, CIS, hydronephrosis) using propensity scores, to patients who underwent RC. Overall survival and disease-specific survival (DSS) were assessed with Cox Proportional hazards modeling and competing risk analysis, respectively. Results: 112 patients with MIBC were included after matching, 56 treated with TMT and 56 by RC. Median age was 68.0 years and 29.5% were cT3/cT4. At a median follow up of 4.51 years, there were 20 (35.7%) deaths (13 from BC) in the RC group and 22 (39.3%) deaths (13 from BC) in the TMT group. 5 year DSS was 73.2% and 76.6%, in the RC and TMT groups, respectively (p = 0.49). Salvage cystectomy was performed in 6/56 TMT patients (10.7%). Conclusions: In the setting of a MDBCC, TMT yielded survival outcomes similar to matched RC patients. Appropriately selected MIBC patients should be offered the opportunity to discuss various treatment options including organ-sparing TMT.

Abiraterone +/- cabazitaxel in defining complete response in prostatectomy (ACDC-RP) trial

TPS5095

Background: Given recent advances in the management of de novo metastatic hormone-sensitive prostate cancer with both docetaxel and abiraterone, as well as evidence of significant activity of cabazitaxel in the post-abiraterone castrate-resistant setting, we hypothesized that the addition of cabazitaxel to neoadjuvant abiraterone will improve pathological complete response rates by overcoming mechanisms of resistance in localized high-risk prostate cancer. Aim: To determine the relative efficacy of the addition of cabazitaxel to abiraterone in the neoadjuvant treatment of prostate cancer to achieve a complete response. Methods: Open label, randomized, 2-arm multi-centre, phase 2 clinical trial. Primary endpoint: Pathological complete response rate (pCR). Secondary endpoints: surgical outcomes (positive margins, extracapsular extension, seminal vesicle or nodal involvement), pharmacodynamic markers in residual tumour (apoptosis, androgen receptor expression, localization, and signaling), biomarkers (intra-prostatic androgen levels), and safety. Design: Study participants will be randomized in a 1:1 ratio to receive either: Arm A: Abiraterone (1000 mg/day), prednisone (5 mg b.i.d.), leuprolide (22.5 mg s.c. every 3 months), and cabazitaxel (25 mg/m2 starting at week 2, with 6 mg pegfilgrastim 24 h following cabazitaxel) or Arm B: Abiraterone (1000 mg/day), prednisone (5 mg b.i.d.) and leuprolide (22.5 mg s.c. every 3 months). Assessments will take place biweekly for the first 12 weeks, then monthly until the prostatectomy (scheduled for 24 weeks following start of treatment). Target accrual is 88 participants within 36 months. Study is powered to detect a 15% difference with 85% power, assuming a one-sided type 1 error rate of 20%. A 6 patient safety run-in is included. As of Jan 2017, 1 site is open in Canada, with 4 additional Canadian sites and 1 site in Australia pending. To date, 4 participants are randomized and undergoing treatment. ACDC-RP is an investigator-initiated trial led by the Princess Margaret Urology Trials Group with funding from Ontario Institute for Cancer Research (OICR) and in-kind contributions from Janssen and Sanofi. Clinical trial information: NCT02543255.

The role of lifestyle characteristics on prostate cancer progression in two active surveillance cohorts

BACKGROUND

Although much research has examined the relationship between lifestyle and prostate cancer (PCa) risk, few studies focus on the relationship between lifestyle and PCa progression. The present study examines this relationship among men initially diagnosed with low- to intermediate-risk PCa and managed with active surveillance (AS).

METHODS

Men enrolled in two separate AS programs were recruited for this study. Data regarding clinical, demographic and lifestyle characteristics were collected. Results were then compared between men whose disease remained low- to intermediate-risk and men whose disease progressed.

RESULTS

Demographic, clinical and physical characteristics were similar between comparative groups and cohorts, with the exception that age at the time of diagnosis and questionnaire was increased among men whose disease progressed. Lifestyle scores among men who remained low- to intermediate-risk were higher than those whose risk progressed; however, scores were only significant in one cohort on univariable analysis. On multivariable analysis, the only predictor of progression was age at diagnosis. Physical activity was consistently higher in both low risk groups, although this difference was insignificant. Consistent differences in other lifestyle variables were not observed.

CONCLUSIONS

Age remains an important predictor of PCa progression. Improving lifestyle characteristics among men initially managed with AS might help to reduce the risk of progression. Given the limitations of this study, more rigorous investigation is required to confirm whether lifestyle characteristics influence the progression of low- to intermediate-risk PCa.

Potential role for metformin in urologic oncology

Metformin is one of the most commonly used drugs worldwide. It is currently considered first-line pharmacological agent for management of diabetes mellitus type 2. Recent studies have suggested that metformin may have further benefits, especially in the field of urologic oncology. Use of metformin has been shown to be associated with decreased incidence and improved outcomes of prostate, bladder, and kidney cancer. These studies suggest that metformin does have a future role in the prevention and management of urologic malignancies. In this review, we will discuss the latest findings in this field and its implications on the management of urologic oncology patients.

5α-reductase inhibitors and the risk of grade reclassification for men with long-term follow-up on active surveillance for prostate cancer

92

Background: The role of 5α-reductase inhibitors (5-ARIs) in prostatic diseases remains controversial because of an FDA black box label. We have previously published on the impact of 5-ARIs in men managed with active surveillance (AS), demonstrating their protective effect against progression. However, the long-term safety of 5-ARIs in the setting of AS has never been described, thus we sought to assess this. Methods: This is a single-institution, prospectively maintained, retrospective cohort study comparing men taking a 5-ARI versus no 5-ARI while on AS for PCa. Pathologic progression was evaluated and defined as Gleason score > 6, maximum core involvement > 50%, or more than 3 cores positive on a follow-up prostate biopsy. Time dependent covariate analysis to account for time on AS but not on 5-ARI was conducted to diminish the likelihood of overestimating the benefit. To account for differences in prostate volume at baseline between 5-ARI and non-5-ARI groups sensitivity analyses were performed, restricting men in the non-5-ARI group to those with larger glands (volume > 40 ml). Kaplan-Meier analyses were conducted along with multivariable Cox proportional hazard regression modeling for predictors of pathologic progression. Results: The original cohort of 288 men on AS were analyzed. The median follow-up was 61.2 months (IQR: 29.8-95.24) with 124 men (43%) experiencing pathologic progression and 119 men (41.3%) abandoning AS. Men taking a 5-ARI experienced a lower rate of pathologic progression (24.3% vs 49.1%; p < 0.001) and were less likely to abandon AS (25.7% vs 46.3%; p = 0.002). On multivariable Cox proportional hazards analysis, lack of 5-ARI use was most strongly associated with pathologic progression (HR: 2.56; 95% confidence interval, 1.32-5.02). Sensitivity analyses done to account for gland size demonstrated that lack of 5-ARI use was still predictive of progression (HR: 2.76; CI, 1.45–5.25; p = 0.002). Importantly, 5-ARI use was not associated with increased risk of high-grade prostate cancer. Conclusions: 5-ARIs were associated with a significantly lower rate of pathologic progression and abandonment of AS in men with median follow-up of 5 years.

Impact of multidisciplinary bladder cancer care for muscle invasive bladder cancer: A propensity score matched analysis of survival outcomes

455

Background: We started in 2008 a Multidisciplinary Bladder Cancer Clinic (MDBCC), where complex bladder cancer patients are assessed concurrently by urologic and radiation oncologists, with support from medical oncologists. Patients have the opportunity to discuss various treatment options including radical cystectomy (RC) or bladder sparing trimodal therapy (TMT; endoscopic resection, radiotherapy and chemotherapy). Although reports have shown comparable outcomes of TMT to cystectomy, no direct comparison to RC has been published and no randomized studies are available. We report our long term outcomes of multidisciplinary care, comparing TMT to surgery using propensity-matched analyses. Methods: Patients seen in our MDBCC receiving TMT for MIBC from 2008 to 2012 were identified and matched, using propensity scores, to patients operated by RC. Matching occurred on age, ECOG status, Charlson comorbidity score, cT stage, cN stage and date of treatment. Overall survival (OS) and disease-specific survival (DSS) were assessed with Cox Proportional hazards modeling and competing risk analysis, respectively. Results: Between 2008 and 2012, 248 patients were assessed in the MDBCC. Of these, 162 (65%) had MIBC. Nearly half (80) opted for radiotherapy +/- concurrent cisplatin chemotherapy and 49 underwent full bladder preservation with TMT as their primary therapy. We matched 48 TMT patients with 48 RC patients with no imbalances. Median age of the cohort was 67.5 years with 29.2% cT3/cT4. With a median follow up time of 3.62 years, there were 19 (39.6%) deaths (7 from bladder cancer) in the RC group and 15 (31.3%) deaths (6 from bladder cancer) in the TMT group. 5 year DSS was 85.2% and 84.7% with TMT and surgery, respectively (p > 0.05). There was no statistically significant difference in DSS between the two groups (HR for TMT 1.31 (0.40-4.23), p = 0.66) or in OS (HR for TMT 0.77 (0.34-1.75), p = 0.53). Conclusions: Bladder cancer patients benefit from a multidisciplinary approach.. In selected patients with MIBC, chemo-radiation yields survival outcomes similar to matched RC patients. BC patients should be offered the possibility to discuss various treatment options.

Are we systemically under treating cisplatin-eligible patients with muscle invasive bladder cancer (MIBC) who are undergoing bladder preservation by chemoradiotherapy?

417

Background: Neoadjuvant chemotherapy (NC) improves survival in MIBC pts regardless of local management-cystectomy or chemoradiation. NC use with chemoradiation has been limited as these pts are often elderly, frail and cisplatin-ineligible. But, as more fit, cisplatin-eligible pts opt for chemoradiation it is critical that we re-evaluate the feasibility and outcomes of giving NC followed by chemoradiation. Methods: We reviewed 25 MIBC pts with cT 2-4 N 0-1 M 0, undergoing chemoradiation between 2008-2014 at the Princess Margaret and Durham Regional Cancer Centers. All pts received NC with gemcitabine-cisplatin (2-4 cycles) then external beam radiation (median dose 60Gy) with concurrent cisplatin. Toxicities were recorded using CTCAE v 3.0. Response and outcomes were assessed by cystoscopy and imaging. Median follow-up was 29.7 mos and 6 pts had < 2 yrs of follow-up. Kaplan Meier analysis was used for survival. Results: Main reasons for a chemoradiation approach were pt preference 15/25 (60%) and comorbidities 10/25(40%). At diagnosis, median age was 69 (49-85), 76% were male, all were ECOG PS 0/1, median CrCl was 58.5 ml/min and 7/25 (28%) had hydronephrosis. CIS was seen in 10/25 (40%), LVI in 3/25 (12%) and node positivity in 2/25 (8%). All but 1 patient completed planned NC, where main Grade 3/4 toxicities as expected were neutropenia and infection. All planned radiotherapy and 83% of planned concurrent chemotherapy was given. Maximal TURBT was done in 76%. Cystoscopically post NC, 12/15 (80%) had a CR, 1/15 (7%) had CIS, and 2/15 (13%) had residual disease. Of the 12 pts with a CR, radiologically 4/12 had a CR, 2/12 had a PR and 6/12 had SD. Four pts required salvage cystectomy for local recurrence, 4 pts developed metastases and have died. Median OS was not reached, but the 2 yr OS rate was 73.8% (95% CI 50.3-87.4%). Conclusions: NC followed by chemoradiation, showed cystoscopic CR rates of 80% post NC and 2 yr OS rates of 73.8% suggesting this approach should be considered in cisplatin-eligible MIBC pts undergoing chemoradiation. Comparing outcomes between matched MIBC pts receiving NC and then chemoradiation or cystectomy also appears warranted.

Molecular tumor grading of non muscle invasive bladder cancer based on whole transcriptome analysis

467

Background: There is an unmet need for a comprehensive genomic characterization of non muscle invasive bladder cancer (NMIBC). NMIBC comprise over 70% of all bladder cancers at presentation. They have highly variable clinical behavior that is not always adequately predicted on the basis of their histological grade (2004 World Health Organization low and high grade, LG-HG). The discrepancy between phenotype and genotype is compounded further by interobserver variability in pathological grading. We have previously established methods for whole transcriptome RNAseq from formalin fixed paraffin embedded tissues (FFPE). Methods: Whole transcriptomic analysis of 110 NMI FFPE BC both LG and HG was performed incorporating messenger RNA expression, splice variants, gene fusion, and pathway perturbation. We used a discovery (n = 40) and a validation cohort (n = 70). These data were integrated and tested for correlation with both pathological grading and clinical outcomes. Grade Risk Index (GRI) score quantifying how closely a patient's transcriptome is related to a reference set of LG NMIBC samples was established. Conventional pathological grading was reviewed by 3 different expert uro-pathologists and interobserver variability calculated. Results: Unsupervised clustering of data from RNA sequencing uncovered classification of three robust - - nonoverlapping, prognostically significant subtypes of NMIBC with distinct GRIs and signatures. When applied by expert pathologists, interobserver variability in histological grading was observed in 17.5%. In the intermediate group (GRI 0.13 to 0.19), pathologists disagreed in 37.5% whether BC was LG or HG. HG NMIBC clustered with MIBC. LG NMIBC in the intermediate GRI group included either very bulky tumors or extremely rare metastatic LG BC (n = 4). HG disease was associated with a shift in BMP signaling and a germ stem cell-like phenotype. Multiple components of the centromere complex and APOBEC3B were upregulated in HG BC. FGFR3::TACC3 fusion events were observed in LG NMIBC only (11.5%). Conclusions: Whole transcriptomic sequencing data delineated three molecular classes of NMIBC.

Association of baseline perineural invasion with shorter time to progression in men with prostate cancer undergoing active surveillance: Results from the REDEEM study

23

Background: Perineural invasion (PNI) on prostate cancer (PC) biopsies has been associated with disease upgrading among those undergoing radical prostatectomy. However, the clinical significance of PNI in men on active surveillance (AS) has been evaluated by a limited number of studies. Thus, we sought to evaluate the association of PNI with time to clinical and pathological progression in men with PC on AS. Methods: Retrospective analysis of 289 men 48 to 82 years old on AS for low-risk PC (T1c-T2a), Gleason ≤6, ≤3 positive cores, ≤50% of any core involved, prostate-specific antigen (PSA) ≤11ng/ml, life expectancy >5 years and follow-up data in the REduction by Dutasteride of clinical progression Events in Expectant Management study. Progression was divided in pathological (>3 positive cores, >50% core involvement or Gleason >6 in a repeat biopsy) or therapeutic (any treatment for PC) or both. Time to progression was analyzed with Kaplan-Meier plots, log-rank tests and Cox model adjusting for age, PSA density, percent cores involved, maximum core involvement and treatment. Results: A total of 11 (4%) patients had PNI on baseline biopsy. PNI was associated with higher tumor length and maximum core involvement (all P<0.05). PNI was not associated with patient’s age, race, PSA levels or density, percent or number of positive cores. After a median follow-up of 37 months, 125 (43%) patients developed progression. Of these, 95 (76%) patients had pathological and 30 (24%) had therapeutic progression. In univariable analysis, patients with baseline PNI had a shorter time to overall and pathological progression (HR=2.62, 95%CI=1.31-5.23, P=0.006 and HR=2.42, 95%CI=1.03-5.66, P=0.041, respectively). Similar results were obtained in multivariable analysis for overall and pathological progression (HR=2.26, 95%CI=1.10-4.68, P=0.028 and HR=2.13, 95%CI=0.88-5.13, P=0.092, respectively). Conclusions: Among patients with PC on AS, PNI is independently associated with shorter time to progression. Thus, PNI may be used to help select patients for AS and stratify them according to the risk of disease progression.

Essential experimental steps and estimates of renal carcinoma initiating cells

11127

Background: Rare cancer stem cells (CSC), proposed to be solely responsible for tumor propagation and re-initiation, are functionally identified as tumor-initiating cells (TIC) from ex vivo tumors using xenotransplantation and clonogenic limiting dilution assays (LDA). TIC have not previously been described from ex vivohuman clear cell renal cell carcinoma (ccRCC). Methods: Primary human ccRCC samples (n=120) from patients undergoing nephrectomy were processed and implanted as subcapsular fragments or cell suspension injection LDAs with Matrigel in NOD/SCID/IL2Rγ-/- (NSG) mice, and observed for at least 6 months. In vitro clonogenic LDAs assays were performed from primary cell suspensions and ccRCC cell lines. LDAs were supplemented with human stromal cells and proteins, and the Y-26732 ROCK inhibitor. Multiparametric flow cytometry and immunofluorescence were used to investigate tumor heterogeneity and cell viability. Results: ccRCC TIC appeared rare from injected suspensions, but xenografts engrafted frequently from tiny fragments, and clonogenic frequencies were 103-104greater than TIC frequencies, suggesting that LDAs underestimated ccRCC tumor cell potential. We systematically identified multiple methodological steps that distort quantitation and identification of ccRCC TIC. For example cell viability was highly variable prior to processing, disaggregation itself destroyed up to 99% of tumor cells, standard assays substantially overestimated tumor cell viability in suspensions, and supplementation with human extracellular cells or proteins, or inhibition of anoikis by Y-26732 increased clonogenic and TIC frequencies in cell lines and primary ccRCC suspensions. Annexin-V staining revealed that tumor cells were more apoptotic then normal stromal cells, and that tumor cells positive for CD44 (a putative CSC marker) were more viable than CD44- tumor cells. Conclusions: We describe multiple, unappreciated and largely unavoidable observational errors in essential methods used to study TIC in ccRCC. ccRCC TIC may be more common than appreciated. Re-examination of the CSC hypothesis in other solid tumors is warranted in view of these previously unexplored methodological biases.

National survey addressing the information needs of primary care physicians: Side effect management of patients on androgen deprivation therapy

OBJECTIVE

Androgen deprivation therapy (ADT) is a common treatment for prostate cancer with numerous side effects. We assess primary care physicians' (PCPs) knowledge of ADT side effects and their interest in increasing their knowledge in this area.

METHODS

A list of active Canadian PCPs was obtained using the Canadian Medical Directory. A cross-sectional survey was distributed to 600 randomly selected physicians. We collected PCPs' demographic information, experience with ADT management, knowledge regarding ADT side effects and desired sources for obtaining knowledge on ADT management.

RESULTS

In total, we received 103 completed questionnaires. Of these, 89% of PCPs had patients on ADT. One-third of respondents prescribed ADT and over half of them administered ADT annually. Thirty-eight percent felt their knowledge of ADT side effects was inadequate and 50% felt uncomfortable counselling patients on ADT. Many PCPs were less familiar with the incidence of functional side effects of ADT (i.e., hot flashes, fatigue and erectile dysfunction) compared to life-threatening side effects (i.e., cardiovascular events, metabolic syndrome, fractures). In terms of increasing their knowledge of ADT side effects, 82% of PCPs would use educational resources if they were available (52% and 32% preferred continued medical education [CME] events and educational pamphlets, respectively).

CONCLUSIONS

PCPs play an important role in managing ADT side effects. There is poor awareness of the prevalence of ADT side effects, and many are uncomfortable in managing these side effects. These areas may be addressed through CME programs and educational pamphlets.

Concurrent cisplatin and radiotherapy: Decision making, tolerability, and outcomes for patients treated in a multidisciplinary bladder clinic

320

Background: For select muscle invasive bladder cancer (MIBC) patients, a multimodal approach using transurethral resection of the bladder tumor (TURBT) followed by concurrent cisplatin and external beam radiotherapy (EBRT) provides a curative bladder-sparing alternative to cystectomy. Our aim was to review decision making, tolerability and outcomes for patients treated in a multidisciplinary bladder clinic. Methods: Between June 1998-June 2011, MIBC patients treated with TURBT and concurrent cisplatin (40mg/m2 weekly) with EBRT (60-66Gy in 30-33 fractions to the bladder and pelvis) were identified. Post-treatment cystoscopy was performed every 3 months with regular imaging. Results: A total of 64 patients were assessed; mean age 73 (43-89), 83% were male. The decision to attempt bladder-sparing was based on patient preference (58%), nonsurgical candidate (25%), or unknown (17%). Patients received a mean 5/6 weeks of cisplatin with the most common toxicity being a 14% overall risk of grade 0-1 renal toxicity by NCIC CTC criteria. All patients completed the prescribed EBRT. No patients experienced acute toxicity requiring cystectomy or causing death. At a median follow-up of 3.5 years, 50/64 (78%) patients were alive and had their own bladders, 7/64 (11%) were alive after cystectomy for recurrence, 7/64 (11%) died. Of the 24/64 (38%) recurrences: 3/64 (5%) had positive cytology/carcinoma in-situ and received intravesicle therapy; 1/64 (2%) had local superficial recurrence and underwent TURBT; 7/64 (11%) had local invasive recurrence requiring cystectomy; 13/64 (20%) had distant recurrence, 6 received chemotherapy and 7 were observed. Estimated disease free survival was 51%, and overall survival was 90% at 3.5 years. Conclusions: Bladder-sparing therapy with concurrent cisplatin and EBRT is a well-tolerated and effective approach with outcomes comparable to cystectomy in carefully selected patients. Prospective trials are required to delineate clinical and molecular factors to further triage patients into sub-groups who may benefit from bladder sparing with neoadjuvant/adjuvant chemotherapy or molecularly-targeted agents to improve survival.

Should follow-up biopsies for men on active surveillance for prostate cancer be restricted to limited templates?

OBJECTIVE

To investigate if prostate biopsy templates with fewer cores can be used during active surveillance (AS) for prostate cancer.

METHODS

At present, we use an AS protocol template (ASPT) consisting of 13-17 cores. We hypothesize in the setting of known cancer, sextant (6 cores) or standard extended (10-12 cores) templates, could be used with similar effect. We identified patients in our referral institution database (1997-2009) with entry prostate-specific antigen <10 ng/mL, stage ≤cT2, Gleason sum ≤6, ≤3 cores positive for cancer, <50% of single core involved, and age ≤75 years (N = 272). Patients fulfilling standard criteria for pathologic reclassification (N = 94) at any follow-up biopsy were selected for evaluation. By mapping tumor location on the pathologic reclassification determining biopsy, hypothetical scenarios of sextant or standard extended templates (SET) were compared with our ASPT and examined for frequency of cancer detection and pathologic reclassification.

RESULTS

For the 94 patients analyzed, the median number of cores taken was 9.7 (6-22) at baseline and 15 (14-17) for the reclassification biopsy. The median time between baseline and the pathologic reclassification determining biopsy was 15.4 months. Analysis of subgroupings showed that sextant template would identify 84% of cancers and 47.9% of the reclassification events, whereas SET detected 99% of cancers and 81.9% of patients who pathologically reclassified. When only considering Gleason sum ≥7 related progression events, SET found 16.2% less (n = 57) compared with ASPT (n = 68).

CONCLUSION

When monitoring patients on AS, a 13-17 core template detects more pathologic reclassification than standard sextant (18.1%) or extended (52.1%) biopsy templates.

Final results of a phase II study of neoadjuvant metformin in prostatic carcinoma

5070

Background: Metformin is an inhibitor of the complex 1 in the respiratory chain, and is widely used in diabetes due to its effect on reducing insulin resistance. It has also been recently described to have effects via AMPK on inhibiting the mTOR kinase. Significant preclinical and epidemiological studies suggest its role in chemoprevention. These actions provide significant rationale to evaluate its utility in prostate cancer. Methods: Men were required to have histologically confirmed prostate cancer involving at least 20% of at least 1 unfragmented biopsy core. Exclusion criteria included patients who were found to be on treatment with any drug used for the treatment of any form of diabetes, or patients that began treatment for any form of diabetes during the course of the study. Pts were treated with up to 500mg tid of metformin. The primary objectives were to demonstrate safety and tolerability of neoadjuvant metformin administration in men with prostate cancer and to document changes in phospho-AKT signalling indices. Results: 24 patients were enrolled with 21 patients evaluable; median age was 64 yrs (range, 45-70 yrs). Baseline characteristics included median PSA 6 ng/mL (range, 3.22-36.11ng/mL). Median duration of drug treatment was 41 days (range 18-81). No grade 3 adverse events were reported during treatment or radical prostatectomy that were related to metformin. Significant pre-and post changes were noted in serum IGF1 (p=0.02), fasting glucose (p=0.03), BMI (p<0.01) and waist/hip ratio (p<0.01). There was a trend for a PSA reduction (p=0.08). There were no correlations between any metabolic, morphometric or cancer-related serum indices. On a per patient analyses, metformin reduced a computerised relative ki67 proliferation index by an average of 29% (absolute difference of 1.4%) compared to the baseline biopsy (p=0.006). P-4eBP1 staining was also reduced as assessed by H-score (p<0.01) consistent with the ability of metformin to inhibit mTOR. Conclusions: Neoadjuvant metformin is well tolerated prior to radical prostatectomy and shows promising effects on proliferation and signaling indices. Further research is needed to define the clinical utility of metformin in prostate cancer. Clinical trial information: NCT00881725.

Metformin use and all-cause and prostate-cancer-specific mortality among diabetic men

5007

Background: To evaluate the association between cumulative duration of metformin use after prostate cancer diagnosis and all-cause and prostate cancer-specific mortality among diabetic patients. Methods: We used a population-based retrospective cohort design. Data were obtained from several Ontario health care administrative databases. Within a cohort of men over the age of 66 with incident diabetes who subsequently developed prostate cancer, we examined the effect of duration of anti-diabetic medication exposure, after prostate cancer diagnosis, on all-cause and prostate cancer-specific mortality. Crude and adjusted hazard ratios were calculated using a time-varying Cox proportional hazard model to estimate effects. Results: The cohort consisted of 3,837 patients. Median age (interquartile range IQR) at diagnosis of prostate cancer was 75 (72-79) years. During a median (IQR) follow up of 4.64 (2.7-7.1) years, 1,343 (35%) died, and 291 patients died of prostate cancer (7.6%). Cumulative duration of metformin treatment, after prostate cancer diagnosis, was associated with a significant decreased risk of prostate cancer-specific and all-cause mortality in a dose-dependent fashion. The adjusted hazard ratio, for prostate cancer-specific mortality was 0.76 (95% confidence interval, 0.64-0.89) for each additional six months of metformin use. The association with all-cause mortality was also significant but declined over-time from a HR of 0.76 in the first 6 months to 0.93 between 24-30 months. There was no relationship between cumulative use of other anti-diabetic drugs and either outcome. Conclusions: Increased cumulative duration of metformin exposure after prostate cancer diagnosis was associated with decreases in both all-cause and prostate-cancer-specific mortality among diabetic men.

VHL-mutant renal cell carcinomas contain cancer cells with mesenchymal phenotypes

4568

Background: To study “cancer stem cells” it is imperative to account for all stromal cell populations within the tumour. The existence of “cancer stem cells” in clear cell renal cell carcinoma (ccRCC) has not been examined in ex vivo patient samples. Methods: We established a multiplex flow cytometry (FC) antibody panel in ccRCC, which reliably identified stromal lineages including CD45+ immune, CD31+/CD144+ endothelial and fibroblast-marker-positive subpopulations, thus allowing isolation of "lineage-negative" tumor cells. To verify the identity of tumour-derived populations as either cancer cells or normal stromal cells, we took advantage of the fact that mutations in VHL occur early during ccRCC tumorigenesis and are found in two-thirds of patients. Results: We sequenced 18 patient tumor samples, 12 of which had VHL exome mutations. Targeted re-sequencing of FC sorted subpopulations from these patients’ samples revealed that while CD45+ immune cells and CD31+/CD144+ endothelial cells were genetically normal, a population of VHL-mutant fibroblast-marker positive cells was consistently identified in every patient’s tumour. Immunohistochemistry showed that fibroblast marker-positive VHL-mutant cells do not have the large “clear cell” morphology typical of the majority of the cancer cells in these tumours. When purified and cultured, these fibroblast marker-positive VHL-mutant cells proliferate extensively under mesenchymal culture conditions, but displayed different morphologies to lineage-negative VHL-mutant tumor cells. Functional characterization of these FC sorted cell subpopulations is ongoing, including proliferation, migration, invasion, differentiation and treatment resistance. Conclusions: The phenotype and preliminary functional characterization of these VHL-mutant fibroblast-marker positive cells suggests a mesenchymal differentiation program in ccRCC, with implications for the ontogeny, biology and clinical management of VHL-mutant renal cancer.

Comparison of serum testosterone levels in prostate cancer patients

Introduction: The prostate secretes enzymes and nutrients to promote sperm motility. Recent reports suggest that the prostate may also secrete testosterone, which is believed to be a fuel for prostate tumour growth. The aim of this study was to determine if a difference in serum testosterone levels exists between men on luteinizing hormone releasing-hormone (LHRH) agonists who have undergone radical prostatectomy, radiation or hormone therapy as primary prostate cancer treatment.Methods: Serum testosterone levels were evaluated in 165 consecutive prostate cancer patients using LHRH analogues for >3 months. We excluded patients receiving either radiation or chemotherapy at time of time of testosterone measurement. Patients were classified based on primary treatment: (1) radical prostatectomy; (2) radiation; or (3) primary hormone therapy. We used one-way ANOVA to compare testosterone levels. Pearson correlation was used to correlate testosterone with prostate-specific antigen (PSA) and time on LHRH agonists. Multivariable linear regression was used to predict serum testosterone levels.Results: The median (interquartile range) serum testosterone levels were 1.4 (1-1.9), 1.3 (1-1.625) and 1.25 (0.9-1.525) nmol/L for radical prostatectomy, radiation and primary hormone therapy groups, respectively. There was no statistically significant difference in testosterone levels between the groups (p = 0.3). No correlation was found between testosterone and PSA levels or time on LHRH (r = 0.02 and r = 0.01), respectively. Multivariable linear regression showed that none of the clinical variables were predictors ofserum testosterone levels.Conclusion: Our study suggests that primary treatment does notaffect serum testosterone levels among men using LHRH analogues.

Use of microRNA signature to distinguish early from late biochemical failure in prostate cancer

194

Background: With the introduction of PSA testing, the problem of over-treatment emerged in prostate cancer. Only a small subset of prostate cancer patients will require more intensive adjuvant therapy. There is currently no biomarker that can predict disease aggressiveness at the time of surgery. Methods: We analyzed miRNA expression in 41 patients (the discovery set) which were dichotomized into; 'high risk'- experienced biochemical failure within 24 months after radical prostatectomy (n=26) and 'low risk' who did not have biochemical failure for at least 35 months (n=15). The validation set consisted of 72 cases. Total RNA was isolated from FFPE cores. cDNA was prepared for each patients and expression miRNA expression was screened by qRT-PCR –based panel. miRNAs were ranked by non-parametric tests. Linear regression models were built to predict biochemical failure. We used TargetScan for miRNA target prediction. Targets were validated by transient transfection of synthetic miRNA precursors followed by qRT-PCR quantification of the targets. Proliferation was assessed by measuring cell viability. Results: We compared the expression of 754 mature human miRNAs in patients with ‘high’ or ‘low’ risk for biochemical failure. We identified 24 miRNAs that were differentially expressed between the risk groups. We developed three logistic regression models, based on the expression of 2-3 miRNAs (PPV=100% and NPV ranges 86.4-100%). We confirmed the differential expression on the study set and on a larger, independent set of PCa pateints. We also validated one model on an independent set of patients. Further, we show that transfection of miR-152 and miR-331-3p, featured in the logistic regression models, altered proliferation of PCa3 and DU145 cells. Target prediction indicated Erbb3 and Erbb2 as potential direct targets and their mRNA expression significantly reduced when miR-152 and miR-331-3p were overexpressed. Conclusions: Altered miR-331-3p and miR-152 expression represent a potential tool for assessing the risk of early biochemical failure. These miRNAs may act through the Erbb family to induce an alternative way of AR activation.

Comparison of serum testosterone levels in prostate cancer patients receiving LHRH agonist therapy with or without the removal of the prostate

INTRODUCTION

: The prostate secretes enzymes and nutrients to promote sperm motility. Recent reports suggest that the prostate may also secrete testosterone, which is believed to be a fuel for prostate tumour growth. The aim of this study was to determine if a difference in serum testosterone levels exists between men on luteinizing hormone releasing-hormone (LHRH) agonists who have undergone radical prostatectomy, radiation or hormone therapy as primary prostate cancer treatment.

METHODS

: Serum testosterone levels were evaluated in 165 consecutive prostate cancer patients using LHRH analogues for >3 months. We excluded patients receiving either radiation or chemotherapy at time of time of testosterone measurement. Patients were classified based on primary treatment: (1) radical prostatectomy; (2) radiation; or (3) primary hormone therapy. We used one-way ANOVA to compare testosterone levels. Pearson correlation was used to correlate testosterone with prostate-specific antigen (PSA) and time on LHRH agonists. Multivariable linear regression was used to predict serum testosterone levels.

RESULTS

: The median (interquartile range) serum testosterone levels were 1.4 (1-1.9), 1.3 (1-1.625) and 1.25 (0.9-1.525) nmol/L for radical prostatectomy, radiation and primary hormone therapy groups, respectively. There was no statistically significant difference in testosterone levels between the groups (p = 0.3). No correlation was found between testosterone and PSA levels or time on LHRH (r = 0.02 and r = 0.01), respectively. Multivariable linear regression showed that none of the clinical variables were predictors of serum testosterone levels.

CONCLUSION

: Our study suggests that primary treatment does not affect serum testosterone levels among men using LHRH analogues.

A phase II trial of neoadjuvant metformin in prostatic adenocarcinoma with serum and tissue biomarker evaluation

e15118

Background: Metformin is an inhibitor of the complex 1 in the respiratory chain, and is widely used in diabetes due to its effect on reducing insulin resistance. It has also been recently described to have effects via AMPK on inhibiting the mTOR kinase. Significant preclinical and epidemiological studies suggest its role in chemoprevention. These actions provide significant rationale to evaluate its utility in prostate cancer. We conducted a phase II single centre study of neoadjuvant metformin in localised prostate cancer. Methods: Men were required to have histologically confirmed prostate cancer involving at least 20% of at least 1 unfragmented biopsy core. Exclusion criteria included patients who on initial assessment are found to be on treatment with any drug used for the treatment of any form of diabetes, or patients that begin treatment for any form of diabetes during the course of the study. Pts were treated with up to 500mg tid of metformin. Primary objectives were to demonstrate safety and tolerability of neoadjuvant metformin administration in men with prostate cancer and document changes in phospho-AKT signalling indices. Results: 24 patients were enrolled with 22 evaluable; median age was 64 yrs (range, 45-70 yrs). Baseline characteristics included median PSA 6 ng/mL (range, 3.22-36.11ng/mL). Median duration of drug treatment was 41 days (range 18-81). No grade 3 adverse events were reported, all patients underwent subsequent radical prostatectomy with adverse effects related to metformin. Final Gleason scores ranged form 6-8, and final stage ranged from pT2a-pT3b. Significant pre-and post changes were noted in serum IGF1 (p=0.02), fasting glucose (p=0.03), BMI (p<0.01) and waist/hip ratio (p<0.01). There was a trend for a PSA reduction (p=0.08), with 6/22 patients experiencing a PSA fall of greater than 20%. There were no correlations between any metabolic, morphometric or cancer-related serum indices.Tissue results are pending. Conclusions: Neoadjuvant metformin is well tolerated prior to radical prostatectomy. Data to date indicates promising effects on metabolic parameters, tissue results will be presented including proliferation indices and signaling pathway assessments.

Prevalence of cancer-related fatigue in a population-based sample of colorectal, breast, and prostate cancer survivors

9131

Background: Cancer-related fatigue (CRF) is the most prevalent and distressing cancer-related symptom and has a greater negative impact on patients' daily activities and quality of life than other cancer-related symptoms, including pain and depression. However, the prevalence and severity of persistent CRF and related disability in the post-treatment survivorship period has seldom been examined in populations other than breast cancer. The primary objective of the study was to describe the prevalence of significant CRF and associated levels of disability in a mixed cancer population sample at 3 time points in the post-treatment survivorship trajectory. Methods: Based on cancer registry data, a self-administered mail based questionnaire using Dillman's Tailored Design Method was sent to 3 cohorts of disease-free cancer survivors (6-18 months; 2-3 years; and 5-6 years post-treatment) previously treated for non-metastatic breast, prostate or colorectal cancer. Fatigue was measured using the FACT-F and disability was measured with the WHO-Disability Assessment Schedule. Clinical information was extracted from chart review. Frequencies of significant fatigue by disease sites and time points were studied and compared using chi-square test. Disability between those with and without CRF was also compared using Cochran-Armitage trend test. Results: 1294 questionnaire packages were completed (63% response rate). The FACT-F score was 39.1+10.9; 29% (95% CI: [27%, 32%]) of the sample reported significant fatigue (FACT-F≤34) and this was associated with much higher levels of disability (p<0.0001). Breast (40% [35%, 44%]) and colorectal (33% [27%, 38%]) survivors had significantly higher rates of fatigue (≤34) compared to the prostate group (17% [14%, 21%]) (p<0.0001). Fatigue levels remained relatively stable across the 3 time points. Conclusions: CRF was a significant and debilitating symptom for a substantial minority of the respondents across all 3 time points. Effective CRF management strategies are needed and have the potential to significantly reduce morbidity associated with cancer and its treatments and to improve quality of life for the growing population of cancer survivors.

Impact of 36 months of androgen-deprivation therapy (ADT) on physical function and quality of life (QOL) in men with nonmetastatic prostate cancer

16

Background: Use of ADT has been shown to adversely affect physical function and QOL within 3 months of initiation; declines persist at 12 months. Few studies have examined physical function with ongoing ADT use beyond 12 months.

Methods: In this extension of our prior study, men age 50 or older with non-metastatic prostate cancer (PC) who were on continuous ADT were followed along with two control groups (PC, no ADT; healthy controls) matched on age, education, and baseline function. Physical function was assessed with the 6-minute walk test (6MWT), grip strength, and the Timed Up and Go (TUG) test, representing endurance, upper extremity strength, and lower extremity strength, respectively. Aggregate physical and mental QOL were measured with the Medical Outcomes Study SF-36. Assessments were done at baseline and at 3, 6, 12, 18, 24, 30, and 36 months. Mixed effects regression models were used, adjusting for age, baseline function, and other covariates.

Results: 87 patients on ADT, 86 PC controls, and 86 healthy controls were enrolled (mean age 69.4 y, range 50-87). At baseline, all three groups were similar in age and physical function (all ANOVA p>0.05) and most subjects were otherwise quite healthy. 6MWT distance improved in both control groups but remained unchanged in ADT users (p=0.0379). Grip strength declined sharply in the ADT group by 3 months and remained stable up to 36 months (p<0.001), whereas both control groups were stable over time. There was a slight worsening of TUG scores in the ADT group over 36 months (p=0.0003) but were unchanged in both control groups (p>0.10). Aggregate physical QOL continued to decline in ADT users over time (p=0.0002) but remained stable in both control groups over 36 months, whereas aggregate mental QOL was stable in all groups over time. Most declines were evident within 3-6 months of ADT initiation.

Conclusions: Initial declines with continuous ADT use in both physical function and aggregate physical QOL persist for 36 months but generally did not decline further beyond one year despite ongoing ADT use. Early exercise interventions and/or intermittent ADT use may improve these outcomes.

Impact of multiparametric endorectal coil prostate MRI on disease reclassification among active surveillance candidates: A prospective cohort study

30

Background: One troubling aspect of active surveillance (AS) is that a subset of patients diagnosed as very-low risk prostate cancer (PCa) appear to be under sampled and, in fact, harbour larger often higher grade cancers.The aim of this study is to report MRI findings among unselected men with low-risk PCa prior to AS.

Methods: We prospectively enrolled men with low-grade, low-risk, localized PCa. All patients underwent multiparametric endorectal coil MRI scanning and offered a confirmatory biopsy within one year of MRI. The primary outcome was the impact of MRI in identifying patients reclassified as no longer fulfilling AS criteria by a confirmatory biopsy. We further aimed to identify clinical parameters associated with reclassification. Cohort was stratified as follows: normal MRI; cancer on MRI concordant with initial biopsy (less than 1 cm); cancer on MRI larger than 1cm. We performed a univariate analysis to assess differences in clinical parameters between groups.

Results: MRI did not detect cancer in 23 (38%) while MRI and initial biopsy were concordant in 24 patients (40%). MRI detected a 1cm or larger lesion in 13 patients (22%). Eighteen patients (32.14%) reclassified. When no cancerous lesion was identified on MRI only 2 patients (3.5%) reclassified. The positive and negative predictive values for MRI predicating reclassification were 83% (95% CI, 73%-93%) and 81% (95% CI, 71%-91%), respectively. PSA density was elevated among patients with larger than 1 cm MRI lesions compared to those with no cancer on MRI (medians of 0.15 vs 0.07 ng/ml/cc, respectively p=0.016).

Conclusions: MRI appears to have a high yield in predicting reclassification among men choosing AS. Upon confirmation of our results MRI may be used to better select and guide patients before AS.

Impact of androgen deprivation therapy (ADT) on bone mineral density (BMD) over 3 years in men with nonmetastatic prostate cancer

193

Background: Decreased BMD is a common side effect of ADT, leading to increased fracture risk. Although loss of BMD appears to be greatest within the first 12 months of starting ADT, few data on BMD changes exist beyond 12 months, and other risk factors for bone loss in men on ADT are not well-characterized.

Methods: Men age 50+ with non-metastatic prostate cancer and starting continuous ADT were enrolled in a prospective longitudinal study. BMD was determined by dual-energy x-ray absorptiometry at baseline and yearly for 3 years. A matched control group of men with prostate cancer but not on ADT was also enrolled. Medication use was recorded at each visit. Multivariable regression analyses were done to examine predictors of BMD loss.

Results: 80 ADT users and 80 controls were enrolled (mean age 69.4 y); 49.7% had osteopenia and 4.6% had osteoporosis at baseline. ADT was associated with significant losses in lumbar spine BMD in year 1 compared to controls (p=0.004) and trends towards greater declines at femoral neck and total hip sites. Changes in year 2 and 3 were much smaller and not statistically different from controls (Table). Vitamin D use but not calcium use was associated with improved BMD at the lumbar spine in year 1 (+5.77%, p=0.006) with positive trends at other sites (+2.19% femoral neck, +1.76% total hip) primarily in year 1. Age was not associated with changes in BMD.

Conclusions: Losses in BMD with ADT use are greatest at the lumbar spine and in the first year compared to years 2 and 3 and are independent of age. Vitamin D appears to be protective particularly in the first year of ADT use.

[Table: see text]

Extended lymphadenectomy and adjuvant chemotherapy in muscle-invasive bladder cancer treated by radical cystectomy

287

Background: Level 1 evidence is weak for adjuvant chemotherapy (AC) after cystectomy, but surveys indicate physicians refer patients for AC more frequently than for neoadjuvant chemotherapy (NC). The exact benefit of an extended pelvic lymph node dissection (ePLND) remains debated. We addressed the issue of AC and ePLND analyzing two academic centers RC databases with opposite approaches, one using ePLND and AC, the other performing a limited lymph node dissection and no AC.

Methods: Two ethics approved RC databases including consecutive BC patients undergoing RC at the University Health Network, Canada and the University of Turku, Finland were studied. Excluding non-urothelial cases and patients receiving NC, 563 patients were available for analysis. Clinicopathological variables, rate and extent of PLND and rate of adjuvant cisplatin-based chemotherapy were analyzed using the χ2-test. Kaplan-Meier method and multivariate Cox regression analysis were used to analyze survival.

Results: In Toronto, patients had more extensive PLNDs (>10 nodes removed, 58% vs. 8%, p<0.001), higher rate of nodal metastases (26% vs. 7%, p<0.001), and received more often AC (21% vs. 1%, p<0.001). Positive margin rates were similar (4% in both centers). No BC specific survival difference was demonstrated in ≤ pT2a or in pT4a tumors. There was a trend for improved survival in pT2b tumors (10y BC specific survival 65% vs. 42%, p=0.23) and a significant difference favouring the Toronto cohort in pT3a and pT3b tumors (55% vs. 31%, p=0.025; 43% vs. 28% p=0.06, respectively). In multivariate analysis, N-stage (HR 2.5, 95% CI 1.5-4.1; p<0001) and ePLND (HR 0.53, 95% CI 0.31-0.93, p=0.026) significantly affected disease specific survival. The benefit of AC did not reach significance (HR 0.61, 95% CI 0.36-1.05, p=0.072). An interaction model combining ePLND and AC was significantly related to improved outcome (HR 0.49, 95% CI 0.26-0.92, p=0.026).

Conclusions: Despite not being randomized, using 2 study cohorts that received completely opposite managements in terms of ePLND and AC, our results support that ePLND and AC may offer a survival advantage in T2b and especially in T3 BC treated with RC.

Prevention strategies in prostate cancer

Prostate cancer (PCa) prevention has been an exciting and controversial topic since the results of the Prostate Cancer Prevention Trial (PCPT) were published. With the recently published results of the reduce (Reduction by Dutasteride of Prostate Cancer Events) trial, interest in this topic is at a peak. Primary pca prevention will be unlikely to affect mortality significantly, but the reduction in overtreatment and the effect on quality of life from the avoidance of a cancer diagnosis are important factors to consider.This review provides a comparative update on the REDUCE and PCPT trials and some clinical recommendations. Other potential primary preventive strategies with statins, selective estrogen response modulators, and nutraceutical compounds-including current evidence for these agents and their roles in clinical practice-are discussed. Many substances that have been examined in the primary prevention of pca and for which clinical data are either negative or particularly weak are not covered.The future of PCa prevention continues to expand, with several ongoing clinical trials and much interest in tertiary prostate cancer prevention.

Prostate Cancers Scored as Gleason 6 on Prostate Biopsy are Frequently Gleason 7 Tumors at Radical Prostatectomy: Implication on Outcome

PURPOSE

Differentiation between Gleason score 6 and 7 in prostate biopsy is important for treatment decision making. Nevertheless, under grading errors compared with the actual pathological grade at radical prostatectomy are common. We compared the characteristics and outcomes of tumors that were scored 6 on prostate biopsy but were 7 on subsequent radical prostatectomy pathological evaluation to those in tumors with a consistent rating of Gleason score 6 or 7 at biopsy and surgery.

MATERIALS AND METHODS

We performed a retrospective database analysis from our referral center (1989 to 2004). We compared pre-prostatectomy characteristics, radical prostatectomy pathological features and the post-radical prostatectomy prostate specific antigen failure rate, defined as any 2 consecutive detectable prostate specific antigen measurements, in 3 subgroups of patients, including 156 with matched Gleason score 6 in the prostate biopsy and radical prostatectomy, 205 with upgraded Gleason score 6/7, that is prostate biopsy Gleason score 6 and radical prostatectomy Gleason score 7, and 412 with matched Gleason score 7 in the prostate biopsy and radical prostatectomy.

RESULTS

Radical prostatectomy Gleason score matched the prostate biopsy score in 38.2% of biopsy Gleason score 6 and 81.4% of biopsy Gleason score 7 cases. Higher prostate specific antigen was associated and an increased percent of cancer in the prostate biopsy was predictive of discordance between the prostate biopsy and radical prostatectomy Gleason scores (p <0.001). Margin (p = 0.0075) or seminal vesicle involvement (p = 0.0002), cancer volume (p <0.001) and the prostate specific antigen failures rate (p = 0.014) were significantly higher in under graded Gleason score 7 cancer compared to those in matched Gleason score 6 cases. However, they were comparable to those with a matched Gleason score 7 tumor grade (p = 0.66).

CONCLUSIONS

Almost half of tumors graded Gleason score 6 at biopsy are Gleason score 7 at surgery. Upgraded Gleason score 6 to 7 tumors have outcomes similar to those of genuine Gleason score 7 cancer. For prostate biopsy Gleason score 6 tumors clinicians should consider the overall likelihood of tumor upgrading as well as specific patient characteristics, such as prostate specific antigen and the percent of tumor in the prostate biopsy, when contemplating treatments that are optimized for low grade tumors, including watchful waiting or brachytherapy.