Comparative real-world survival outcomes of muscle-invasive bladder cancer treated with bladder-only vs. whole-pelvis concurrent chemoradiation

INTRODUCTION

Elective pelvic nodal irradiation for patients with muscle-invasive bladder cancer (MIBC) undergoing trimodal therapy (TMT ) is controversial. In patients with node-negative (N0) MIBC, the benefit of elective whole-pelvis concurrent chemoradiation (WP-CCR) compared to bladder-only (BO )-CCR has not been demonstrated. Using real-world data from the National Cancer Database (NCDB ), we sought to compare the overall survival (OS ) between BO-CCR and WP-CCR for MIBC.

METHODS

Using the 2020 NCDB Participant User File, we identified cases of MIBC diagnosed between 2017 and 2019. We selected patients with clinical T2-T4aN0M0 disease receiving CCR as first-line treatment. CCR was defined as transurethral resection of bladder tumor followed by ≥40 Gy radiation to the bladder with concurrent single- or multiple-agent chemotherapy. Based on elective nodal irradiation status, patients were stratified as having received BO-CCR vs. WP-CCR. OS analysis was performed using summary three-month conditional landmark, inverse probability treatment weighting (IPTW)-adjusted Kaplan-Meier estimates, and Cox regression.

RESULTS

A total of 604 patients receiving CCR for MIBC were identified: 367 (60.8%) BO-CCR and 237 (39.2%) WP-CCR. Before IPTW, the groups were imbalanced in terms of baseline characteristics. The median followup of the weighted population was 42.3 months (interquartile range 18.1-49.1 months). In IPTW-adjusted Cox proportional hazards regression analysis, WP-CCR was associated with a significant OS benefit compared to BO-CCR (adjusted hazard ratio 0.72, 95% confidence interval 0.54-0.96, p=0.026).

CONCLUSIONS

In the setting of CCR for N0 MIBC, this retrospective NCDB analysis revealed that WP-CCR was associated with a benefit in OS compared to BO-CCR.

Chemotherapy, immunotherapy, or combination first-line treatment for metastatic urothelial carcinoma of the bladder: A large real-world experience

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Background: First-line therapy for metastatic urothelial carcinoma of the bladder (mUC) consists of platinum-based chemotherapy in most patients and PD1/L1 inhibitors in selected patients. Multiple combination chemo-immunotherapy trials failed to show a clear benefit over chemotherapy alone. We sought to use real-world data to evaluate clinical and sociodemographic factors associated with receipt of first-line chemotherapy, immunotherapy or combination chemo-immunotherapy treatment for metastatic bladder cancer and examined differences in overall survival (OS). Methods: We used the National Cancer Database to identify patients with stage IV UCB diagnosed between 2014 and 2018, who were treated with first-line immunotherapy, chemotherapy, or combination treatment. We performed multivariable logistic regression modeling to determine factors associated with treatment receipt. An extension of inverse probability treatment weighting (IPTW) obtained from multinomial logistic regression was used to balance clinical and sociodemographic differences between treatment groups. Adjusted Kaplan-Meier survival analysis and multivariable Cox proportional hazards regression were used to evaluate the association between treatment and OS. Results: A total of 4,169 patients were identified in the cohort; 3,255 (78.1%) were treated with chemotherapy, 601 (14.4%) with immunotherapy, and 313 (7.5%) with combination treatment. Multivariable analysis identified increasing age (RRR: 1.07, 95% CI, 1.06-1.08), comorbidity burden (Charlson-Deyo 2, RRR: 1.65, 95% CI, 1.21-2.24 and Charlson-Deyo 3, RRR: 2.11; 95% CI, 1.51-2.93), and treatment at an academic facility (RRR: 1.26; 95% CI, 1.03-1.53) as independent predictors of receiving immunotherapy. Treatment at an academic facility (RRR: 1.29, 95% CI, 1.01-1.65) was associated with receipt of combination treatment. After IPTW, we found that combination therapy (hazard ratio [HR]: 0.72; 95% CI, 0.62-0.83), but not immunotherapy alone, was associated with improved survival compared to chemotherapy. These data are limited by inability to determine platinum eligibility, and residual confounding. Conclusions: Patients with older age and more comorbidities were more likely to receive immunotherapy than chemotherapy for first-line treatment of metastatic urothelial carcinoma of the bladder. Modest real-world utilization of chemo-immunotherapy was observed to be higher in academic centers and was associated with improved survival compared to chemotherapy. The study is limited by retrospective design; prospective data are necessary to identify patients who may benefit from combination chemo-immunotherapy.

Radiographic progression-free survival (rPFS) and time to radiographic progression (TTrP) as surrogate endpoints in docetaxel-naïve metastatic castrate resistant prostate cancer (mCRPC): A pooled analysis of COU-AA-302 and ACIS

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Background: rPFS is often used as an intermediate clinical endpoint (ICE) for overall survival (OS) in randomized trials in mCRPC. However, the current literature shows conflicting results on the surrogacy of rPFS for OS. Moreover, it remains unknown if TTrP, which does not consider death as an event, is an ICE for OS. We performed a combined analysis of COU-AA-302 and ACIS to determine if TTrP and rPFS can be used as ICE. Methods: In COU trial, docetaxel-naïve mCRPC patients were randomized to abiraterone (abi) versus placebo. In ACIS, a similar patient population was randomized to abi alone or abi with apalutamide (abi+apa). We applied weighted Cox regression models to evaluate the effect of treatment on TTrP and OS and used landmark analyses to determine the if the treatment effect on OS is mediated by that on radiographic progression. We estimated a semiparametric Spearman correlation between the ICE and OS at the patient level. We determined the trial level correlation of treatment effect on the ICE and OS in the 2 trials where each of them was subdivided into 9 pseudo-trial centers and then calculating the adjusted R2 between center level estimates of treatment effect for ICE and OS. The procedure of creating pseudo-trial centers was repeated 500 times and the presented R2 is the average across 500 repetitions after excluding those with negative association. Results: Overall, 2016 patients were eligible for this study – 1053 from COU and 963 from ACIS. Abi was associated with superior TTrP (HR 0.55 [95%CI 0.45-0.66]) and OS (HR 0.80 [0.70-0.92]). Similar results were seen with abi+apa (0.51 [0.41-0.64], 0.77 [0.65-0.91]). Radiographic progression was associated with significantly higher hazard of death in the state arrival extended Markov proportional hazard model (3.64 [1.54-8.62]) while longer TTrP was associated with reduced hazard of death (0.94 [0.93-0.95]). At the patient level, the correlation between TTrP & OS and rPFS & OS was 0.58 [0.54-0.63] and 0.68 [0.65-0.71], in the overall cohort. In the abi and abi+apa group, the correlation between TTrP and OS was 0.60 [0.53-0.66] and 0.73 [0.66-0.79] and that for rPFS and OS was 0.72 [0.67-0.75] and 0.79 [0.74-0.83], respectively. At the trial level, the treatment effect on rPFS & OS and TTrP & OS were correlated with average R2 of 0.84, 0.84, 0.85, and 0.86, respectively. The mean surrogate threshold effect over 500 permutations for HRrPFS and HRTTrP was 0.78 and 0.70 in ACIS and 0.54 and 0.45 in the COU-AA-302 trials, respectively. Conclusions: TTrP and rPFS were found to have significant association with OS in chemo-naïve mCRPC patients. We noted a modest to strong correlation between the treatment effect on both the ICE and OS at the trial level. Larger meta-analytic studies are needed to validate these findings.

Adjuvant immunotherapy in renal cell carcinoma: A systematic review and meta-analysis of randomized clinical trials

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Background: There has been interest in adjuvant immune checkpoint inhibition (ICI) following surgical resection in patients with high-risk renal cell carcinoma (RCC) given high recurrence rates and approvals of ICI in metastatic RCC. The primary objective of this analysis was to synthesize available data regarding the disease-free survival (DFS) benefit of adjuvant ICIs for patients with RCC. Methods: This systematic review was performed according to the PRISMA guidelines. The protocol was registered in PROSPERO (CRD42022361599). We searched PubMed, EMBASE, and relevant conference proceedings to identify phase III randomized controlled trials (RCTs) comparing adjuvant ICI versus placebo/observation. The primary outcome of interest was DFS. Results: Among the four included studies, one demonstrated a significant DFS benefit. There was considerable clinical and statistical heterogeneity (I2=64%) due to differences in inclusion criteria and interventions. While pooled results across the four studies did not demonstrate a significant benefit in DFS overall (HR 0.85, 95% CI 0.69-1.04), there was significant benefit among patients with positive PD-L1 expression (HR 0.72, 95% CI 0.55-0.94) or sarcomatoid features (HR 0.59, 95% CI 0.38-0.91). Conclusions: The evidence base to date regarding ICI as adjuvant therapy in RCC is mixed – conclusions are limited by considerable heterogeneity between studies. However, pooled analyses suggest that patients with positive PDL1 expression or sarcomatoid features are most likely to benefit from adjuvant immunotherapy.

Comparative real-world survival outcomes of muscle-invasive bladder cancer treated with bladder-only vs. whole-pelvis concurrent chemoradiation

488

Background: Elective nodal irradiation for patients with muscle-invasive bladder cancer (MIBC) undergoing trimodal therapy (TMT) is controversial. In patients with node-negative (N0) MIBC, the benefit of elective whole-pelvis concurrent chemoradiotherapy (WP-CCRT) compared to bladder-only (BO)-CCRT has not been demonstrated. Currently, the National Comprehensive Cancer Network (NCCN) guidelines do not recommend whether to include pelvic nodes in the radiation field. Using real-world data from the National Cancer Database (NCDB), we sought to compare the overall survival (OS) between BO-CCRT and WP-CCRT for MIBC. Methods: Using the 2019 NCDB Participant User File, we identified cases of MIBC diagnosed between 2017 and 2018. We selected patients with clinical T2-T4N0M0 disease receiving TMT as first-line treatment. TMT was defined as transurethral resection of bladder tumor followed by CCRT: 60–65 Gy of RT delivered to the bladder with concurrent single- or multiple-agent chemotherapy. Patients were stratified into BO-CCRT vs. WP-CCRT. Overall survival (OS) analysis was performed using Kaplan-Meier estimates and multivariable Cox proportional hazards regression analysis. The variables included in the multivariable Cox regression model were age, sex, race, comorbidity burden (as per the Charlson-Deyo comorbidity index), facility type, insurance status, median income quartile, rurality, distance from facility, and clinical T stage. Results: A total of 605 patients receiving TMT for MIBC were identified: 162 (26.8%) BO-CCRT and 443 (73.2%) WP-CCRT. The median follow-up time was 25.6 months (interquartile range [IQR]: 4.8-42.6) and 28.7 months (IQR: 3.0-51.6) for BO-CCRT and WP-CCRT, respectively. The median OS was 32.9 months (95% confidence interval [CI] 30.8 – not reached) and 48.3 months (95% CI 39.6 – not reached) for BO-CCRT and WP-CCRT, respectively. However, multivariable Cox regression analysis failed to find an association between WP-CCRT (hazard ratio [HR] 1.08, 95% CI 0.76-1.54) and improved OS, compared to BO-CCRT. Conclusions: Elective nodal-irradiation (WP-CCRT) in the setting of TMT for MIBC was not associated with a benefit in OS compared to BO-CCRT.

Practice patterns and predictors of treatment intensification in patients with metastatic castration-sensitive prostate cancer

76

Background: In recent years, treatment intensification beyond androgen deprivation therapy (ADT) with several novel therapies have shown survival benefit in patients with metastatic castration-sensitive prostate cancer (mCSPC). Given the rapidly evolving landscape in mCSPC treatment, there is a need to better understand how treatment strategies fit in real-world clinical practice and are combined/sequenced with other available therapies. Methods: Using electronic medical records and administrative data, a population-based retrospective cohort study was conducted. Patients aged ≥18 years of age who were newly diagnosed with de novo mCSPC and initiated ADT post-diagnosis between 2010 to 2020 in Alberta, Canada, were included. Treatment intensification was defined as the receipt of apalutamide, abiraterone acetate, enzalutamide, or chemotherapy (e.g. docetaxel) within 180 days of ADT initiation. Results: A total of 2,515 de novo mCSPC were identified during study period with 2,098 (83%) patients initiating ADT post-diagnosis. Of those, 525 (25%) received intensification beyond ADT. The percentage of patients who were intensified was 3% in 2010-2013 and gradually increased to 67% in 2020. Between 2014-2017, docetaxel was the most common therapy for intensification, but its use decreased considerably in 2018-2020 with abiraterone acetate, apalutamide and enzalutamide becoming increasingly available in the mCSPC setting. Upon progression, 46% and 22% in the intensified group versus 38% and 13% in the ADT-alone group initiated one and two-lines of subsequent therapies respectively. Abiraterone acetate and enzalutamide were the most common subsequent therapy for both the intensified (32% and 31% respectively) and the ADT-alone (56% and 38% respectively) groups. Docetaxel (24%) was used as subsequent therapy among mCSPC patients who were intensified with oral systemic agents. In multivariable logistic regression analyses of patients diagnosed in 2014-2020, significant predictors of intensification were younger age at diagnosis, lower Charlson comorbidity index, greater number of metastatic sites, shorter time to ADT initiation, referral to a specialists/cancer centres, surgery or radiation prior to ADT, and more recent year of diagnosis (all p<0.05). Conclusions: In Alberta, Canada, there has been a considerable increase in the utilization of ADT intensification therapies that correspond with the timing of clinical trial data and approvals of novel agents. Early referral to specialists/cancer centres is warranted to intensify mCSPC treatment beyond ADT and to improve patients’ outcomes. [Table: see text]

Assessment of the epidemiological trends for prostate cancer using administrative data in Ontario

Introduction: Studies have shown fluctuations in prostate cancer (PCa) incidence and prevalence over time and by region. Less is known about the most recent epidemiological trends by PCa disease stage. Methods: This study was a population-based, sequential, cross-sectional analysis that used administrative health data from Ontario, Canada. After inclusion, patients were classified into major PCa disease states: non-metastatic PCa and metastatic PCa. The primary study outcome was a description of temporal trends in the incidence and prevalence of PCa over the study period (2010–2019), stratified by disease state. Crude incidence and prevalence rates were estimated for each year in the study period. Results: Overall, there were 131 718 men living with PCa in 2019. The incident cohort contained 86 123 patients with nmPCa (n=65 691, 76.3%), mPCa (n=8431, 9.8%), or unknown stage (n=12 001, 13.9%). The prevalence has increased from 216 to 253 per 10 000 men, between 2010 and 2019, respectively. Between 2011 and 2014, overall PCa incidence decreased from 20.9 to 15.4 per 10 000 men, followed by an increase to 18.8 per 10 000 in 2018. The nmPCa incidence rate was considerably higher compared with mPCa and followed a trend similar to the overall incidence. In contrast, the incidence rate for mPCa demonstrated a continuous increase from 1.5 per 10 000 in 2010 to 2.4 per 10 000 in 2018. Conclusions: The overall prevalence of PCa has steadily risen over the last decade, despite fluctuations in nmPCa incidence. The concurrent rise in mPCa and nmPCa requires further study regarding the burden of localized and systemic treatment.

Patient-reported Outcomes After External Beam Radiotherapy With Low Dose Rate Brachytherapy Boost vs Radical Prostatectomy for Localized Prostate Cancer: Five-year Results From a Prospective Comparative Effectiveness Study

PURPOSE

Data comparing radical prostatectomy and external beam radiation therapy with low dose rate brachytherapy boost are lacking. To better guide shared decision making regarding treatment, we compared patient reported outcomes through 5 years following radical prostatectomy or external beam radiation therapy with low dose rate brachytherapy boost for localized prostate cancer.

MATERIALS AND METHODS

From 2011-2012, men aged <80 years with localized prostate adenocarcinoma were enrolled and followed longitudinally. Patient reported outcomes included the Expanded Prostate Index Composite. Regression models adjusted for baseline scores and covariates were constructed.

RESULTS

The study population included 112 men treated with external beam radiation therapy with low dose rate brachytherapy boost and 1,553 treated with radical prostatectomy. Compared to radical prostatectomy, external beam radiation therapy with low dose rate brachytherapy boost was associated with clinically meaningful worse urinary irritative/obstructive (adjusted mean score difference [95% confidence interval]: 5.0 [-8.7, -1.3]; P = .008 at 5 years) and better urinary incontinence function (13.3 [7.7, 18.9]; P < .001 at 5 years) through 5 years. Urinary function bother was similar between groups (P > .4 at all timepoints). Treatment with external beam radiation therapy with low dose rate brachytherapy boost was associated with worse bowel function (-4.0 [-6.9, -1.1]; P = .006 at 5 years) through 5 years compared to radical prostatectomy. Treatment with external beam radiation therapy with low dose rate brachytherapy boost was associated with better sexual function at 1 year (12.0 [6.5, 17.5]; P < .001 at 1 year) compared to radical prostatectomy, but there was insufficient evidence to reject the supposition that no difference was seen at 3 or 5 years.

CONCLUSIONS

Compared to radical prostatectomy, external beam radiation therapy with low dose rate brachytherapy boost was associated with clinically meaningful worse urinary irritative/obstructive and bowel functions but better urinary incontinence function through 5 years after treatment. These patient-reported functional outcomes may clarify treatment expectations and help inform treatment choices for localized prostate cancer.

Progression patterns by types of metastatic spread, prostate-specific antigen (PSA), and clinical symptoms: Post-hoc analyses of ARAMIS

5044

Background: Darolutamide (DARO), a highly potent and structurally distinct androgen receptor inhibitor, prolonged metastasis-free survival by nearly 2 years and reduced the risk of death by 31% vs placebo (PBO) with a favorable tolerability profile in patients (pts) with nonmetastatic castration-resistant prostate cancer (nmCRPC) in ARAMIS. We present post-hoc analyses of ARAMIS to evaluate the association between metastatic progression with prostate-specific antigen (PSA) and clinical progression and to describe the distribution of metastatic progression between groups. Methods: Pts with nmCRPC were randomized 2:1 to DARO (n=955) or PBO (n=554) while continuing androgen-deprivation therapy. Descriptive analyses were performed using the primary data cutoff (Sept 3, 2018) for the double-blind period. Post-baseline metastases were based on central review of conventional radiographic imaging every 16 weeks. PSA and pain progression were defined per primary analysis ( N Engl J Med. 2019;380:1235-46). Results: Metastatic progression was observed in 13.6% of DARO and 28.5% of PBO pts. Most pts had isolated progression as bone (DARO 46%, PBO 39%) or lymph node (32%; 40%) metastasis (Table). Pts with radiographic progression had shorter median time from initial diagnosis to study treatment (DARO 72.9, PBO 74.4 months) vs the overall ARAMIS population (86.2, 84.2 months). Of all pts with metastatic progression, baseline PSA levels (ng/mL) were similar in DARO (12.6) and PBO pts (15.1); DARO pts had lower median PSA before metastasis (16.7) vs PBO pts (48.0) and median absolute/relative PSA decrease from baseline of -0.7/-3.2% vs an increase for PBO pts of 29.5/181%. PSA progression before metastasis was observed in 55.6% (160/288) of pts, occurring in fewer DARO (45.4%) vs PBO pts (63.9%) (treatment difference 18.5%; nominal 95% CI 6.5%–30.6%). The median time between PSA progression and metastasis was 7.0 months with DARO vs 5.6 months with PBO. Pain progression before metastatic progression was rare and similar between groups (DARO 16.9%, PBO 17.7%). Conclusions: DARO significantly reduced risk of metastatic progression and improved overall survival vs PBO without changing the pattern of metastatic progression. Many pts with nmCRPC experienced metastatic progression without PSA progression, and pain progression was rare. These results support the use of imaging with PSA monitoring to properly identify disease progression in pts with nmCRPC. Clinical trial information: TBC. [Table: see text]

Patterns of care for patients with non-metastatic castration-resistant prostate cancer: Population-based study in Ontario, Canada

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Background: To describe patterns of practice of PSA testing and imaging for Ontario men receiving continuous androgen deprivation therapy (ADT) for the treatment of non-metastatic castration-resistant prostate cancer (nmCRPC). Methods: This was a retrospective, longitudinal, population-based study of administrative health data from 2008 to 2019. Men > 65 years old receiving continuous ADT with documented CRPC were included. An administrative proxy definition was applied to capture patients with nmCRPC patients and excluded those with metastatic disease. Patients were indexed upon progression to CRPC and were followed until death or end of study period to assess frequency of monitoring with PSA tests and conventional imaging. A 2-year look-back window was used to assess patterns of care leading up to CRPC, as well as baseline covariates. Results: At a median follow-up of 40 months, 944 patients with CRPC were identified. Their median time from initiation of ADT to CRPC was 26 months, 61% of patients had their PSA measured twice or fewer in the year prior to index and 71% patients did not receive any imaging in the year following progression to CRPC. Almost all patients (98%, n = 921/944) in the study progressed to high-risk CRPC (HR-CRPC) during the study period, of which more than half received fewer than 3 PSA tests in the year prior to progression to HR-CRPC, and 31% received no imaging in the subsequent year. Conclusions: PSA testing and imaging studies are under-utilized in a real-world setting for the management of nmCRPC, including those at high-risk of developing metastatic disease. Infrequent monitoring impedes proper risk stratification, disease staging, detection of treatment failure and/or metastases, likely delaying necessary treatment intensification with life-prolonging therapies. Adherence to guideline recommendations and the importance of timely staging should be reinforced to optimize patients’ outcome.

Association between pelvic nodal radiotherapy and patient-reported functional outcomes through 5 years among men undergoing external-beam radiotherapy for prostate cancer: An assessment of the comparative effectiveness analysis of surgery and radiation (CEASAR) cohort

BACKGROUND

The role of pelvic irradiation in men receiving external beam radiotherapy (EBRT) for prostate cancer is unclear, in part due to a lack of data on patient-reported outcomes. We sought to compare functional outcomes for men receiving prostate and pelvic versus prostate-only radiotherapy, longitudinally over 5 years.

MATERIALS AND METHODS

We performed a population-based, prospective cohort study of men with clinically-localized prostate cancer undergoing EBRT. We examined the effect of prostate and pelvic (n = 102) versus prostate-only (n = 485) radiotherapy on patient-reported disease-specific (using the Expanded Prostate Cancer Index Composite[EPIC]-26) and general health-related (using the SF-36) function, over 5 years. Regression models were adjusted for outcome-specific baseline function, clinicopathologic characteristics, and androgen deprivation therapy (ADT).

RESULTS

587 men (median [quartiles] age 69 [64-73] years) met inclusion criteria and completed ≥1 post-treatment survey. More men treated with prostate and pelvic radiotherapy had high-risk disease (58% vs. 18%, P < 0.01) and received ADT (75% vs. 41%, P < 0.01). These men reported worse sexual (6 months-5 years), hormonal (at 6 months), and physical (6 months-5 years) function. Accounting for baseline function, patient and tumor characteristics, and use of ADT, pelvic irradiation was not associated with statistically or clinically significant differences in bowel function, urinary incontinence, irritative voiding symptoms or sexual function through 5-years (all P > 0.05). Marginally clinically important differences were noted in hormonal function at 3-years (adjusted mean difference 4.7, 95% confidence interval [1.2-8.3]; minimally clinically important difference (MCID) 4 to 6) and 5-years (4.2, [0.4-8.0]) following treatment. After adjustment, there was a transient statistically significant, but not clinically important, difference in emotional well-being at 6 months (3.0, [0.19-5.8]; MCID 6) that resolved by 1 year and no differences in physical functioning or energy and fatigue.

CONCLUSION

This prospective, population-based cohort study of men with localized prostate cancer treated with EBRT, showed no clinically important differences in disease-specific or general health-related quality of life with the addition of pelvic irradiation to prostate radiotherapy, supporting the use of pelvic radiotherapy when it may be of clinical benefit, such as men with increased risk of nodal involvement.

Trends in medicare spending across strata of resource utilization among older individuals in the United States

BACKGROUND

Health care spending is an increasing proportion of government expenditures in most Western countries. How this growth is distributed between individuals with minimal compared to high health care utilization is unknown.

METHODS

We examined total and per-capita government expenditure in an observational cohort of fee-for-service U.S. Medicare enrollees aged ≥65 years from 2007 to 2018. We categorized patients into annual resource utilization strata. We examined annualized changes in adjusted spending across resource utilization strata and the distribution of spending within and across strata for a variety of health care settings.

FINDINGS

Examining 314,593,489 beneficiary-years of coverage, the top 1% of beneficiaries accounted for 14.9% of all expenditures, the top 5% for 41.5%, the top 10% for 60.0%, the top 20% for 79.1%, and the top 50% for 95.7%. Annual expenditures remained relatively stable from 2007 to 2018, with annual mean change of 0.7% (standard deviation 1.1%; median 1.1%) and mean per capita change of 0.4% (standard deviation 1·6%; median 0·3%). Changes were similar across strata with mean increases <1% in all, save for the <50th percentile strata (mean annual growth=1·9%), a significant difference (p = 0.0002). The overall distribution of expenditures across health care settings remained consistent over time, with different distributions between expenditure strata.

INTERPRETATION

In the U.S. from 2007 to 2018, Medicare spending has a Pareto distribution in which 80% of the costs are attributable to 20% of beneficiaries. Despite low overall Medicare spending growth from 2007 to 2018, growth has been greatest among those in the lowest spending group.

FUNDING

The Commonwealth Fund (20,202,411).

Prognostic association between common laboratory tests and overall survival in men with de novo metastatic castration-sensitive prostate cancer: A population-based study

149

Background: Despite significant advancements in the treatment of metastatic prostate cancer, a validated prognostic tool for patients with de novo metastatic castration-sensitive prostate cancer (mCSPC) is still lacking. Using population-based data from Ontario, Canada, we sought to examine the prognostic association between common laboratory tests and survival for patients with mCSPC. Methods: A population-based cohort of men aged 66 years and older diagnosed with de novo metastatic prostate cancer between 2014-2019 were included. We assessed the association between laboratory tests at the time of cancer diagnosis and overall survival (OS). Utilizing a complete case analysis, we used Cox proportional hazards models to assess the association between these laboratory tests and OS while adjusting for patient and disease characteristics. Results: A total of 3,556 men with de novo mCSPC were included. On multivariable analysis, there were significant associations between OS and neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, albumin, hemoglobin, PSA decrease and PSA nadir <0.1 ng/mL (please see table). Conclusions: Commonly available laboratory tests provide important prognostic information for patients with newly diagnosed mCSPC given demonstrated associations to overall survival. Apart from PSA kinetics, none of these baseline tests were performed in more than 57% of patients indicating underutilization of these low-cost prognostic biomarkers. [Table: see text]

Geographic variation in systemic therapy in men age 66 years and older with de novo metastatic castration-sensitive prostate cancer: A population-based study in a single payer health-system

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Background: Significant developments in the standard of care for patients with de novo metastatic castration-sensitive prostate cancer (mCSPC) have been reported over the past decade. Treatment intensification with systemic therapies in addition to androgen deprivation therapy (ADT) alone is guideline recommended for most patients. We studied the geographic variation in the use of systemic therapy for de novo mCSPC in Ontario, Canada, a single-payer health system. Methods: We performed a population-based study of men aged 66 years and older diagnosed with de novo mCSPC between 2014-2019. We linked population-based healthcare databases, as administered at the level of Local Health Integration Networks (LHINs) in Ontario, to examine treatment patterns following diagnosis of de novo mCSPC. We categorized initial mCSPC treatments as those begun within 60 days preceding and 6 months following diagnosis and examined the proportion of patients receiving LHRH alone, first generation anti-androgen (AA) alone, combined androgen blockade (CAB; LHRH + 1st gen AA), ADT + abiraterone acetate + prednisone (AAP), and, ADT + docetaxel (D). In aggregate, we considered LHRH alone, AA alone and CAB as “standard ADT”, and ADT + AAP and ADT + D as “ADT-plus”. Multinomial logistic regression analyses were used to examine the association between receiving systemic treatment intensification (“ADT-plus”) or no prostate cancer pharmacotherapy relative to ADT across geographic regions, while adjusting for baseline patient and disease characteristics. Results: We identified 3,556 men over 66 with de novo mCSPC. Overall, 2794 (78.6%) received standard ADT, 311 (8.7%) did not receive prostate cancer-directed pharmacotherapy, and 451 patients (12.7%) of patients received “ADT-plus”. Utilization of AAP increased from 0.5% to 3% following the LATITUDE data release in 2017, while D decreased from 12% to 10%. There was significant variation in treatment strategies between geographic regions in use of “ADT-plus” ranging from 7 to 20% (p < 0.0001), a difference which persisted after accounting for patient demographics, comorbidity, rurality, and disease characteristics (p = 0.036). Conclusions: Despite proven survival benefits in randomized controlled trials, intensified treatment with docetaxel or abiraterone in addition to ADT was infrequently utilized in this population-based study of men age 66 years and over with mCSPC.

Real-world utilization of docetaxel among men with de novo metastatic castration-sensitive prostate cancer: A population-based study in men aged 66 or older

47

Background: Docetaxel was the first agent, when added to androgen deprivation therapy (ADT), to demonstrate a survival benefit in men with metastatic castration-sensitive prostate cancer (mCSPC). It remains an important guideline recommendation approach in these men. However, real-world experience among patients with de novo metastatic disease is poorly understood. Using population-based data from Ontario Canada, we examined the real-world experience of using docetaxel in mCSPC. Methods: Men aged 66 years and older diagnosed with de novo metastatic prostate cancer between 2014-2019 were captured. The Cancer Activity Level Reporting system tracks information regarding the use of cancer treatments, including details of systemic therapy. We identified patients who received docetaxel intensification to ADT following diagnosis of de novo mCSPC and analyzed the proportion of patients who completed 6 cycles of treatment, required a dose decrease, and who visited the emergency department (ED) or were hospitalized for febrile neutropenia. Results: Over the 5-year study period, 399 men received docetaxel treatment among 3,556 identified with de novo mCSPC. The median age was 72 (IQR 68-76) and mean Charlson comorbidity index was 0.15 (SD +/- 0.72). Of the 399 men, 230 (58%), 202 (51%) and 175 (44%) patients completed at least 4, 5 and 6 cycles of docetaxel, respectively. Dose reduction during docetaxel treatment was required in 173 (43%) patients. Filgrastim was prescribed among 29 (7.3%) patients. Hospitalization or ED visit for febrile neutropenia was observed in 63 (16 %) of patients who received docetaxel. Conclusions: Among men age 66 years and over who received docetaxel and ADT for mCSPC, less than half were able to complete all six prescribed cycles. In addition, over two fifth required dose reductions and 16% experienced febrile neutropenia requiring hospitalization or ED visit. These data highlight the differences in expected outcomes between clinical trial populations (as reported in CHAARTED) and routine use.

Re-operation within 30 days of radical cystectomy: Identifying high-risk patients and complications using American College of Surgeons National Surgical Quality Improvement Program database

INTRODUCTION

Radical cystectomy (RC) is a highly morbid procedure, with 30-day complication rates approaching 31%. Our objective was to determine risk factors for re-operation within 30 days following a RC for non-metastatic bladder cancer.

METHODS

We included all patients who underwent a RC for non-metastatic bladder cancer using The American College of Surgeons National Surgical Quality Improvement Program database between January 1, 2007 and December 31, 2014. Logistic regression analyses were used to evaluate predictors of re-operation.

RESULTS

A total of 2608 patients were included; 5.8% of patients underwent re-operation within 30 days. On multivariable analysis, increasing body mass index (BMI) (odds ratio [OR] 1.04, 95% confidence interval [CI] 1.01-1.07), African American race (vs. Caucasian OR 2.29, 95% CI 1.21-4.34), and history of chronic obstructive pulmonary disease (COPD) (OR 2.33, 95% CI 1.45-3.74) were significant predictors of re-operation within 30 days of RC. Urinary diversion type (ileal conduit vs. continent) and history of chemotherapy or radiotherapy within 30 days prior to RC were not. Patients who underwent re-operation within this timeframe had a significantly higher mortality rate (4.0% vs. 1.6%) and were more likely to experience cardiac (7.2% vs. 1.9%), pulmonary (23.0% vs. 3.0%), neurological (2.0% vs. 0.49%), and venous thromboembolic events (10.5% vs. 5.4%), as well as infectious complications (64.5% vs. 24.1%), with a significantly longer hospital length of stay (16.5 vs. 7.0 days).

CONCLUSIONS

Recognizing increasing BMI, COPD, and African American race as risk factors for re-operation within 30 days of RC will allow urologists to preoperatively identify such high-risk patients and prompt them to adopt more aggressive approaches to minimize postoperative surgical complications.

Outcomes of minimally invasive partial nephrectomy among very elderly patients: report from the RESURGE collaborative international database

The aim of the study was to perform a comprehensive investigation of clinical outcomes of robot-assisted partial nephrectomy (RAPN) or laparoscopic partial nephrectomy (LPN) in elderly patients presenting with a renal mass. The REnal SURGery in Elderly (RESURGE) collaborative database was queried to identify patients aged 75 or older diagnosed with cT1-2 renal mass and treated with RAPN or LPN. Study outcomes were: overall complications (OC); warm ischemia time (WIT) and 6-month estimated glomerular filtration rate (eGFR); positive surgical margins (PSM), disease recurrence (REC), cancer-specific mortality (CSM) and other-cause mortality (OCM). Descriptive statistics, Kaplan-Meier, smoothed Poisson plots and logistic and linear regression models (MVA) were used. Overall, 216 patients were included in this analysis. OC rate was 34%, most of them being of low Clavien grade. Median WIT was 17 minutes and median 6-month eGFR was 54 ml/min/1.73 m2. PSM rate was 5%. After a median follow-up of 20 months, the 5-year rates of REC, CSM and OCM were 4, 4 and 5%, respectively. At MVA predicting perioperative morbidity, RAPN relative to LPN (odds ratio [OR] 0.33; p <0.0001) was associated with lower OC rate. At MVA predicting functional outcomes, RAPN relative to LPN was associated with shorter WIT (estimate [EST] -4.09; p <0.0001), and with higher 6-month eGFR (EST 6.03; p = 0.01). In appropriately selected patients with small renal masses, minimally-invasive PN is associated with acceptable perioperative outcomes. The use of a robotic approach over a standard laparoscopic approach can be advantageous with respect to clinically relevant outcomes, and it should be preferred when available.

Comparative efficacy of chemoimmunotherapy versus immunotherapy alone in the front-line treatment of advanced non-small cell lung cancer: A systematic review and network meta-analysis

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Background: Immune checkpoint inhibitors (ICI) and combination chemotherapy (chemo) plus ICI (Chemo-ICI) have been shown in RCTs to have improved OS compared to chemo in the 1L treatment of advanced NSCLC. However, the benefit of chemo-ICI compared with ICI alone is unknown. Methods: Systematic review using MEDLINE, Embase and Cochrane CENTRAL was done to identify relevant studies up to December 2019. Phase 3 RCTs that evaluated the efficacy of 1L ICI or chemo-ICI and reported outcomes stratified by PD-L1 status (<1%, 1-49%, ≥50%) were included. ICI was defined as single-agent PD-1 axis inhibitor or dual checkpoint blockade with PD-1 axis inhibitor plus CTLA-4 inhibitor. Comparison for PD-L1<1% included chemo-ICI vs ipi/nivo and for PD-L1 1-49% and PD-L1>50% included chemo-ICI vs ipi/nivo or single-agent ICI. OS, PFS, and ORR were extracted. Network meta-analysis (NMA) was done in Bayesian random-effects regression models. Results: Ten phase 3 RCTs (7971 screened) involving 7,218 patients assigned to ICI (pembro or atezo or ipi/nivo) or chemo-ICI (platinum-doublet + atezo, pembro, or nivo) were included. In PD-L1 <1% patients, NMA comparing chemo-ICI with ipi/nivo failed to show a statistically significant difference in OS, PFS or ORR. In PD-L1 1-49% patients, there was no significant difference between chemo-ICI vs ICI in OS or ORR; PFS could not be analyzed due to lack of available data. In PD-L1 >50% patients, chemo-ICI was associated with improved PFS and ORR compared to ICI alone, but without any OS difference (Table). Conclusions: Although the addition of chemo to ICI appears to improve ORR and PFS in PD-L1 ≥50% patients when compared to ICI alone, chemo-ICI does not confer an OS benefit in the 1L treatment of NSCLC patients regardless of PD-L1 status. Prospective trials comparing chemo-ICI, ICI monotherapy, and combination ICI are needed to confirm these findings. OS, PFS and ORR with chemo-ICI vs ICI. [Table: see text]

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

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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.

Novel androgen receptor inhibitors in nonmetastatic castration-resistant prostate cancer: A network meta-analysis

131

Background: Novel non-steroidal anti-androgens (NSAAs) including enzalutamide, apalutamide, and darolutamide with androgen deprivation therapy (ADT) have proven efficacy in men with high-risk non-metastatic castrate resistant prostate cancer (nmCRPC). However, in the absence of direct comparative trials, there is little evidence to guide therapeutic choice. Our objective was to perform a network meta-analysis to compare agents and perform a class-level meta-analysis of NSAAs with androgen deprivation therapy (ADT) versus ADT-alone. Methods: We performed a systematic review of phase III parallel-group RCTs in men ≥18 years of age with nmCRPC using EMBASE and MEDLINE, indexed as of March 8, 2019. Our primary outcome was metastasis free survival (MFS). Secondary outcomes included OS, PSA progression free survival (PFS), and rates of grade 3-4 adverse events (AEs). Three RCTs were identified. We performed a random effects meta-analysis of NSAA versus ADT-alone using the inverse variance technique for meta-analysis for efficacy outcomes and the Mantel-Haenszel method for meta-analysis of dichotomous data for AEs. We then performed a network meta-analysis to compare outcomes between NSAAs using fixed-effect models in a Bayesian framework. We estimated the relative ranking of the different treatments for each outcome. Results: Pooled MFS, PSA-PFS, and OS were significantly greater with NSAA versus placebo (HR:0.32,95%CI:0.25-0.41, HR:0.08,95%CI:0.05-0.13, and HR:0.74,95%CI:0.61-0.90, respectively). Apalutamide and enzalutamide had a 56% and 44% likelihood of maximizing MFS, respectively. There was a 44%, 41%, and 15% likelihood that apalutamide, darolutamide and enzalutamide offered the greatest OS benefit, respectively. There was a 61% chance that darolutamide was preferred with respect to AEs. Conclusions: NSAAs improve survival outcomes in patients with high-risk nmCRPC. Apalutamide and enzalutamide may offer improved oncological outcomes. Darolutamide may result in fewer adverse events. These differences, if confirmed, would be meaningful to patients and practitioners when selecting treatment.

IMPACT of putative chemopreventative agents on prostate cancer diagnosis

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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.

Cancer diagnosis and risk of suicide after accounting for prediagnosis psychiatric care: A matched‐cohort study of patients with incident solid‐organ malignancies

BACKGROUND

Previous studies have demonstrated an association between a diagnosis of cancer and the risk of suicide; however, they failed to account for psychiatric care before a cancer diagnosis, which may confound this relationship. The objective of this study was to assess the effect of a cancer diagnosis on the risk of suicide, accounting for prediagnosis psychiatric care utilization.

METHODS

All adult residents of Ontario, Canada who were diagnosed with cancer (1 of prostate, breast, colorectal, melanoma, lung, bladder, endometrial, thyroid, kidney, or oral cancer) between 1997 and 2014 were identified. Noncancer controls were matched 4:1 based on sociodemographics, including a psychiatric utilization gradient (PUG) score (with 0 indicating none; 1, outpatient; 2, emergency department; and 3, hospital admission). A marginal, cause-specific hazard model was used to assess the effect of cancer on the risk of suicidal death.

RESULTS

Among 676,470 patients with cancer and 2,152,682 matched noncancer controls, there were 8.2 and 11.4 suicides per 1000 person-years of follow-up, respectively. Patients with cancer had an overall higher risk of suicidal death compared with matched patients without cancer (hazard ratio, 1.34; 95% CI, 1.22-1.48). This effect was pronounced in the first 50 months after cancer diagnosis (hazard ratio, 1.60; 95% CI, 1.42-1.81); patients with cancer did not demonstrate an increased risk thereafter. Among individuals with a PUG score 0 or 1, those with cancer were significantly more likely to die of suicide compared with controls. There was no difference in suicide risk between patients with cancer and controls for those who had a PUG score of 2 or 3.

CONCLUSIONS

A cancer diagnosis is associated with increased risk of death from suicide compared with the general population even after accounting for precancer diagnosis psychiatric care utilization. The specific factors underlying the observed associations remain to be elucidated.

MicroRNA-652 induces NED in LNCaP and EMT in PC3 prostate cancer cells

MicroRNAs (miRNAs) are small noncoding RNA molecules that post-transcriptionally regulate gene expression. Dysregulation of miRNAs is frequently associated with disease and, in particular, is involved in prostate cancer progression. Next generation miRNA sequencing identified a panel of five miRNAs associated with prostate cancer recurrence and metastasis. High expression of one of these five miRNAs, miR-652, correlated significantly with an increased rate of prostate cancer biochemical recurrence. Overexpression of miR-652 in prostate cancer cells, PC3 and LNCaP, resulted in increased growth, migration and invasion. Prostate cancer cell xenografts overexpressing miR-652 showed increased tumorigenicity and metastases. We found that miR-652 directly targets the B" regulatory subunit, PPP2R3A, of the tumor suppressor PP2A, inducing epithelial-mesenchymal transition (EMT) in PC3 cells and neuroendocrine-like differentiation (NED) in LNCaP cells. The mesenchymal marker N-cadherin increased and epithelial marker E-cadherin decreased in PC3 cells overexpressing miR-652. In LNCaP cells and xenografted tumors, overexpression of miR-652 increased markers of NED, including chromogranin A, neuron specific enolase, and synaptophysin. MiR-652 may contribute to prostate tumor progression by promoting NED through decreased PP2A function. MiR-652 expression could serve as a biomarker for aggressive prostate cancer, as well as provide an opportunity for novel therapy in prostate cancer.

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.

Peripheral Nerve Injury during Abdominal-Pelvic Surgery: Analysis of the National Surgical Quality Improvement Program Database

Peripheral nerve injury (PNI) is a rare but preventable complication of surgery. We sought to assess whether the use of minimally invasive surgery (MIS) affects the occurrence of PNI. Using the American College of Surgeons National Surgical Quality Improvement Program database, we examined rates of PNI among patients undergoing appendectomy, hysterectomy, colectomy, or radical prostatectomy between 2005 and 2012. We assessed the effect of MIS, as compared with open surgery, on PNI occurrence using logistic regression. Among 297,532 patients, of whom 175,884 (59.1%) underwent MIS, the rate of PNI was 0.03 per cent. Forty-four patients treated using MIS had PNI (0.03%) as compared with 63 who underwent open surgery (0.05%; P = 0.0002). There was a significant decrease in the proportion of surgeries resulting in PNI (P < 0.0001) over time. In univariate analysis, MIS was associated with a decreased occurrence of PNI (odds ratio 0.48, 95% confidence interval 0.33–0.71), but this became nonsignificant on multivariable analysis (odds ratio 0.71, 95% confidence interval 0.47–1.09). Increased operative time and smoking status were the only factors independently associated with an increased risk of PNI on multivariable analysis. MIS techniques during common abdominal-pelvic surgeries do not appear to increase the risk of PNI. Prolonged operative time and smoking are independently associated with an increased risk of PNI. Quality improvement initiatives to increase awareness of PNI and identify patients at increased risk of this preventable complication should be considered.

Population-based analysis of treatment toxicity among men with castration-resistant prostate cancer

252

Background: There is little phase 4 data regarding the toxicity and effectiveness of contemporary metastatic castrate-resistant prostate cancer (mCRPC) treatments. We examined hospital admissions and emergency room (ER) visits and survival among patients in the Province of Ontario treated with abiraterone, enzalutamide, docetaxel, or cabazitaxel for mCRPC. Methods: We performed a population-based, retrospective cohort study of 2439 men over the age of 65 treated with abiraterone, enzalutamide, docetaxel, or cabazitaxel for mCRPC from 2003-2015 in Ontario, Canada. Outcomes were toxicity (hospitalizations and ER visits) and overall survival. We used multivariable Cox proportional hazards models with time-varying exposures to calculate hazard ratios (HR). Results: Among 2439 patients, cumulative exposure was greatest for docetaxel (n = 1886 (77.3%); 11,436 person-months), followed by abiraterone (n = 893 (36.6%); 5143 person-months), enzalutamide (n = 52 (2.1%); 351 person-months) and cabazitaxel (n = 18 (0.7%); 61 person-months). Abiraterone exposure was not significantly associated with any-cause (HR 0.88, 95% CI 0.72-1.07) or treatment-related (HR 1.09, 95% CI 0.87-1.37) hospitalizations or ER visits. Enzalutamide was not significantly associated with any-cause (HR 1.20, 95% CI 0.69-2.07) or treatment-related (HR 0.85, 95% CI 0.43-1.68) toxicity. Docetaxel exposure was associated with a significantly increased risk of any-cause (HR 1.29, 95% CI 1.15-1.44) and treatment-related (HR 1.52, 95% CI 1.33-1.74) toxicity. Cabazitaxel exposure was also associated with treatment-related (HR 5.94, 95% CI 1.87-18.92) but not any-cause (HR 2.37, 95% CI 0.59-9.63) toxicity. Patients who began CRPC treatment after the introduction of oral therapies had improved overall survival compared with those treated prior to their introduction (aHR 0.70, 95% CI 0.64-0.77). Conclusions: Among patients with metastatic CRPC, treatment with chemotherapy (docetaxel or cabazitaxel) is associated with an increased risk of hospitalizations and emergency room visits. We failed to show a significantly increased risk for patients treated with oral agents (abiraterone or enzalutamide).

Long-term incidence of venous thromboembolic events following cystectomy: A population-based analysis

288

Background: Cancer and immobility both contribute to the development of venous thromboembolic events (VTE), including pulmonary embolism and deep vein thrombosis. As such, patients undergoing radical cystectomy for bladder cancer are at elevated risk. We sought to assess the long-term incidence of VTE among all patients undergoing radical cystectomy in the province of Ontario. Methods: We conducted a population-based cohort study to examine the incidence of VTE, a composite of pulmonary embolism and deep vein thrombosis, among all patients treated with radical cystectomy for bladder cancer between 2002 and 2014 in Ontario, Canada. We estimated the cumulative incidence of VTE and used Fine and Grey competing risk survival analysis to assess risk factors for VTE while accounting for the risk of any cause mortality. Results: Among 3623 eligible patients, the 10 year cumulative incidence of VTE was 6.68% (Table 1). Among those who experienced VTE, the median time from surgery was 216 days (interquartile range 52-677 days; mean 527 days). However, VTE rates peaked much earlier with a mode of 20 days. Neither preoperative (HR 0.68, 95% CI 0.39-1.18) nor postoperative chemotherapy (HR 1.32, 95% CI 0.95-1.84) were significantly associated with VTE incidence. While patients with a prior history of VTE had increased risk of VTE after cystectomy (HR 5.1, 95% CI 2.2-12.0), age, gender, comorbidity score, rurality, diversion type (continent vs ileal conduit), treatment at an academic institution, or year of treatment were not significantly associated with the risk of VTE. Conclusions: Among patients undergoing cystectomy for bladder cancer, the cumulative incidence of VTE continues to rise long after the date of surgery indicating that previous studies may have underestimated these rates, but the highest rates occur at 20 days after surgery. Chemotherapy does not appear to increase the risk of VTE. [Table: see text]

Prostate Cancer Genetics: A Review

Over the past decades, research has focussed on identifying the genetic underpinnings of prostate cancer. It has been recognized that a number of forms of genetic changes coupled with epigenetic and gene expression changes can increase the prediction to develop prostate cancer. This review outlines the role of somatic copy number alterations (SCNAs), structural rearrangements, point mutations, and single nucleotide polymorphisms (SNPs) as well as miRNAs. Identifying relevant genetic changes offers the ability to develop novel biomarkers to allow early and accurate detection of prostate cancer as well as provide risk stratification of patients following their diagnosis. The concept of personalized or individualized medicine has gained significant attention. Therefore, a better understanding of the genetic and metabolic pathways underlying prostate cancer development offers the opportunity to explore new therapeutic interventions with the possibility of offering patient-specific targeted therapy.

The role of resection of pulmonary metastases from prostate cancer: a case report and literature review

We report a case of a 53-year-old man who presented with twonodules in the lower lobe and one nodule in the upper lobe of theright lung almost 7 years after radical prostatectomy for pT3aN0M0,Gleason 4+5 disease, without evidence of osseous or lymphaticspread. Surgical resection of the lower lung nodules confirmedmetastases, but prostate-specific antigen did not drop to undetectablelevels. Isolated pulmonary metastases from prostate cancerare rare with only 33 previously described cases in the Englishlanguageliterature, 18 of which were solitary metastases. Wereview the principles of management, including metastasectomyand long-term prognosis.

Effects of calcium channel blockers on pentylenetetrazol drug discrimination in rats

The effects of the dihydropyridine L-type calcium channel blockers nitrendipine and nimodipine on the pentylenetetrazol (PTZ) drug discrimination, an operant model of anxiety, were investigated. Male Long-Evans rats were trained to discriminate PTZ (16 mg/kg, i.p.) from saline. Both nitrendipine (5.0-25 mg/kg, i.p.) and nimodipine (5.0-25 mg/kg, i.p.) partially substituted for the PTZ discriminative stimulus. However, pretreatment with nitrendipine (25 mg/kg, i.p.) or nimodipine (25 mg/kg, i.p.) produced no change in the PTZ dose-effect function. Rats were given a nutritionally balanced liquid diet containing 6.5% ethanol for 10 days. Rats selected the PTZ drug lever during withdrawal. Subchronic coadministration of nitrendipine (1.25-5.0 mg/kg, i.p., b.i.d.) with ethanol failed to dose-dependently reduce PTZ-lever responding, but it did reverse withdrawal signs. Acute administration of nitrendipine (5, 10, and 20 mg/kg, i.p.) produced marked suppression of lever responding, but it failed to significantly reduce levels of PTZ-lever responding. Although calcium channel blockers reduce signs of ethanol withdrawal, they also markedly reduce rates of behavior and produce no clear effects on anxiety-like behaviors induced by ethanol withdrawal.

Abecarnil and alprazolam reverse anxiety-like behaviors induced by ethanol withdrawal

This study investigated the effects of a benzodiazepine partial agonist, abecarnil, and a full agonist, alprazolam, on ethanol withdrawal-induced anxiety-like behaviors in rats. Anxiety was assessed in two models: elevated plus maze and pentylenetetrazol (GABA(A) antagonist) discrimination assay. Male rats received an ethanol-containing (4.5%) liquid diet for 7 to 10 days and were tested for withdrawal symptoms 12 h after termination of the diet. In the elevated plus maze, ethanol-withdrawn rats displayed less open arm activity and total arm entries than pair-fed rats. Abecarnil (0.08-0.32 mg/kg, IP) and alprazolam (0.08-1.25 mg/kg, IP) each produced a dose-dependent, full reversal of ethanol withdrawal-induced reduction of open arm activity, but only alprazolam increased the total arm entries. In the pentylenetetrazol assay, ethanol-withdrawn rats selected the pentylenetetrazol lever (100%) over the salin-lever. Abecarnil (0.04-0.32 mg/kg, IP) and alprazolam (0.08-0.32 mg/kg, IP) dose dependently reduced pentylenetetrazol-lever responding to control levels (10-20%). Alprazolam was more potent than abecarnil in reversing ethanol withdrawal-induced decrease in open arm activities, but showed comparable potency and efficacy to abecarnil in blocking the pentylenetetrazol-like ethanol withdrawal stimulus. These results suggest that abecarnil and alprazolam may have therapeutic potential for treatment of ethanol withdrawal-induced anxiety-like symptoms.

Effects of ritanserin on ethanol withdrawal-induced anxiety in rats

This study investigated the ability of ritanserin, a 5-HT2 antagonist, to modify ethanol withdrawal (EW) symptoms in two animal models of anxiety: the elevated plus-maze (EPM) and the pentylenetetrazol (PTZ) discrimination assay. Long-Evans hooded rats were given a nutritionally balanced liquid diet containing 4.5% ethanol for 10 days. Twelve hours after removal of the ethanol diet, rats were tested in the EPM. A significant reduction in the open-arm activity and the number of total arm entries was observed, which is indicative of EW. Acute ritanserin (0.16-0.64 mg/kg, i.p., 60 min) had no effect on EW-induced anxiety-like behavior on the EPM. Ritanserin (0.08-0.64 mg/kg, i.p., b.i.d. 12 h) administered concurrently with the last 5 days of ethanol diet produced an increase in the time spent on the open arms of the EPM and reversed the EW-induced reduction in total arm entries. Rats trained to discriminate between saline and PTZ (an anxiogenic drug), selected the PTZ lever during EW. Chronic ritanserin (0.32 mg/kg, i.p., b.i.d. ) did not block PTZ lever responding during EW. On the rotorod, ritanserin (0.32 mg/kg, i.p.) increased the motor incoordination induced by ethanol. In conclusion, coadministration of ritanserin with ethanol prevented the development of EW-induced anxiety as measured by the EPM, but not in the PTZ drug discrimination.

Sex differences in the discriminative stimulus effects of m-chlorophenylpiperazine and ethanol withdrawal

RATIONALE

The serotonergic system plays a role in regulation of anxiety and ethanol withdrawal (EW). Nevertheless, few studies have assessed sex differences in serotonergic effects on EW.

OBJECTIVES

This study examined sex differences in the anxiogenic stimuli induced by a serotonin (5-HT)(1b,2) agonist, meta-chlorophenylpiperazine (mCPP), prior to ethanol and during EW.

METHODS

Gonadectomized or sham-operated adult male and female rats and 17beta-estradiol (2.5 mg, 21-day release, s.c.) -replaced ovariectomized (OVX) rats were trained to discriminate mCPP (1.2 mg/kg, i.p.) from saline in a two-lever choice task for food. Latency to the first lever press and mCPP lever selection were measured following mCPP (0-1.2 mg/kg). Rats then received chronic ethanol-containing liquid diet (6.5%) for 10 days and were tested for mCPP lever selection 12 h and 36 h after removal of ethanol.

RESULTS

Fewer sham female and beta-estradiol-replaced OVX rats selected the mCPP lever than male or OVX rats, and showed an increased initiation latency after mCPP injection. During EW (12 h and 36 h), fewer sham female and beta-estradiol-replaced OVX rats responded on the mCPP-lever after saline injection as well as after mCPP challenge than male or OVX rats. Castration did not alter any response of male rats to mCPP.

CONCLUSIONS

(1) mCPP discrimination is a useful measure of EW in male and female rats; and (2) sham female and beta-estradiol-replaced OVX rats are less sensitive to the discriminative stimulus prior to and during EW, but more sensitive to impaired behavioral initiation induced by mCPP than male or OVX rats.