Evaluating robotic-assisted partial nephrectomy surgeons with fully convolutional segmentation and multi-task attention networks

We use machine learning to evaluate surgical skill from videos during the tumor resection and renography steps of a robotic assisted partial nephrectomy (RAPN). This expands previous work using synthetic tissue to include actual surgeries. We investigate cascaded neural networks for predicting surgical proficiency scores (OSATS and GEARS) from RAPN videos recorded from the DaVinci system. The semantic segmentation task generates a mask and tracks the various surgical instruments. The movements from the instruments found via semantic segmentation are processed by a scoring network that regresses (predicts) GEARS and OSATS scoring for each subcategory. Overall, the model performs well for many subcategories such as force sensitivity and knowledge of instruments of GEARS and OSATS scoring, but can suffer from false positives and negatives that would not be expected of human raters. This is mainly attributed to limited training data variability and sparsity.

Toll-Like Receptor 4 Induction During Renal Ischemia Correlates with Serum Creatinine in a Pig Model

Objectives: To determine whether toll-like receptor 4 (TLR4), a mediator of organ ischemia-reperfusion injury, is overexpressed during warm ischemia in a porcine solitary kidney model, and whether its expression correlates with creatinine, a surrogate for kidney function. Materials and Methods: Eight adult Yorkshire pigs underwent initial laparoscopic nephrectomy. After 1 week, animals were randomized into two groups: group 1 underwent laparoscopic renal hilar dissection, renal ischemia by cross-clamping, and reperfusion (ischemia group); group 2 underwent laparoscopic renal hilar dissection alone (sham group). Animals were survived to day 7 postrandomization. Peripheral blood was sampled for serum creatinine (sCr) and TLR4 expression at the following time points or corresponding intervals: prenephrectomy, 1-week postnephrectomy (preischemia), after 90 minutes of ischemia, 30 minutes postreperfusion, and at sacrifice. Intragroup TLR4 expression changes were analyzed using repeated measures ANOVA. Intergroup TLR4 expression was compared using Mann-Whitney's test. Correlation between sCr and TLR4 was assessed using Spearman's test. Results: Seven animals completed the experiment (four ischemia and three sham). Relative TLR4 expression significantly increased from baseline levels during ischemia, reperfusion, and sacrifice time points only in the ischemia group, and was significantly higher for the ischemia group after 90 minutes of ischemia (p = 0.034). sCr was significantly higher for the ischemia group during the reperfusion phase (p = 0.048). Relative TLR4 expression level significantly correlated with sCr in the overall cohort (Spearman's rho = 0.69) and in the ischemia group (Spearman's rho = 0.82; p < 0.0001 for each). Conclusions: Warm ischemia in a porcine solitary kidney induces acute overexpression of TLR4 in peripheral blood leukocytes, which is detectable. Relative TLR4 expression level strongly correlated with sCr but had an observable change sooner than change in sCr. Pending further investigation, TLR4 overexpression during renal ischemia may represent a sensitive quantitative marker of unilateral renal injury sustained during nephron-sparing surgery.

Evaluating Surgical Outcomes of Robot Assisted Simple Prostatectomy in the Retreatment Setting

OBJECTIVE

To report perioperative and postoperative outcomes in men who undergo salvage RASP (sRASP) following some other endoscopic outlet procedure for benign prostate enlargement (BPE) compared to those undergoing RASP for primary treatment (pRASP).

METHODS

A prospectively maintained database consisting of all RASP surgeries (December 2014 - October 2019) performed at our institution by three different urologists was used. Patients who had received an endoscopic procedure for BPE prior to their RASP (sRASP) were compared to those who had not had a prior outlet procedure (pRASP).

RESULTS

In total, 310 men underwent RASP during the study period. Of those, 30 (9.7%) had undergone an endoscopic procedure prior to surgery. There were no significant differences in age, race, ASA, BMI, prostate volume, PSA or rates of preoperative retention (p>0.05 for all). Men who were treatment-naive had significantly higher preoperative International Prostate Symptom Scores (IPSS) than men who had a prior procedure (18.3 ±7.7 vs. 13.6 ±6.2, p=0.008). However, there were no significant differences in functional or quality of life outcomes between the two groups (p>0.05 for all). There were no significant differences in perioperative or post-operative outcomes between the two groups. Furthermore, rates of post-operative complications and incontinence were similar between groups (11% vs. 10%, p=0.9 and 2% vs. 0%, p=1 respectively).

CONCLUSION

Performing a RASP after prior endoscopic procedure for BPE was found to be safe and effective. Success and complication rates were similar to patients with no prior procedures.

Identifying predictors of antispasmodic use following robotic assisted simple prostatectomy

INTRODUCTION

Anticholinergic or ß-3 agonist use following robotic simple prostatectomy (RASP) is not well described. We describe rates of antispasmodic use following RASP and identify potential predictors of medication use.

MATERIALS AND METHODS

A retrospective review of all RASP patients from 2/2016 - 1/2020 was conducted. Patients with no preoperative International Prostate Symptom Score (IPSS) were excluded. Demographics, clinical data, and postoperative medication use were collected by electronic medical record review. Multivariable logistic regression analysis using a priori variables was performed to identify independent factors associated with antispasmodic use.

RESULTS

A total of 255 patients underwent RASP at a mean age of 70.0 years ± 7.3 and mean body mass index (BMI) of 28.6 kg/m² ± 5.0. Median preoperative prostate volume was 132.3 cc ± 45.0. Rates of preoperative diabetes, obstructive sleep apnea (OSA), smoking and alcohol use were 19.6%, 6.3%, 3.1%, and 11.8% respectively; 8.6% of patients (n = 22) initiated antispasmodics at a median of 2.5 months (IQR 1.3-4.2) postoperatively. Median duration of antispasmodic use was 6.5 months (IQR 1.7-14.7). Mirabegron was most commonly prescribed (31.8%). On multivariable logistic regression analysis, OSA was independently associated with postoperative antispasmodic use (OR 8.13, 95% CI 2.02-32.67, p = 0.003); 68.8% of OSA patients were treated with continuous positive airway pressure (CPAP). Treatment was not significantly associated with postoperative antispasmodic use (p = 0.61).

CONCLUSION

Patients with OSA are over 8 times more likely to require antispasmodic medications following RASP in the short term. These patients may benefit from more tailored preoperative counseling.

Evaluating robotic-assisted surgery training videos with multi-task convolutional neural networks

We seek to understand if an automated algorithm can replace human scoring of surgical trainees performing the urethrovesical anastomosis in radical prostatectomy with synthetic tissue. Specifically, we investigate neural networks for predicting the surgical proficiency score (GEARS score) from video clips. We evaluate videos of surgeons performing the urethral anastomosis using synthetic tissue. The algorithm tracks surgical instrument locations from video, saving the positions of key points on the instruments over time. These positional features are used to train a multi-task convolutional network to infer each sub-category of the GEARS score to determine the proficiency level of trainees. Experimental results demonstrate that the proposed method achieves good performance with scores matching manual inspection in 86.1% of all GEARS sub-categories. Furthermore, the model can detect the difference between proficiency (novice to expert) in 83.3% of videos. Evaluation of GEARS sub-categories with artificial neural networks is possible for novice and intermediate surgeons, but additional research is needed to understand if expert surgeons can be evaluated with a similar automated system.

Clinical Outcomes of Robotic Assisted Partial Nephrectomy for Pathologic T3a Renal Masses with Venous Tumor Thrombus

OBJECTIVE

To evaluate the safety, efficacy, and early oncologic outcomes of pT3a renal cell carcinoma (RCC) with venous involvement treated with robotic partial nephrectomy (RPN), given that experience and outcomes in this group is limited.

METHODS

A retrospective chart review of patients undergoing RPN from 9/2009-7/2020 was performed. Outcomes were captured from patients with pathologic T3a disease with vein involvement. Clinical characteristics were analyzed using SPSS (IBM, Armonk, NY). Local recurrence-free survival (LRFS) and metastasis-free survival (MFS) at 2 years were calculated from Kaplan-Meier survival curves.

RESULTS

For 45 included patients, mean operative and warm ischemia times were 199.6 min ± 47.3 and 30.5 min ± 10.5, with mean estimated blood loss of 324.9 cc ±209.5. Rates of transfusion, embolization, re-admission, and re-operation at 30 days were 8.9% (4/45), 2.2% (1/45), 11.1% (5/45), and 6.7% (3/45; cystoscopic stent placement), respectively. All tumors were malignant on pathology, with clear cell RCC being the most common (91.0%, n=41). The positive margin rate was 6.7% (n=3). Local recurrence occurred in 4.4% (n=2) at a mean time of 5.2 months ± 2.3. Four patients (8.9%) progressed to metastatic disease at a mean of 22.2 months ± 23.0. At 2 years, LRFS was 95.4% and MFS was 95.3%.

CONCLUSIONS

We present the largest known series of patients RPN for pT3a renal masses with venous tumor involvement. We found it both feasible and safe in the appropriate hands. Short term oncologic outcomes for these patients appear more favorable than historic literature suggested. SOURCES OF FUNDING: none.

Irreversible Electroporation for the Treatment of Small Renal Masses: 5-Year Outcomes

Introduction: Irreversible electroporation (IRE) is a nonthermal ablative technology that applies high-voltage short-pulse electrical current to create cellular membrane nanopores and ultimately results in apoptosis. This is thought to overcome thermal limitations of other ablative technologies. We report 5-year oncologic outcomes of percutaneous IRE for small renal masses. Patients and Methods: A single-institution retrospective review of cT1a renal masses treated with IRE from April 2013 to December 2019 was performed. Those with <1 month follow-up were excluded. IRE was performed with the NanoKnife^© System (Angiodynamics, Latham, NY). Renal mass biopsy was obtained before or during ablation in most circumstances; biopsy was excluded in some patients because of concern for IRE probe displacement. Postablation guideline-based surveillance imaging was performed. Initial treatment failure was defined as persistent tumor enhancement on first post-treatment imaging. Survival analysis was performed through the Kaplan-Meier method for effectively treated tumors (SPSS; IBM, Armonk, NY). Results: IRE was used to treat 48 tumors in 47 patients. Twenty-two per 48 tumors (45.8%) were biopsy-confirmed renal cell carcinoma (RCC). No complications ≥ Clavien Grade III occurred and 36 patients (76.6%) were discharged the same day. Initial treatment success rate was 91.7% (n = 44/48); three treatment failures were managed with salvage radiofrequency ablation and one with robotic partial nephrectomy. Median follow-up was 50.4 months (interquartile range 29.0-65.5). The 5-year local recurrence-free survival was 81.4% in biopsy-confirmed RCC patients and 81.0% in all patients. Five-year metastasis-free survival was 93.3% and 97.1%, respectively, and 5-year overall survival was 92.3% and 90.6%, respectively. Five-year cancer-specific survival was 100% for both biopsy-confirmed RCC and all patient groups. Conclusions: IRE has low morbidity, but suboptimal intermediate-term oncologic outcomes compared with conventional thermal ablation techniques for small low-complexity tumors. Use of IRE should be restricted to select cases.

Causes and prevention of kidney stones: separating myth from fact

Despite high-level evidence supporting the use of pharmacotherapy therapy for the prevention of kidney stones, adherence to medications is often poor because of side-effects, inconvenience and cost. Furthermore, with a desire for more 'natural' products, patients seek dietary and herbal remedies over pharmacotherapy. However, patients are often unaware of the potential side-effects, lack of evidence and cost of these remedies. Therefore, in the present review we examine the evidence for a few of the commonly espoused non-prescription agents or dietary recommendations that are thought to prevent stone formation, including lemonade, fish oil (omega fatty acids), Phyllanthus niruri and the Dietary Approaches to Stop Hypertension (DASH) diet. While the present review includes only a few of the stone-modulating recommendations available to the lay community, we focussed on these four due to their prevalent use. Our goal is not to only dispel commonly held notions about stone disease, but also to highlight the lack of high-level evidence for many commonly utilised treatments.

Single-port robotic-assisted simple prostatectomy is associated with decreased post-operative narcotic use in a propensity score matched analysis

Robotic-assisted simple prostatectomy (RASP) has proven to be an effective minimally invasive option for benign prostatic enlargement (BPE) in recent years. Single-site surgery is theorized to reduce post-operative pain beyond traditional minimally invasive approaches. We sought to assess whether use of a single-port robotic platform decreases post-operative opioid use in patients undergoing robotic-assisted simple prostatectomy (RASP). A retrospective review was performed of all patients undergoing RASP our institution from November 2017 to July 2019. Demographic, intraoperative, and post-operative data, including morphine equivalent (ME) use, were collected. Patients were stratified by robotic platform utilized. Propensity score matching using nearest neighbor method was performed using prostate volume, Charlson comorbidity index (CCI), and post-op ketorolac use in 4:1 fashion. Chi-squared analysis and Kruskal-Wallis analyses were utilized. Two-hundred-and-seven men underwent RASP. After matching, 80 patients (64 multi-port, 16 single-port) were included in the analysis. Groups were comparable for age, body mass index, CCI, prostate volume, prior opioid use, and use of scheduled ketorolac post op. The single-port approach was associated with a reduction in MEs once admitted to the floor (5 vs. 11 mg, p = 0.025) and an increase in the proportion of patients who did not require any narcotics post-operatively (44 vs. 19%, p = 0.036). In a propensity matched cohort of patients undergoing RASP at a single institution, use of the single-port robotic system conferred a significant decrease in post-operative narcotic use by approximately 50%.

Single Port Robotic Surgery in Urology

PURPOSE

To provide a comprehensive review on the new da Vinci SP (single port) robotic surgical system. The published literature to date within urology and a description of the new system will be discussed.

FINDINGS

There are currently no high-quality published studies with the SP robotic system. All studies are case series, many with 10 or fewer patients. However, all studies have found the SP system to be safe and feasible in performing most urological procedures. Renal and pelvic surgery using the SP robotic system is safe and feasible in the hands of expert robotic surgeons. Long-term, high-quality data is lacking. While the current high price and the learning curve will limit the SP systems' use in many health care systems, new updates and the release of robotic surgical systems from other developers may help drive down costs and encourage uptake.

Comprehensive assessment of the morbidity of renal mass biopsy: A population-based assessment of biopsy-related complications

INTRODUCTION

We sought to assess seven-day and 30-day complications following renal mass biopsy (RMB), including mortality, hospitalizations, emergency department (ED) visits, and operative and non-operative complications and compare these to rates in population-matched controls.

METHODS

We performed a population-based, matched, retrospective cohort study of patients undergoing RMB following consultation with a urologist and axial imaging from 2003-2015 in Ontario, Canada. Data on seven-day and 30-day rates of mortality, as well as operative and non operative complications after RMB were reported. The seven-day and 30-day rates of mortality, operative and non-operative interventions, hospitalizations, and ED visits were compared to matched controls using multivariable logistic regression.

RESULTS

Among 6840 patients who underwent RMB in the study period, 24 (0.4%) and 159 (2.3%) died within seven and 30 days of their biopsy, respectively. Seven- and 30-day operative intervention rates were 79 (1.2%) and 236 (3.4%), respectively. Seven- and 30-day non-operative intervention rates were 227 (3.3%) and 529 (7.7%), respectively. Thirty-day mortality (odds ratio [OR] 8.1, 95% confidence interval [CI] 5.1-13.0), hospitalizations (OR 12.6, 95% CI 10.6-15.2), and ED visits (OR 3.8, 95% CI 3.4-4.3) were more common among patients who underwent RMB than the matched controls (p<0.001 for each).

CONCLUSIONS

Patients undergoing RMB may have a small but non-negligible increased risk of mortality, hospital readmission, and ED visits compared to matched controls. However, limitations in the granularity of the dataset limits the strength of these conclusions. Further studies are needed to confirm our results. These risks should be discussed with patients for shared decision-making and considered in the risk/benefit tradeoff for the management of small renal masses.

Initial experience with extraperitoneal robotic-assisted simple prostatectomy using the da Vinci SP surgical system

Robotic-assisted simple prostatectomy (RASP) has emerged as a safe and effective treatment option for symptomatic patients with lower urinary tract symptoms related to significant benign prostatic enlargement (BPE) above 80 g. The recent release of the da Vinci SP robotic system (Intuitive, Sunnyvale, CA, USA) continues to advance the minimally invasive nature of robotic surgical technology. We now report our institution's initial experience performing RASP using the da Vinci SP robotic system. An IRB-approved, retrospective chart review was performed of all patients undergoing robotic-assisted simple prostatectomy using the da Vinci SP surgical system in the treatment of benign prostatic enlargement by a single surgeon from March to June 2019. Pre-operative, intraoperative, and post-operative data were collected for descriptive analysis. A total of 10 men, mean age of 69 ± 4 years, with mean prostate volume of 104 ± 11 g underwent surgery. The robotic cannula and a single assistant port were utilized in all cases. No cases required conversion to a multi-port robotic platform or open approach, nor required the placement of additional assistant ports. No intraoperative or immediate post-operative complications were noted. Mean estimated blood loss was 141 ± 98 mL and operative time was 172 ± 19 min. Mean catheter time was 1.9 ± 1.8 days. One patient reported transient de novo stress urinary incontinence. Single-port RASP is a safe and effective intervention for BPE. The smaller surgical footprint from the device appears to make earlier catheter removal possible. Comparative evaluation with multi-port RASP and other modalities is warranted.

The cost of treatment and its related complications for men who receive surgery or radiation therapy for prostate cancer

INTRODUCTION

We sought to examine the costs related to treatment and treatment-related complications for patients treated with surgery or radiation for localized prostate cancer.

METHODS

We performed a population-based, retrospective cohort study of men who underwent open radical prostatectomy or radiation from 2004-2009 in Ontario, Canada. Costs, including initial treatment and inpatient hospitalization, emergency room visit, outpatient consultation, physician billings, and medication costs, were determined for five years following treatment using a validated costing algorithm. Multivariable negative binomial regression was used to assess the association between treatment modality and costs.

RESULTS

A total of 28 849 men underwent treatment for localized prostate cancer from 2004- 2009. In the five years following treatment, men who underwent radiation (n=12 675) had 21% higher total treatment and treatment-related costs than men who underwent surgery ($16 716/person vs. $13 213/person). Based on multivariable analysis, while men who underwent XRT had a lower relative cost in their first year after treatment (relative rate [RR] 0.97; 95% confidence interval [CI] 0.94-1.0; p=0.025), after year 2, annual costs were significantly higher in the radiation group compared to the surgery group (total cost for year 5, RR 1.44; 95% CI 1.17-1.76; p<0.0001). Our results were similar when restricted to young, healthy men and to older men.

CONCLUSIONS

Men who undergo radiation have significantly higher five-year total treatment-related costs compared to men who undergo open radical prostatectomy. While surgery was associated with slightly higher initial costs, radiotherapy had higher costs in subsequent years.

Platelet to white blood cell ratio predicts 30-day postoperative infectious complications in patients undergoing radical nephrectomy for renal malignancy

INTRODUCTION

We sought to examine the relationship between preoperative platelet to white blood cell ratio (PLT/WBC), a hematological marker of the systemic inflammatory response, and postoperative infectious complications following radical nephrectomy for localized renal cell carcinoma.

METHODS

We performed a retrospective cohort study of patients treated with radical nephrectomy for localized kidney cancer between January 1, 2005 and December 31, 2014 (n=6235) using the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database. Univariate and multivariate analyses were used to assess the association between PLT/WBC ratio and 30-day infectious complications, including surgical site infection, urinary tract infection (UTI), pneumonia, and sepsis. Secondarily, we examined major complications and bleeding requiring transfusion.

RESULTS

A lower PLT/WBC ratio was associated with an increased risk of sepsis, pneumonia, and UTI rates (p<0.05 for all). Furthermore, there was a significant trend of decreasing rates of sepsis and pneumonia with increasing PLT/WBC ratio across quintiles (p<0.05 for all). On multivariate analysis, patients with the lowest PLT/WBC ratios (Quintile 1) had a two-fold risk of having a postoperative infectious complication compared to patients in the highest quintile (odds ratio [OR] 2.01; 95% confidence interval [CI] 1.42-2.86; p<0.0001). Patients in Quintile 5 had a higher risk of requiring blood transfusion than those in Quintiles 2-4 (p<0.05 for all).

CONCLUSIONS

The PLT/WBC ratio represents a widely available and novel index to predict risk of infectious and bleeding complications in patients undergoing radical nephrectomy. External validation is required and the biological underpinning of this phenomenon requires further study.

The cost of intraoperative adverse events in abdominal and pelvic surgery: A systematic review

BACKGROUND

The assessment of intra-operative adverse events (iAEs) is a vastly under researched area with the potential to provide new methods on how to improve patient outcomes and hospital costs. Our objective was to determine the relationship between iAEs and total hospital costs in abdominal and pelvic surgery.

DATA SOURCES

We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework. Embase, MEDLINE and EBM Reviews online databases were searched to identify all studies that reported iAE rates and total hospital costs. We then analyzed the costing approach used in each article using the Drummond tool and evaluated articles quality using the GRADE method.

CONCLUSIONS

In total, 1709 unique references were identified through our literature search. After review, 23 were included. All studies that reported iAE rates and cost as the primary outcome found that iAEs significantly increased total hospital costs. We identified a relationship between iAEs and increased hospital costs. Future studies need to be performed to further evaluate the relationship between iAEs and cost as current studies are of low quality.

Systematic review to establish absolute standards for technical performance in surgery

BACKGROUND

Standard setting allows educators to create benchmarks that distinguish between those who pass and those who fail an assessment. It can also be used to create standards in clinical and simulated procedural skill. The objective of this review was to perform a systematic review of the literature using absolute standard-setting methodology to create benchmarks in technical performance.

METHODS

A systematic review was conducted by searching MEDLINE, Embase, PsycINFO and the Cochrane Database of Systematic Reviews. Abstracts of retrieved studies were reviewed and those meeting the inclusion criteria were selected for full-text review. The quality of evidence presented in the included studies was assessed using the Medical Education Research Study Quality Instrument (MERSQI), where a score of 14 or more of 18 indicates high-quality evidence.

RESULTS

Of 1809 studies identified, 37 used standard-setting methodology for assessment of procedural skill. Of these, 24 used participant-centred and 13 employed item-centred methods. Thirty studies took place in a simulated environment, and seven in a clinical setting. The included studies assessed residents (26 of 37), fellows (6 of 37) and staff physicians (17 of 37). Seventeen articles achieved a MERSQI score of 14 or more of 18, whereas 20 did not meet this mark.

CONCLUSION

Absolute standard-setting methodologies can be used to establish cut-offs for procedural skill assessments.

MiR-301a regulates E-cadherin expression and is predictive of prostate cancer recurrence

BACKGROUND

MicroRNAs (miRNAs) are small, noncoding RNAs that regulate gene expression post-transcriptionally. Dysregulation of miRNA has been implicated in the development and progression of prostate cancer. Through next generation miRNA sequencing, we recently identified a panel of five miRNAs associated with prostate cancer recurrence and metastasis. Of the five miRNAs, miR-301a had the strongest association with prostate cancer recurrence. Overexpression of miR-301a in prostate cancer cells, PC3, and LNCaP resulted in increased growth both in vitro and in xenografted tumors. We therefore sought to examine its role in prostate carcinogenesis in greater detail.

METHODS

We examined the effect of miR-301a expression on biochemical recurrence and metastasis among 585 men treated with radical prostatectomy for prostate cancer. We examined the mechanism of growth deregulation by miR-301a in prostate cancer cells using analysis of the miRome of prostate cancer cell lines, quantitative PCR, and Western blotting.

RESULTS

High levels of miR-301a (above the median) were associated with an increased risk of biochemical recurrence (adjusted hazard ratio [aHR] 1.42, 95% confidence interval (CI) 1.06-1.90, P = 0.002) but not of metastasis (aHR 0.84, 95%CI 0.41-1.70, P = 0.6) after adjustment for known prognostic factors. RNA transcriptome sequencing analysis of miR-301a overexpressing prostate cancer cell lines identified the tumor suppressor p63 as a potential direct miR-301a target. Transcriptome sequencing, qPCR and Western blotting showed that miR-301a induced epithelial-mesenchymal transition (EMT) in prostate cancer cells through a pathway initiated by p63 inhibition. Luciferase assay verified p63 as a direct target of miR-301a. Loss of p63 resulted in miR-205 downregulation, releasing Zeb1 and Zeb2 from inhibition, culminating in Zeb1/Zeb2 suppression of E-cadherin. This pathway of growth alteration mediated by miR-301a upregulation was shown to be valid in prostate cancer cell lines and patient-derived tumors.

CONCLUSIONS

These data indicate that miR-301a functions as an oncogene in prostate cancer by directly targeting the p63 tumor suppressor leading to loss of E-cadherin and EMT. Hence, miR-301a may serve as a novel biomarker in prostate cancer as well as a therapeutic target for prostate cancer management. Prostate 76:869-884, 2016. © 2016 Wiley Periodicals, Inc.

Survival and cardiovascular events in men treated with testosterone replacement therapy: an intention-to-treat observational cohort study

BACKGROUND

Conflicting evidence exists for the association between testosterone replacement therapy and mortality and cardiovascular events. The US Food and Drug Administration recently cautioned that testosterone replacement therapy might increase risk of heart attack and stroke, based on evidence from studies with short treatment duration and follow-up. No previous study has assessed the effect of duration of testosterone treatment on these outcomes. We aimed to assess the association between long-term use of testosterone replacement therapy and mortality, cardiovascular events, and prostate cancer diagnoses, using a time-varying exposure analysis.

METHODS

We did a population-based matched cohort study of men aged 66 years or older newly treated with testosterone replacement therapy and controls matched for age, region of residence, comorbidity, diabetes status, and index year from 2007-12 in Ontario, Canada, using data from the Ontario Drug Benefit database, the Canadian Institute for Health Information (CIHI) Discharge Abstract Database, the CIHI National Ambulatory Care Reporting System, the Ontario Health Insurance Plan database, the Ontario Myocardial Infarction Database, the Ontario Diabetes Database, the Ontario Cancer Registry, and the Registered Persons database. We assessed the association between cumulative testosterone replacement therapy exposure and mortality, cardiovascular events, and prostate cancer using marginal models with a time-varying testosterone exposure.

FINDINGS

We included 10 311 men treated with testosterone replacement therapy and 28 029 controls between Jan 1, 2007, and June 30, 2012. Over a median follow-up of 5·3 years (IQR 3·6-7·5) in the testosterone replacement therapy group and 5·1 years (3·4-7·4) in the control group, patients treated with testosterone replacement therapy had lower mortality than did controls (hazard ratio [HR] 0·88, 95% CI 0·84-0·93). Patients in the lowest tertile of testosterone exposure had increased risk of mortality (HR 1·11, 95% CI 1·03-1·20) and cardiovascular events (HR 1·26, 95% CI 1·09-1·46) compared with controls. By contrast, those in the highest tertile of testosterone exposure had decreased risk of mortality (HR 0·67, 95% CI 0·62-0·73) and cardiovascular events (HR 0·84, 95% CI 0·72-0·98), with a significant trend across tertiles (p<0·0001). Risk of prostate cancer diagnosis was decreased for those with the highest tertile of exposure (HR 0·60, 95% CI 0·45-0·80) compared with controls, but not for those with the shortest exposure.

INTERPRETATION

Long-term exposure to testosterone replacement therapy was associated with reduced risks of mortality, cardiovascular events, and prostate cancer. However, testosterone replacement therapy increased the risk of mortality and cardiovascular events with short durations of therapy. In view of the limitations of observational data and the potential for selection bias, these results warrant confirmation in a randomised trial.

FUNDING

Physicians' Services Incorporated Foundation and Ajmera Family Chair in Urologic Oncology.

The relationship between sperm viability and DNA fragmentation rates

BACKGROUND

In humans, sperm DNA fragmentation rates have been correlated with sperm viability rates. Reduced sperm viability is associated with high sperm DNA fragmentation, while conversely high sperm viability is associated with low rates of sperm DNA fragmentation. Both elevated DNA fragmentation rates and poor viability are correlated with impaired male fertility, with a DNA fragmentation rate of >30% indicating subfertility. We postulated that in some men, the sperm viability assay could predict the sperm DNA fragmentation rates. This in turn could reduce the need for sperm DNA fragmentation assay testing, simplifying the infertility investigation and saving money for infertile couples.

METHODS

All men having semen analyses with both viability and DNA fragmentation testing were identified via a prospectively collected database. Viability was measured by eosin-nigrosin assay. DNA fragmentation was measured using the sperm chromosome structure assay. The relationship between DNA fragmentation and viability was assessed using Pearson's correlation coefficient.

RESULTS

From 2008-2013, 3049 semen analyses had both viability and DNA fragmentation testing. A strong inverse relationship was seen between sperm viability and DNA fragmentation rates, with r=-0.83. If viability was ≤50% (n=301) then DNA fragmentation was ≥ 30% for 95% of the samples. If viability was ≥75% (n=1736), then the DNA fragmentation was ≤30% for 95% of the patients. Sperm viability correlates strongly with DNA fragmentation rates.

CONCLUSIONS

In men with high levels of sperm viability≥75%, or low levels of sperm viability≤ 30%, DFI testing may be not be routinely necessary. Given that DNA fragmentation testing is substantially more expensive than vitality testing, this may represent a valuable cost-saving measure for couples undergoing a fertility evaluation.

Accuracy of testosterone concentrations in compounded testosterone products

OBJECTIVE

This study aims to evaluate the accuracy of the testosterone concentrations within testosterone gels and creams manufactured by compounding pharmacies.

METHODS

Ten compounding pharmacies within Toronto area were included. Pharmacies were blinded as to the nature of the study. A standardized prescription for 50 mg of compounded testosterone gel/cream applied once daily was presented to each pharmacy. Two independently compounded batches were analyzed from each pharmacy 1 month apart. Testosterone concentrations in a 5-g sachet of Androgel® 1% (Abbott) and 5-g tube of Testim®1% (Auxilium) were evaluated as controls. Samples were analyzed independently and in a blinded fashion by the Laboratory Medicine Program at the University Health Network. Measurement of testosterone concentration was performed using a modified liquid chromatography tandem mass spectrometry validated for serum testosterone.

RESULTS

Compounded formulations included seven gels and three creams with a volume/daily dose ranging from 0.2 mL to 1.25 mL. Product cost ranged from $57.32 to $160.71 for a 30-day supply. There was significant variability both within and between pharmacies with respect to the measured concentration of testosterone in the compounded products. In contrast, the concentration of testosterone within Androgel and Testim was consistent and accurate. Collectively, only 50% (batch 1) and 30% (batch 2) of the compounding pharmacies provided a product with a testosterone concentration within ± 20% of the prescribed dose. Two pharmacies compounded products with >20% of the prescribed dose. One pharmacy compounded a product with essentially no testosterone.

CONCLUSIONS

Testosterone concentrations in compounded testosterone products can be variable and potentially compromise the efficacy and safety of treatment.