Diabetes, Obesity, and Pathological Upstaging in Renal Cell Carcinoma: Results From a Large Multi-institutional Consortium.

PURPOSE: We sought to determine whether clinical risk factors and morphometric features on preoperative imaging can be utilized to identify those patients with cT1 tumors who are at higher risk of upstaging (pT3a). MATERIALS AND METHODS: We performed a retrospective international case-control study of consecutive patients treated surgically with radical or partial nephrectomy for nonmetastatic renal cell carcinoma (cT1 N0) conducted between January 2010 and December 2018. Multivariable logistic regression models were used to study associations of preoperative risk factors on pT3a pathological upstaging among all patients, as well as subsets with those with preoperative tumors ≤4 cm, renal nephrometry scores, tumors ≤4 cm with nephrometry scores, and clear cell histology. We also examined association with pT3a subsets (renal vein, sinus fat, perinephric fat). RESULTS: Among the 4,092 partial nephrectomy and 2,056 radical nephrectomy patients, pathological upstaging occurred in 4.9% and 23.3%, respectively. Among each group independent factors associated with pT3a upstaging were increasing preoperative tumor size, increasing age, and the presence of diabetes. Specifically, among partial nephrectomy subjects diabetes (OR=1.65; 95% CI 1.17, 2.29), male sex (OR=1.62; 95% CI 1.14, 2.33), and increasing BMI (OR=1.03; 95% CI 1.00, 1.05 per 1 unit BMI) were statistically associated with upstaging. Subset analyses identified hilar tumors as more likely to be upstaged (partial nephrectomy OR=1.91; 95% CI 1.12, 3.16; radical nephrectomy OR=2.16; 95% CI 1.44, 3.25). CONCLUSIONS: Diabetes and higher BMI were associated with pathological upstaging, as were preoperative tumor size, increased age, and male sex. Similarly, hilar tumors were frequently upstaged.

Robot-assisted retroperitoneal lymph node dissection: a systematic review of perioperative outcomes.

OBJECTIVE: To assess the safety and feasibility of robot-assisted retroperitoneal lymph node dissection (R-RPLND) and to compare the perioperative outcomes of R-RPLND with open RPLND (O-RPLND), as RPLND forms an integral part of the management of testis cancer and R-RPLND is a minimally invasive treatment option for this disease. MATERIALS AND METHODS: The PubMed® , Scopus® , Cochrane Central Register of Controlled Trials, and Web of Science™ databases were searched for studies reporting perioperative outcomes of primary and post-chemotherapy R-RPLND and studies comparing R-RPLND with O-RPLND. RESULTS: The search yielded 42 articles describing R-RPLND, including five comparative studies. The systematic review included 4222 patients (single-arm studies, n = 459; comparative studies, n = 3763). Of 459 patients in the single-arm studies, 271 underwent primary R-RPLND and 188 underwent post-chemotherapy R-RPLND. For primary R-RPLND, the operative time ranged from 175 to 540 min and the major complication rate was 4.1%. For post-chemotherapy R-RPLND, the operative time ranged from 134 to 550 min and the major complication rate was 8.5%. The conversion rate to open surgery was 2.2% in primary R-RPLND and 9.0% in post-chemotherapy R-RPLND. In comparison with O-RPLND, R-RPLND was associated with a lower transfusion rate (14.5% vs 0.9%, P < 0.001) and a lower complication rate (18.5% vs 7.8%, P = 0.002). CONCLUSION: Robot-assisted RPLND has acceptable perioperative outcomes in both the primary and post-chemotherapy settings but a notable rate of conversion to open surgery in the post-chemotherapy setting. Compared with O-RPLND, R-RPLND is associated with a lower transfusion rate and fewer overall complications. Given the potential impact of selection bias, the optimal patient selection criteria for R-RPLND remain to be elucidated.

Absolute Prostate Specific Antigen after 6 Months of Androgen Deprivation Therapy Is a Predictor of Overall and Cancer-Specific Mortality in Men with Hormone-Sensitive Prostate Cancer.

PURPOSE: We sought to determine if absolute prostate specific antigen (PSA) value after 6 months of androgen deprivation therapy (ADT) is predictive of subsequent survival in patients with prostate adenocarcinoma. MATERIALS AND METHODS: We performed a retrospective review of men receiving care within the Veterans Health Administration who initiated ADT for prostate adenocarcinoma. We used low- (≤0.2 ng/ml), intermediate- (>0.2 to 4 ng/ml) and high-risk (>4 ng/ml) absolute PSA values after 6-9 months of ADT, previously described in Southwest Oncology Group trial 9346. The primary endpoints were all-cause mortality and prostate cancer-specific mortality (PCSM). Kaplan-Meier survival curves for each PSA category were estimated and log-rank test was conducted. We employed Cox regression analysis adjusted for covariates and inverse propensity score weights associated with PSA categories to estimate the PSA category association with PCSM and all-cause mortality. RESULTS: We identified 9,170 patients in our cohort. Following ADT induction, 3,508 patients had low, 3,419 had intermediate and 2,243 had high PSA values. Two- and 5-year survival rates for low, intermediate and high PSA groups were 93.9% and 85.2% vs 88.6% and 71.2% vs 63.6% and 38.6%, respectively (p <0.0001). Patients in the high and intermediate PSA categories had a 15-fold and 3-fold higher risk of PCSM compared to those with PSA <0.2 ng/ml (p <0.0001). CONCLUSIONS: Absolute PSA in hormone-sensitive prostate cancer after 6-9 months of ADT is a predictor of overall mortality and PCSM. This measure can rapidly assess the efficacy of new interventions in phase 2 clinical trials.

A Decade of Robotic-Assisted Radical Nephrectomy with Inferior Vena Cava Thrombectomy: A Systematic Review and Meta-Analysis of Perioperative Outcomes.

PURPOSE: Open radical nephrectomy with inferior vena cava thrombectomy (O-CT) is standard management for renal cell carcinoma with inferior vena cava thrombus. First reported a decade ago, robotic-assisted radical nephrectomy with inferior vena cava thrombectomy (R-CT) is a minimally invasive option for this disease. We aimed to perform a systematic review to assess the safety and feasibility of R-CT in terms of perioperative outcomes and compare the outcomes between R-CT and O-CT. MATERIALS AND METHODS: The PubMed®, Scopus®, Cochrane Central Register of Controlled Trials and Web of ScienceTM databases were searched using the free-text and MeSH terms "renal cell carcinoma," "inferior vena cava," "thrombosis" or "thrombus," "robot" and "thrombectomy." Studies reporting perioperative outcomes of R-CT and studies comparing R-CT with O-CT were included. The review was done in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. RESULTS: The search retrieved 28 articles describing R-CT, including 7 comparative studies. This systematic review included 1,375 patients, out of which 329 patients were in single-arm studies and 1,046 patients were in comparative studies. Of the 329 patients who underwent R-CT, 14.7% were level I, 60.9% level II, 20.4% level III and 2.5% level IV thrombus. Operative time ranged from 150 to 530 minutes; blood transfusion was administered in 38.2% (126). The overall complication rate was 30.3% (99). R-CT, in comparison to O-CT, was associated with a lower blood transfusion rate (18.4% vs 64.3%, p=0.002) and a lower complication rate (14.5% vs 36.7%, p=0.005). Major complication and 30-day mortality rates were similar in both groups. CONCLUSIONS: R-CT has acceptable perioperative outcomes in carefully selected patients. Compared with O-CT, R-CT is associated with a lower blood transfusion rate and fewer overall complications. In experienced hands with carefully selected patients, R-CT is feasible and safe, with acceptable outcomes; however, selection bias limits definitive inference of these results, and optimal patient selection criteria remain to be described.

Development and implementation of competency-based assessment for urological ultrasound training using SonoSim: A preliminary evaluation.

INTRODUCTION: Urology residents are encouraged to learn ultrasound (U/S) imaging, yet there are few tools available for teaching and assessing a resident`s competence. The aim of this study was to test the new SonoSim LiveScan® and to propose a competency-based assessment model for the urology graduate medical education. MATERIALS AND METHODS: Urology residents attended an interactive training session covering the urological U/S techniques guided by the assessment model developed by the authors. Faculty members evaluated the residents using defined objectives, and the residents were surveyed on their comfort level for performing each of the model tasks. A subset of the residents then underwent a structured testing using the SonoSim LiveScan device 6 months following the training. The model developed assessed: general U/S setup, structure identification, and pathologic clinical scenarios. RESULTS: The residents felt most comfortable in identifying the bladder (4.73/5) and the kidneys (4.53/5) during the training sessions. They felt least comfortable while testing for total ureteric obstruction (3.13/5). All the residents were confident that additional U/S training sessions would improve their comfort level in performing the assessed objectives. Resident`s assessment performed at 6 months had a median test score of 15.5/20 and the assessment scores increased with resident seniority. Self-reported comfort, however, did not seem to correlate with seniority. In general, the residents felt that the SonoSim device was highly functional (4.4/5) and the pathologic assessments in particular were very helpful (4.4/5). CONCLUSIONS: Through pilot testing, we propose that a competency-based assessment used with the SonoSim LiveScan could guide the resident`s education through the acquisition of U/S skills and warrants testing in a larger cohort.

Long-Term Surveillance of Complex Cystic Renal Masses and Heterogeneity of Bosniak 3 Lesions.

PURPOSE: We sought to better characterize the frequency of Bosniak cyst class changes, identify predictors of change and progression, determine the average growth rate of cysts and validate the safety of active surveillance. MATERIALS AND METHODS: Consecutive patients referred for the management of complex cysts (Bosniak 2F or greater) were included in analysis. All imaging studies were reevaluated and any stage change was reviewed with a blinded genitourinary radiologist. Bosniak 3 cysts were subclassified as 3s-septated enhancing Bosniak cysts and 3n-cysts with wall or septation-only nodularity. A multivariate Cox proportional hazards model was used to identify predictors of the Bosniak classification change. Kaplan-Meier curves were applied to analyze Bosniak cyst progression and regression. RESULTS: A total 140 lesions were included in study, necessitating review of a total of 1,011 abdominal scans in 111 patients. Median followup was 46 months (IQR 23-65.5) and patients underwent a mean of 6.8 diagnostic scans. On multivariate analysis nodular cysts progressed (HR 6.16, 95% CI 2.58-14.72, p <0.00004) and entirely endophytic cysts were less likely to progress (HR 0.21, 95% CI 0.05-0.85, p = 0.028). On Kaplan-Meier analysis Bosniak 3s cysts were more likely to regress while Bosniak 3n cysts were more likely to progress than 3s cysts (p = 0.0178 and 0.0002, respectively). The growth rate of 3n and 2F cysts was 0.19 and 0.11 cm per year (p = 0.0493 and 0.0327, respectively). Locally advanced or metastatic disease did not develop in any patient. CONCLUSIONS: A diagnostic change in Bosniak 3s and 2F cysts is common and Bosniak 3n cysts behave more like Bosniak 4 cysts. Most complex kidney cysts can be safely monitored without intervention and the interval between serial imaging procedures should be increased.

Impact of Finasteride on Survival in Bladder Cancer: A Retrospective Multi-institutional Database Analysis.

INTRODUCTION: Androgen suppression therapy has been associated with a lower incidence of bladder cancer (BCa) or improved overall/cancer-specific survival. Results are ofent conflicting; therefore, we aim to assess the impact of use of finasteride on overall survival (OS) for BCa using multi-institutional database. METHODS: The South Texas Veterans Healthcare System from 5 medical centers was queried for patients with BCa with or without use of finasteride after diagnosis of BCa. The primary outcome was the impact of finasteride use after diagnosis on the OS in BCa and in the high-risk Non-muscle invasive BCa (NMIBC) cohort. RESULTS: A total of 1890 patients were included, amongst which 619 (32.8%) men were classified as finasteride users and 1271 (67.2%) men as controls. At a median (IQR) follow up of 53.8 (27.4, 90.9) months, death due to any cause was noted in 272 (43.9%) finasteride-treated, and 672 (49.3%) control groups (P = .028). The patients in the finasteride group had significantly better OS in overall cohort (112.1 months vs. 84.8 months, P < .001) as well as in the NMIBC cohort (129.3months vs. 103.2 months, P = .0046). The use of finasteride was independently associated with improved OS in both, overall cohort (HR 0.74, 95% CI 0.63-0.86; P < .001) and in the NMIBC cohort (HR = 0.71, 95% CI 0.55-0.93; P = .011). CONCLUSION: Finasteride use is associated with the improved overall survival in patients with BCa, specifically in patients with NMIBC. We, further, propose a randomized clinical trial to investigate the use of finasteride in BCa patients.

Patency outcomes of primary inferior vena cava repair in radical nephrectomy and tumor thrombectomy.

OBJECTIVE: The reconstruction of inferior vena cava (IVC) during radical nephrectomy and venous tumor thrombectomy (RN-VTT) is mostly performed with primary repair or with a patch/graft. We sought to systematically evaluate the outcomes of IVC patency over short- to intermediate-term follow-up for patients undergoing primary repair of IVC and to assess the association with survival. METHODS: A retrospective review of patients undergoing RN-VTT between January 2013 and August 2018 was conducted. Patients were followed until death, last available follow-up, or March 2022. The patency outcomes and IVC diameters were studied using follow-up cross-sectional imaging. The χ2 test, Student t test, and Kaplan-Meier survival analysis were used. RESULTS: Seventy-seven patients were included. The mean age was 59.2 ± 12.2 years and 45.4% had Mayo classification level III thrombus or higher. At a median follow-up of 36.5 months (13.3-60.7 months), the 3-year overall survival (OS) was 64%. Sixty patients underwent primary repair of the IVC and 48 of these patients were assessed for IVC patency. Ten patients (20.8%) developed caval occlusion, either from recurrent tumor (8.3%), new-onset bland thrombus (8.3%), or stenosis (4.2). The IVC patency seemed to be a significant predictor of OS (hazard ratio, 2.85; P = .021). Although the IVC diameters decreased significantly at the 3-month postoperative scan at the infrarenal (P = .019), renal (P < .001), and suprarenal (P < .001) levels, they did not decrease further on long-term follow-up imaging. CONCLUSIONS: IVC reconstruction with primary repair results in an overall patency rate of 80.2% with only a 4.0% rate of stenosis. Recurrence of tumor thrombus (8.3%) or bland thrombus (8.3%) are the predominant reasons for IVC occlusion after RN-VTT, and this outcome is associated with poor OS.

Volumetric Analysis of Renal Masses as Predictors of Partial Nephrectomy Outcomes.

Objective: To examine the role of endophytic tumor volume (TV) assessment (endophycity) on perioperative partial nephrectomy (PN) outcomes. Patients and Methods: Retrospective review of 212 consecutive laparoscopic and open partial nephrectomies from single institution using preoperative imaging and 1-year follow-up. Demographics, comorbidities, RENAL nephrometry scores, and all peri- and postoperative outcomes were recorded. Volumetric analysis performed using imaging software, independently assessed by two blinded radiologists. Univariate and multivariate statistical analysis were completed to assess predictive value of endophycity for all clinically meaningful outcomes. Results: Among those undergoing minimally invasive surgery (MIS), lower tumor endophycity was associated with higher likelihood of trifecta outcome (negative surgical margin, <10% decline in estimated glomerular filtration rate, the absence of complications) irrespective of max tumor size. For MIS, estimated blood loss increased with greater tumor endophycity regardless of tumor size. Among those who underwent open partial nephrectomy, lower tumor endophycity was associated with trifecta outcomes for tumors >4 cm only. On multivariate analysis with log-scaled odds ratios (OR), tumor endophycity and total kidney volume had the strongest correlation with tumor-related complications (OR = 3.23, 2.66). The analysis identified that tumor endophycity and TV on imaging were inversely correlated with of trifecta outcomes (OR = 0.53 for both covariates). Conclusions: Volumetric assessment of tumor endophycity performed well in identifying PN outcomes. As automated imaging software improves, volumetric analysis may prove to be a useful adjunct in preoperative planning and patient counseling.

Chronic kidney damage pathology score for systematic assessment of the non-neoplastic kidney tissue and prediction of post-operative renal function outcomes.

To establish a systematic histological assessment of non-neoplastic kidney (NNK) tissue at the time of nephrectomy to evaluate a patient's risk of developing post-operative renal dysfunction, a combined prospective pathologic assessment of the NNK and a retrospective clinical chart review was conducted. A blinded nephropathologist performed standardized assessment of glomerular sclerosis, tubulointerstitial fibrosis, arteriosclerosis, and hyaline arteriolosclerosis. Combined these formulated the chronic kidney damage pathology score (CKDPS). Multivariate logistic regression models were developed to assess the effect of CKDPS and other clinical factors on renal function up to 24 months following nephrectomy (partial or radical). 156 patients were included in the analysis with a median age of 60 years. 70% patients underwent radical nephrectomy. A history of hypertension and/or diabetes was present in 55.8% and 22.1%, respectively. Higher CKDPS (particularly glomerular global sclerosis and arteriosclerosis scores), radical nephrectomy, and reduced baseline estimated glomerular filtration rate (eGFR) were associated with worsening post-operative renal function outcomes. The systematic assessment of non-neoplastic kidney tissue at the time of renal surgery can help identify patients at risk of post-operative renal dysfunction. CKDPS represents a standardized and prognostically relevant histologic reporting system for non-neoplastic kidney tissue.

Screening logs from a pilot randomized controlled trial of radical cystectomy versus chemoradiation therapy for muscle-invasive bladder cancer.

INTRODUCTION AND OBJECTIVES: There is growing interest in a bladder preservation approach using chemoradiation therapy with transurethral resection of bladder tumor (TURBT), i.e., combined modality treatment (CMT), for muscle-invasive bladder cancer (MIBC). We have initiated a pilot study to determine feasibility of conducting a larger-scale clinical trial comparing CMT to radical cystectomy (RC) in patients with MIBC. Here we present the screening logs from the recruitment phase of this trial. METHODS: Patients who were diagnosed to have MIBC after TURBT between April 2016 and August 2017 and considered to be candidates for surgery were enrolled in this prospective, single center, randomized controlled pilot feasibility trial and scheduled to undergo RC (with neoadjuvant chemotherapy if appropriate) or CMT. RESULTS: Of 62 patients screened during the recruitment phase, only 5 were found to be suitable candidates for either treatment modality hence eligible for randomization. The reasons for exclusion were as follows: multifocal disease (n = 24, 40%), variant histology (n = 15, 25%), previous pelvic radiation (n = 6, 10%), severe lower urinary tract symptoms (n = 5, 8.3%), unwillingness to be enrolled (n = 8, 13.3%), and receipt of neoadjuvant chemotherapy (n = 2, 3.3%). One of the 5 eligible patients was randomized to CMT but was subsequently switched to RC because of a high tumor burden, 1 was randomized to RC, 2 were randomized to CMT but subsequently underwent TURBT and were considered ineligible because of extensive bladder disease, and 1 elected to undergo RC. CONCLUSIONS: We identified many patients with MIBC over a period of 16 months. However, the number of patients eligible to receive chemotherapy and in whom cystectomy and radiation therapy were both valid options was not as high as previously reported in retrospective CMT series. Many patients were excluded after TURBT. Our preliminary data indicate that only a very small subset of patients with MIBC are ideal candidates for CMT. Further research is required to identify patients who are suitable for CMT.

Nuclear NADPH oxidase-4 associated with disease progression in renal cell carcinoma.

Nuclear NADPH oxidase-4 (Nox4) is a key component of metabolic reprogramming and is often overexpressed in renal cell carcinoma (RCC). However, its prognostic role in RCC remains unclear. Here we examined the significance of nuclear Nox4 on disease progression and development of drug resistance in advanced RCC. We analyzed human RCC tissue from multiple regions in the primary index tumor, cancer-associated normal adjacent parenchyma, intravascular tumor in locally advanced cancer patients. We found that the higher nuclear Nox4 expression was significantly associated with progression and death. These findings were consistent after controlling for other competing clinical variables. In contrast, patients with lower nuclear Nox4, even in higher stage RCC had better prognosis. We identified a subset of patients with high nuclear Nox4 who had rapid disease progression or died within 6 months of surgery. In addition, higher nuclear Nox4 level correlated with resistance to targeted therapy and immunotherapy. Western blotting performed on fresh human RCC tissue as well as cell-lines revealed increased nuclear Nox4 expression. Our data support an important prognostic role of Nox4 mediated regulation of RCC independent of other competing variables. Nox4 localizes to the nucleus in high-grade, high-stage RCC. Higher nuclear Nox4 has prognostic significance for disease progression, poor survival, and development of drug resistance in RCC.

Incidence and anatomic presentation of cutaneous malignant melanoma in central Canada during a 50-year period: 1956 to 2005.

BACKGROUND: Incidence rates of cutaneous malignant melanoma (CMM) have increased worldwide. Long-term studies examining rates and anatomic site-specific incidence on a population-based level are infrequent. OBJECTIVE: We sought to examine the historical changes in the incidence and anatomic site presentation of CMM during a 50-year period in Manitoba, Canada. METHODS: Using population-based data, all first diagnoses of CMM reported between 1956 and 2005 were identified. Age-specific rates, age-standardized incidence rates, and anatomic sites were recorded. RESULTS: Incidence rates of CMM slowed for each sex beginning in 1981 for female patients and 1992 for male patients. Annual percent change revealed decreasing rates among male patients younger than 40 years (1992-2005: -5.3% [P = .03]) and female patients younger than 40 years (1987-2005: -1.8% [P = .15]). Similarly, middle-aged individuals (age 40-59 years) also had diminished annual percent change (men 1992-2005: 0.6% [P = .65]; women 1983-2005: -0.3% [P = .68]). The annual percent change for older men and women (60-79 and > or =80 years) continued to increase. Anatomic site-specific analyses revealed that the trunk was the most frequent site of CMM for young male patients (<60 years) whereas the lower extremities were the most common among young female patients (<60 years). Incidence rates for each site, however, are slowing. Among those aged 60 years and older, the rates for each anatomic site increased. LIMITATIONS: Determining changes in tumor thickness would have been useful in determining whether the nature of tumors have changed over time; however, this is not recorded in our registry. CONCLUSION: The rates of CMM are slowing; however, this change is confined to younger individuals. Anatomic site-specific CMMs are changing; rates among older individuals continue to increase for both sexes.

Quality and Quantity in Kidney Cancer Surgery: The Role of Nonneoplastic Kidney and Kidney Volumetrics in Predicting Postoperative Renal Function.

Objectives: To model renal function 2 years following radical nephrectomy with quantitative analyses using clinical, histopathologic, and renal composite cortical volumes (CCV). Methods: This retrospective study involved an assessment of the nonneoplastic kidney tissue by three blinded nephropathologists using modified Banff 1997 criteria for renal allograft pathology. Volumetric image acquisition was obtained by three independent radiologists using preoperative imaging. A 2-year estimated glomerular filtration (eGFR) calculator was created. Results: Among the 126 patients, median age was 60 years; median CCV, 398.1 cm3; preoperative eGFR, 77 mL/min/1.73 m2; and 2-year postoperative eGFR, 54 mL/min/1.73 m2. Of the subjects, 64% had hypertension, 26% diabetes, and 37% were smokers. Increasing age, glomerulopathy/sclerosis, tubulointerstitial scarring, and arteriosclerosis were statistically significantly and adversely associated with eGFR. Conversely, increasing CCV was associated with a higher eGFR. Conclusions: Quantitative analysis of the nephrectomized kidney in conjunction with patient age can accurately predict renal function at 2 years.

Initial Evaluation of Computer-Assisted Radiologic Assessment for Renal Mass Edge Detection as an Indication of Tumor Roughness to Predict Renal Cancer Subtypes.

OBJECTIVE: To develop software to assess the potential aggressiveness of an incidentally detected renal mass using images. METHODS: Thirty randomly selected patients who underwent nephrectomy for renal cell carcinoma (RCC) had their images independently reviewed by engineers. Tumor "Roughness" was based on image algorithm of tumor topographic features visualized on computed tomography (CT) scans. Univariant and multivariant statistical analyses are utilized for analysis. RESULTS: We investigated 30 subjects that underwent partial or radical nephrectomy. After excluding poor image-rendered images, 27 patients remained (benign cyst = 1, oncocytoma = 2, clear cell RCC = 15, papillary RCC = 7, and chromophobe RCC = 2). The mean roughness score for each mass is 1.18, 1.16, 1.27, 1.52, and 1.56 units, respectively (p < 0.004). Renal masses were correlated with tumor roughness (Pearson's, p=0.02). However, tumor size itself was larger in benign tumors (p=0.1). Linear regression analysis noted that the roughness score is the most influential on the model with all other demographics being equal including tumor size (p=0.003). CONCLUSION: Using basic CT imaging software, tumor topography ("roughness") can be quantified and correlated with histologies such as RCC subtype and could lead to determining aggressiveness of small renal masses.