Topical Photodynamic Therapy Generates Bioactive Microvesicle Particles: Evidence for a Pathway Involved in Immunosuppressive Effects

Although effective in treating actinic damage, topical photodynamic therapy (PDT) has been shown to be immunosuppressive through unknown mechanisms, which could potentially limit its effectiveness. Multiple types of environmental stressors, including PDT, can produce the immunosuppressive lipid mediator platelet-activating factor (PAF). Because PAF can produce subcellular microvesicle particles (MVPs), these studies tested whether PDT can generate PAF and MVP release and whether these are involved in PDT-induced immunosuppression. Previously, topical PDT using blue light and 5-aminolevulinic acid was found to be a potent stimulus for PAF production in mice and human skin explants and human patients, and we show that experimental PDT also generates high levels of MVP. PDT-generated MVPs were independent of the PAF receptor but were dependent on the MVP-generating enzyme acid sphingomyelinase. Patients undergoing topical PDT treatment to at least 10% of body surface area showed local and systemic immunosuppression as measured by inhibition of delayed-type hypersensitivity reactions. Finally, using a murine model of contact hypersensitivity, PDT immunosuppression was blocked by genetic and pharmacologic inhibition of acid sphingomyelinase and genetic inhibition of PAF receptor signaling. These studies describe a mechanism involving MVP through which PDT exerts immunomodulatory effects, providing a potential target to improve its effectiveness.

Prognostic utility of linear segmentation in nonmetastatic renal cell carcinoma: Correlation of overall survival with muscle mass

617

Background: In renal cell carcinoma (RCC) and other solid organ malignancies, sarcopenia has been associated with decreased survival and increased perioperative complications. Traditional body composition analysis is an expensive and time extensive process. As a modifiable risk factor, more clinic friendly methods to identify patients with low muscle composition is of interest. Linear segmentation on routine imaging has been proposed as a fast, reliable and reproducible alternative. This study assesses the prognostic ability of linear segmentation in patients with nonmetastatic RCC. Methods: Patients that underwent nephrectomy for nonmetastatic RCC from 2005-2021 at an academic referral center were identified. Linear segmentation of the bilateral psoas/paraspinal muscles was completed on preoperative imaging obtained within 60 days of surgery. Cox proportional-hazards analysis was used to determine association between total muscle index and overall survival. Results: 532 (388 clear cell) patients were analyzed and a median total muscle index was 28.6 (25.8-32.5) for women and 33.3 (29.1-36.9) for men. As a binary variable, lower total muscle index was significantly associated with decreased survival in both the full (HR=1.96, 95% CI 1.32-2.90, p<0.001) and clear cell only cohorts (HR=1.78, 95% CI 1.08-2.75, p=0.022). As a continuous variable, unit increases in total muscle index were significantly associated with improved survival in the full cohort (HR=0.95, 95% CI 0.92-0.99, p=0.006) and the clear cell only cohort (HR=0.95, 95% CI 0.92-0.99, p=0.016). Conclusions: Assessment of muscle composition via linear segmentation on routinely obtained preoperative imaging is a clinically feasible technique with prognostic utility in patients with localized RCC. In this cohort of patients with nonmetastatic RCC, linear segmentation demonstrated significant associations with overall survival as a binary and continuous variable. This simplified technique may allow for routine inclusion of body composition into clinical decision making. [Table: see text]

Validating the Palacios’ future glomerular filtration rate equation with and without race

616

Background: Accurate prediction of future glomerular function rate (fGFR) following nephrectomy in renal cell carcinoma (RCC) patients is of interest. A postoperative estimated glomerular filtration (eGFR) rate ≥ 45 mL/min/1.73m2 is considered favorable, with guidelines reflecting these findings. Though nephron sparing surgery is preferable, radical nephrectomy is often the preferred oncologic surgery. Various models to predict postoperative renal function have been proposed, with a new 2021 equation by Palacios et al. exhibiting strong performance in predicting fGFR. We aim to validate this fGFR equation in a large institutional cohort using both the Chronic Kidney Disease Epidemiology (CKD-EPI) 2009 equation with race, used in the creation of the formula, as well as the CKD-EPI 2021 equation without race, which is currently the recommended CKD-EPI creatinine equation. Methods: Using an institutional database, patients that underwent partial or radical nephrectomy for RCC from 2005-2021 were identified. Patients with creatinine values preoperatively and 3-12 months postoperatively were included, with end stage renal disease serving as exclusion criteria. Correlation/bias/accuracy/precision of the fGFR equation (fGFR=35+ [preoperative eGFR x 0.65]- 18 [if radical] - [age x 0.25]+ 3 [if tumor >7cm]-2 [if diabetes]) with observed postoperative eGFR was determined by both the CKD-EPI-2021 and CKD-EPI 2009 equations. Results: 1,443 patients were included in our analysis. 71% (1,024) and 22.9% (331) patients were white and black, respectively. A majority of patients underwent radical nephrectomy (60.3%). 40% of patients had T3-T4 RCC, with 14.8% of patients having M1 disease. Median observed vs predicted fGFR was 58.0 vs 58.7 ml/min/1.73m2 for CKD-EPI 2021 and 56.0 vs 57.5 for CKD-EPI 2009. The correlation/bias/accuracy/precision of the fGFR equation was 0.805/-0.5/81.7/7.9-9.0 for CKD-EPI 2021 and 0.809/-0.8/81.3/-8.1-8 for CKD-EPI 2009 equations (Table). Conclusions: The fGFR equation accurately predicted renal function in our large and diverse institutional cohort using both the CKD-EPI 2009 including race and CKD-EPI 2021 excluding race equations. [Table: see text]

Creatinine to cystatin C ratio and mortality in renal cell carcinoma

697

Background: Creatinine and cystatin C are routinely used to assess renal function. Given creatinine originates from skeletal muscle and cystatin C is produced by nucleated cells, a creatinine to cystatin C ratio (Cr/Cys-C) may positively correlate with muscle mass. Low Cr/Cys-C has also been associated with decreased overall survival (OS) in cancer, including in a combined cohort of genitourinary malignancies. Furthermore, elevated cystatin c has been associated with shorter OS and recurrence free survival (RFS) in renal cell carcinoma (RCC). Cr/Cys-C may be a simple and affordable tool to assist with patient-specific risk stratification. We assess the ability of Cr/Cys-C to predict OS and RFS in patients with RCC. Methods: Retrospective review of a prospectively maintained database identified patients that underwent partial or radical nephrectomy for RCC from 2018-2021. Included patients had preoperative creatinine and cystatin C and 1+ year of follow up. Cr/Cys-C associations with patient/tumor characteristics were determined by generalized chi-square or Fisher’s exact tests for categorical variables and Wilcoxon rank-sum test for continuous variables. Cr/Cys-C ability to predict OS and RFS was analyzed with Kaplan-Meier method and Cox hazards models. Statistical tests were two-sided with type I error set at 0.05. Results: 219 patients were identified. Median age was 64, with most being male (67%). 62% and 29% of patients were white and black, respectively. Median eGFR was 72mL/min/1.73m2. Median (IQR) Cr/Cys-C was 1 (0.8-1.2). 55% were stage T3-T4, with 12% N1 and 16% M1 at time of surgery. 72% had clear cell histology. Low Cr/Cys-C was significantly associated with older age, males, Eastern Cooperative Oncology Group score ≥ 1, radical nephrectomy, T3-T4 stage, and metastasis. Kaplan-Meier curves showed low Cr/Cys-C association with decreased OS (p=0.0003) and RFS (p=0.0094). Cox regression analysis revealed lower Cr/Cys-C as independent predictor of decreased OS (binary HR=3.66, 95% CI 1.2-11.3, p=0.02; continuous HR=0.05, 95% 0.0-0.8, p=0.03) and RFS (binary HR=4.8, 95% CI 1.6-14.6, p=0.006; continuous HR=0.02, 95% 0.0-0.3, p=0.006;Table). Conclusions: Lower Cr/Cys-C may be associated with decreased OS and RFS in patients with RCC. [Table: see text]

Effect of race-free estimated glomerular filtration rate equations (eGFR) on oncology clinical trial eligibility for Black patients

611

Background: Race is no longer recommended in estimated glomerular filtration rate (eGFR) equations. The resulting lower eGFR may positively impact black patients, such as with earlier nephrology referral. However, the impact of race-free equations on black oncology patients–a cohort more likely to experience inferior cancer outcomes and underrepresentation in clinical trials–has not been fully examined. Here, we analyze removal of race from eGFR in black patients with cancer, specifically with regards to clinical trial eligibility. Methods: Self-identified black patients undergoing nephrectomy at a referral center from 2009-2021 were identified. Patients with end-stage renal disease were excluded. Using preoperative creatinine, height, and weight, eGFR was calculated with the Chronic Kidney Disease Epidemiology Collaboration creatinine equation with and without race (CKD-EPI-WithRace; CKD-EPI-WithoutRace, respectively), and the Modification of Diet in Renal Disease equation with and without race (MDRD-WithRace; MDRD-WithoutRace, respectively). Distribution of patients and changes within CKD stages with different equations was considered. Theoretical exclusion at commonly observed clinical trial eGFR points was then simulated based on utilization of the race coefficient. Subgroup analysis was completed on patients with stage III-IV disease only. Results: 459 self-identified black patients that underwent nephrectomy at our institution were identified, 135 of which had stage III-IV disease. On average, eGFR decreased around 10-13ml/min/1.73m2 with removal of the race coefficient (Table). 13-22%, 6-12%, and 2-3% more black patients would fall under common clinical trial cutoffs of 60, 45, or 30ml/min cutoffs, respectively, depending on the equation used (Table). Subanalysis of stage III-IV patients only were similar. Conclusions: Race free renal function equations may inadvertently result in increased exclusion of black patients from clinical trials. [Table: see text]

Association of inflammation and depression in renal cell carcinoma

658

Background: Patients with cancer experience depression at higher rates, which is associated with worse outcomes and quality of life. In renal cell carcinoma (RCC) specifically, depression is particularly prevalent. Aside from the emotional distress of a cancer diagnosis, a biologic basis for cancer associated depression is inflammation, which is highly associated with RCC as well as worse outcomes. Here, we aim to assess the association between inflammation and major depression, measured by a score of 10+ on the Patient Health Questionnaire (PHQ-8), in patients undergoing nephrectomy for nonmetastatic RCC. Methods: A retrospective review of prospectively administered PHQ-8 surveys in patients that underwent nephrectomy for nonmetastatic RCC was conducted. Patients with available preoperative PHQ-8 within 180 days before surgery were included. Association of major depression on PHQ-8 with patient/tumor characteristics were determined by Generalized chi-square test or Fisher’s exact test for categorical variables and Wilcoxon rank-sum test for continuous variables. Multivariable logistic regression was used to determine variables significantly associated with major depression on PHQ-8, including pre-operative C-Reactive Protein (CRP) independently and combined with American Joint Committee on Cancer (AJCC) staging for RCC. Results: 224 patients were analyzed, with 67% being male. Median age and BMI was 64 and 29.0, respectively. 65.2% of patients were white, and 28.6% were black. Histologically, most patients had clear cell RCC (67.4%). AJCC staging was 52.2% stage I, 5.36% stage II, and 42.41% stage III. 30.4% had an elevated CRP (>10mg/L). Median PHQ-8 score was 4, with 42 (18.8%) of patients screening positive for major depression on PHQ-8 (10+). Multivariable regression models showed elevated CRP alone (OR 2.74, 95% CI 1.02-7.40, p=0.047) and in-combination with AJCC stage I-II (OR=8.13, 95% CI 1.99-33.27, p=0.004) and III (OR=4.82, CI 1.11-20.88, p=0.035) as a predictor of major depression on PHQ-8. Conclusions: In this study of patients with nonmetastatic RCC, elevated CRP (>10mg/L) was an independent predictor of major depression on PHQ-8. [Table: see text]

Assessment of Resident Burnout After Formalization of Wellness Program

INTRODUCTION

Burnout has reached epidemic levels among resident physicians. Characterized by emotional exhaustion (EE), depersonalization, and feelings of inefficacy, burnout negatively affects patient outcomes, increases costs, and decreases physician quality of life. These negative outcomes catalyze leaders in graduate medical education to address burnout and reverse its trends. The primary aim of this project is to design a residency Wellness Program utilizing the facets of physician wellness, assess levels of burnout among resident physicians, and determine the program's effects on burnout.

MATERIALS AND METHODS

A Wellness Program was formalized at a Midwestern, military-civilian Obstetrics and Gynecology residency program for the 2019-2020 academic year. Resident wellness and perceptions were assessed at three time points (0, 6, and 12 months) through surveys consisting of free response, yes-no questions, and the Maslach Burnout Inventory Scales.

RESULTS

On average, 17 of 24 residents completed all three survey assessments. Perception of the residency program prioritization of wellness increased significantly from 52.9% to 94.4% (P = .007). Residents consistently demonstrated burnout throughout the year with low levels of EE, high levels of depersonalization, and moderate levels of personal achievement. Residents were consistently satisfied with their personal wellness (80%-92.9%) during the program. Residents wanted to see physical activity incorporated into the program.

CONCLUSIONS

This study assessed burnout during a formalization of a Wellness Program and insight on resident perceptions and wellness requests. Military medicine, graduate medical education, and other residency programs can utilize this research to better develop and study the implementation of wellness initiatives aimed at reducing burn out.

Urachal mucinous cystic tumor of low malignant potential in a polymorbid female: a case report and review of the literature

Neoplasms of the urachus are exceedingly rare, representing 0.17% of all bladder cancers. The mucinous cystic tumor of low malignant potential (MCTLMP) subtype is particularly rare with just 25 previous cases reported in the literature. Although rare, MCTLMPs are important to identify due to potential devastating complications and good cure rates with surgical removal. We present a 43 year old female with a nuanced constellation of comorbidities and confirmed MCTLMP following a workup for abdominal pain and irritative lower urinary tract symptoms. Notably, this tumor did not change in size over a 3-year course of serial imaging prior to surgical excision. This urachal MCTLMP represents roughly the 26th and one of the smallest of its subtype reported in the literature. This case illustrates the diagnosis and management of this rare urachal MCTLMP. Individual patient medical history, clinical considerations, and neoplasm characteristics are examined. Although rare, the potential for increased malignancy and potential complications necessitates surgical management and further investigation by the academic community.

Evidence for Systemic Reactive Oxygen Species in UVB-mediated Microvesicle Formation

Recent studies have implicated subcellular microvesicle particles (MVP) in the ability of ultraviolet B radiation to exert both local and systemic effects. Indeed, UVB generates MVP (UVB-MVP) in human skin and systemically following phototherapy. The current studies were designed to test the hypothesis that the ability of UVB to generate MVP was dependent upon reactive oxygen species (ROS). To that end, we tested urine samples from subjects undergoing UVB phototherapy for the presence of isoprostanes as well as the oxidized guanosine derivative 8OHdG. We also conducted a clinical study in which volar forearms of subjects were treated with localized UVB and erythema/MVP measured. The same cohort was then treated with 7 days of vitamin C (2 g day^-1 ) and vitamin E (1000 IU day^-1 ), and UVB-induced MVPs tested on the contralateral forearm. Urine specimens from subjects undergoing phototherapy were found to have increased levels of isoprostanes and 8OHdG, with maximal levels noted 8-16 h post-treatment. Treatment with antioxidant vitamins resulted in diminished UVB-generated skin MVP to baseline levels. These studies suggest that whole-body UVB generates a systemic pro-oxidative response, and that antioxidants can attenuate localized skin UVB-MVPs.

Hundred years of transperineal prostate biopsy

The earliest recorded efforts to biopsy prostate, in the early 20th century, were made through transperineal (TP) approach, with open perineal prostate biopsy (PBx) being considered the gold standard for prostate cancer (PCa) diagnosis in that era. Later, to minimize morbidity and increase diagnostic accuracy, several technical modifications and transrectal ultrasound (TRUS) assistance were incorporated. However, in the 1980s, the transrectal (TR) approach became the predominant PBx method following the introduction of TRUS-TR PBx with sextant sampling, providing a convenient and efficacious method for prostate sampling. With modernization of PCa diagnosis, a recent resurgence of the TP PBx has been observed, driven primarily by TR drawbacks of infectious complications and sampling limitations. TP PBx is rapidly emerging as the new PBx standard, being officially recommended as the initial approach for biopsy in Europe and is increasingly being conducted and studied in the United States. The modern era of TP PBx is based on the improvements in local anesthesia techniques, TP access systems, and robotic assistance. These modifications and advancements have improved the ease of use, patient comfort, and diagnostic outcomes with TP PBx. Herein, we present a history of the evolution of TP PBx spanning over 100 years and explore the basis of the technique that merits future utilization.

Keratinocyte-derived microvesicle particles mediate ultraviolet B radiation-induced systemic immunosuppression

A complete carcinogen, ultraviolet B (UVB) radiation (290-320 nm), is the major cause of skin cancer. UVB-induced systemic immunosuppression that contributes to photocarcinogenesis is due to the glycerophosphocholine-derived lipid mediator platelet-activating factor (PAF). A major question in photobiology is how UVB radiation, which only absorbs appreciably in the epidermal layers of skin, can generate systemic effects. UVB exposure and PAF receptor (PAFR) activation in keratinocytes induce the release of large numbers of microvesicle particles (MVPs; extracellular vesicles ranging from 100 to 1000 nm in size). MVPs released from skin keratinocytes in vitro in response to UVB (UVB-MVPs) are dependent on the keratinocyte PAFR. Here, we used both pharmacologic and genetic approaches in cells and mice to show that both the PAFR and enzyme acid sphingomyelinase (aSMase) were necessary for UVB-MVP generation. Our discovery that the calcium-sensing receptor is a keratinocyte-selective MVP marker allowed us to determine that UVB-MVPs leaving the keratinocyte can be found systemically in mice and humans following UVB exposure. Moreover, we found that UVB-MVPs contained bioactive contents including PAFR agonists that allowed them to serve as effectors for UVB downstream effects, in particular UVB-mediated systemic immunosuppression.

Inter- and Intra-physician variation in quantifying actinic keratosis skin photodamage

We investigated the variations in physician evaluation of skin photodamage based on a published photodamage scale. Of interest is the utility of a 10-level scale ranging from none and mild photodamage to actinic keratosis (AK). The dorsal forearms of 55 adult subjects with various amounts of photodamage were considered. Each forearm was independently evaluated by 15 board-certified dermatologists according to the Global Assessment Severity Scale ranging from 0 (less severe) to 9 (the most progressed stage of skin damage). Dermatologists rated the levels of photodamage based upon the photographs in blinded fashion. Results show substantial disagreement amongst the dermatologists on the severity of photodamage. Our results indicate that ratings could be more consistent if using a scale of less levels (5-levels or 3-levels). Ultimately, clinicians can use this knowledge to provide better interpretation of inter-rater evaluations and provide more reliable assessment and frequent monitoring of high-risk populations.