Prostate cancer in transgender women: considerations for screening, diagnosis and management.

Transgender individuals represent 0.55% of the US population, equivalent to 1.4 million transgender adults. In transgender women, feminisation can include a number of medical and surgical interventions. The main goal is to deprive the phenotypically masculine body of androgens and simultaneously provide oestrogen therapy for feminisation. In gender-confirming surgery (GCS) for transgender females, the prostate is usually not removed. Due to limitations of existing cohort studies, the true incidence of prostate cancer in transgender females is unknown but is thought to be less than the incidence among cis-gender males. It is unclear how prostate cancer develops in androgen-deprived conditions in these patients. Six out of eleven case reports in the literature presented with metastatic disease. It is thought that androgen receptor-mediated mechanisms or tumour-promoting effects of oestrogen may be responsible. Due to the low incidence of prostate cancer identified in transgender women, there is little evidence to drive specific screening recommendations in this patient subpopulation. The treatment of early and locally advanced prostate cancer in these patients warrants an individualised thoughtful approach with input from patients' reconstructive surgeons. Both surgical and radiation treatment for prostate cancer in these patients can profoundly impact the patient's quality of life. In this review, we discuss the evidence surrounding screening and treatment of prostate cancer in transgender women and consider the current gaps in our knowledge in providing evidence-based guidance at the molecular, genomic and epidemiological level, for clinical decision-making in the management of these patients.

Displacement of Lower Pole Stones During Retrograde Intrarenal Surgery Improves Stone-free Status: A Prospective Randomized Controlled Trial.

PURPOSE: Lower pole renal stones are associated with the lowest stone-free status of any location in the urinary tract during retrograde intrarenal surgery. Prior work has suggested displacing lower pole stones to a more accessible part of the kidney to improve stone-free status. We sought to prospectively compare the efficacy of laser lithotripsy in situ vs after displacement during retrograde intrarenal surgery for lower pole stones. MATERIALS AND METHODS: Between July 2017 and May 2022 patients undergoing retrograde intrarenal surgery for lower pole stones were randomized into an in situ or displacement group. Demographics, comorbidities, and operative parameters were documented. Primary outcome was stone-free status, determined by combination of abdominal x-ray and renal ultrasound at 30-day follow-up. Secondary outcomes included operative time, 30-day complications, emergency department visits, and readmissions. RESULTS: A total of 138 patients (69 per group) were enrolled and analyzed. Baseline characteristics were similar between groups. Stone-free status significantly favored the displacement group over the in situ group (95% vs 74%, P = .003, n=62 in each group). Operative time, total laser energy usage, 30-day complications, and 30-day emergency department visits or hospital readmissions were similar between groups. On multivariate analysis only study group allocation was significantly associated with stone-free status (P = .024). CONCLUSIONS: Basket displacement of lower pole stones results in a significantly higher stone-free status compared to in situ lithotripsy. The technique is simple, atraumatic, and requires no additional equipment costs and little additional operative time, making it a practical tool in the treatment of lower pole stones.

Prostate MRI percentage tumor involvement or "PI-RADS percent" as a predictor of adverse surgical pathology.

BACKGROUND: This study assesses magnetic resonance imaging (MRI) prostate % tumor involvement or "PI-RADs percent" as a predictor of adverse pathology (AP) after surgery for localized prostate cancer (PCa). Two separate variables, "All PI-RADS percent" (APP) and "Highest PI-RADS percent" (HPP), are defined as the volume of All PI-RADS 3-5 score lesions on MRI and the volume of the Highest PI-RADS 3-5 score lesion each divided by TPV, respectively. METHOD: An analysis was done of an IRB approved prospective cohort of 557 patients with localized PCa who had targeted biopsy of MRI PIRADs 3-5 lesions followed by RARP from April 2015 to May 2020 performed by a single surgeon at a single center. AP was defined as ISUP GGG ≥3, pT stage ≥T3 and/or LNI. Univariate and multivariable analyses were used to evaluate APP and HPP at predicting AP with other clinical variables such as Age, PSA at surgery, Race, Biopsy GGG, mpMRI ECE and mpMRI SVI. Internal and External Validation demonstrated predicted probabilities versus observed probabilities. RESULTS: AP was reported in 44.5% (n = 248) of patients. Multivariable regression showed both APP (odds ratio [OR]: 1.10, 95% confidence interval [CI]: 1.04-1.14, p = 0.0007) and HPP (OR: 1.10; 95% CI: 1.04-1.16; p = 0.0007) were significantly associated with AP with individual area under the operating curves (AUCs) of 0.6142 and 0.6229, respectively, and AUCs of 0.8129 and 0.8124 when incorporated in models including preoperative PSA and highest biopsy GGG. CONCLUSIONS: Increasing PI-RADS Percent was associated with a higher risk of AP, and both APP and HPP may have clinical utility as predictors of AP in GGG 1 and 2 patients being considered for AS. PATIENT SUMMARY: Using PIRADs percent to predict AP for presurgical patients may help risk stratification, and for low and low volume intermediate risk patients, may influence treatment decisions.

Exosomes as A Next-Generation Diagnostic and Therapeutic Tool in Prostate Cancer.

Extracellular vesicles (EVs) have brought great momentum to the non-invasive liquid biopsy procedure for the detection, characterization, and monitoring of cancer. Despite the common use of PSA (prostate-specific antigen) as a biomarker for prostate cancer, there is an unmet need for a more specific diagnostic tool to detect tumor progression and recurrence. Exosomes, which are EVs that are released from all cells, play a large role in physiology and pathology, including cancer. They are involved in intercellular communication, immune function, and they are present in every bodily fluid studied-making them an excellent window into how cells are operating. With liquid biopsy, EVs can be isolated and analyzed, enabling an insight into a potential therapeutic value, serving as a vehicle for drugs or nucleic acids that have anti-neoplastic effects. The current application of advanced technology also points to higher-sensitivity detection methods that are minimally invasive. In this review, we discuss the current understanding of the significance of exosomes in prostate cancer and the potential diagnostic value of these EVs in disease progression.

A risk calculator to inform the need for a prostate biopsy: a rapid access clinic cohort.

BACKGROUND: Prostate cancer (PCa) represents a significant healthcare problem. The critical clinical question is the need for a biopsy. Accurate risk stratification of patients before a biopsy can allow for individualised risk stratification thus improving clinical decision making. This study aims to build a risk calculator to inform the need for a prostate biopsy. METHODS: Using the clinical information of 4801 patients an Irish Prostate Cancer Risk Calculator (IPRC) for diagnosis of PCa and high grade (Gleason ≥7) was created using a binary regression model including age, digital rectal examination, family history of PCa, negative prior biopsy and Prostate-specific antigen (PSA) level as risk factors. The discrimination ability of the risk calculator is internally validated using cross validation to reduce overfitting, and its performance compared with PSA and the American risk calculator (PCPT), Prostate Biopsy Collaborative Group (PBCG) and European risk calculator (ERSPC) using various performance outcome summaries. In a subgroup of 2970 patients, prostate volume was included. Separate risk calculators including the prostate volume (IPRCv) for the diagnosis of PCa (and high-grade PCa) was created. RESULTS: IPRC area under the curve (AUC) for the prediction of PCa and high-grade PCa was 0.6741 (95% CI, 0.6591 to 0.6890) and 0.7214 (95% CI, 0.7018 to 0.7409) respectively. This significantly outperforms the predictive ability of cancer detection for PSA (0.5948), PCPT (0.6304), PBCG (0.6528) and ERSPC (0.6502) risk calculators; and also, for detecting high-grade cancer for PSA (0.6623) and PCPT (0.6804) but there was no significant improvement for PBCG (0.7185) and ERSPC (0.7140). The inclusion of prostate volume into the risk calculator significantly improved the AUC for cancer detection (AUC = 0.7298; 95% CI, 0.7119 to 0.7478), but not for high-grade cancer (AUC = 0.7256; 95% CI, 0.7017 to 0.7495). The risk calculator also demonstrated an increased net benefit on decision curve analysis. CONCLUSION: The risk calculator developed has advantages over prior risk stratification of prostate cancer patients before the biopsy. It will reduce the number of men requiring a biopsy and their exposure to its side effects. The interactive tools developed are beneficial to translate the risk calculator into practice and allows for clarity in the clinical recommendations.

External Evaluation of a Novel Prostate Cancer Risk Calculator (ProstateCheck) Based on Data from the Swiss Arm of the ERSPC.

PURPOSE: We externally validated a novel prostate cancer risk calculator based on data from the Swiss arm of the ERSPC and assessed whether the risk calculator (ProstateCheck) is superior to the PCPT-RC and SWOP-RC in an independent Swiss cohort. MATERIALS AND METHODS: Data from all men who underwent prostate biopsy at an academic tertiary care center between 2004 and 2012 were retrospectively analyzed. The probability of having any prostate cancer or high grade prostate cancer (Gleason score 7 or greater) on prostate biopsy was calculated using the ProstateCheck. Risk calculator performance was assessed using calibration and discrimination, and additionally compared with the PCPT-RC and SWOP-RC by decision curve analyses. RESULTS: Of 1,615 men 401 (25%) were diagnosed with any prostate cancer and 196 (12%) with high grade prostate cancer. Our analyses of the ProstateCheck-RC revealed good calibration in the low risk range (0 to 0.4) and moderate overestimation in the higher risk range (0.4 to 1) for any and high grade prostate cancer. The AUC for the discrimination of any prostate cancer and high grade prostate cancer was 0.69 and 0.72, respectively, which was slightly but significantly higher compared to the PCPT-RC (0.66 and 0.69, respectively) and SWOP-RC (0.64 and 0.70, respectively). Decision analysis, taking into account the harms of transrectal ultrasound measurement of prostate volume, showed little benefit for ProstateCheck-RC, with properties inferior to those of the PCPT-RC and SWOP-RC. CONCLUSIONS: Our independent external evaluation revealed moderate performance of the ProstateCheck-RC. Its clinical benefit is limited, and inferior to that of the PCPT-RC and SWOP-RC.

Improving multivariable prostate cancer risk assessment using the Prostate Health Index.

OBJECTIVES: To analyse the clinical utility of a prediction model incorporating both clinical information and a novel biomarker, p2PSA, in order to inform the decision for prostate biopsy in an Irish cohort of men referred for prostate cancer assessment. PATIENTS AND METHODS: Serum isolated from 250 men from three tertiary referral centres with pre-biopsy blood draws was analysed for total prostate-specific antigen (PSA), free PSA (fPSA) and p2PSA. From this, the Prostate Health Index (PHI) score was calculated (PHI = (p2PSA/fPSA)*√tPSA). The men's clinical information was used to derive their risk according to the Prostate Cancer Prevention Trial (PCPT) risk model. Two clinical prediction models were created via multivariable regression consisting of age, family history, abnormality on digital rectal examination, previous negative biopsy and either PSA or PHI score, respectively. Calibration plots, receiver-operating characteristic (ROC) curves and decision curves were generated to assess the performance of the three models. RESULTS: The PSA model and PHI model were both well calibrated in this cohort, with the PHI model showing the best correlation between predicted probabilities and actual outcome. The areas under the ROC curve for the PHI model, PSA model and PCPT model were 0.77, 0.71 and 0.69, respectively, for the prediction of prostate cancer (PCa) and 0.79, 0.72 and 0.72, respectively, for the prediction of high grade PCa. Decision-curve analysis showed a superior net benefit of the PHI model over both the PSA model and the PCPT risk model in the diagnosis of PCa and high grade PCa over the entire range of risk probabilities. CONCLUSION: A logical and standardized approach to the use of clinical risk factors can allow more accurate risk stratification of men under investigation for PCa. The measurement of p2PSA and the integration of this biomarker into a clinical prediction model can further increase the accuracy of risk stratification, helping to better inform the decision for prostate biopsy in a referral population.

European Randomised Study of Screening for Prostate Cancer (ERSPC) risk calculators significantly outperform the Prostate Cancer Prevention Trial (PCPT) 2.0 in the prediction of prostate cancer: a multi-institutional study.

OBJECTIVE: To analyse the performance of the Prostate Cancer Prevention Trial Risk Calculator (PCPT-RC) and two iterations of the European Randomised Study of Screening for Prostate Cancer (ERSPC) Risk Calculator, one of which incorporates prostate volume (ERSPC-RC) and the other of which incorporates prostate volume and the prostate health index (PHI) in a referral population (ERSPC-PHI). PATIENTS AND METHODS: The risk of prostate cancer (PCa) and significant PCa (Gleason score ≥7) in 2001 patients from six tertiary referral centres was calculated according to the PCPT-RC and ERSPC-RC formulae. The calculators' predictions were analysed using the area under the receiver-operating characteristic curve (AUC), calibration plots, Hosmer-Lemeshow test for goodness of fit and decision-curve analysis. In a subset of 222 patients for whom the PHI score was available, each patient's risk was calculated as per the ERSPC-RC and ERSPC-PHI risk calculators. RESULTS: The ERSPC-RC outperformed the PCPT-RC in the prediction of PCa, with an AUC of 0.71 compared with 0.64, and also outperformed the PCPT-RC in the prediction of significant PCa (P<0.001), with an AUC of 0.74 compared with 0.69. The ERSPC-RC was found to have improved calibration in this cohort and was associated with a greater net benefit on decision-curve analysis for both PCa and significant PCa. The performance of the ERSPC-RC was further improved through the addition of the PHI score in a subset of 222 patients. The AUCs of the ERSPC-PHI were 0.76 and 0.78 for PCa and significant PCa prediction, respectively, in comparison with AUC values of 0.72 in the prediction of both PCa and significant PCa for the ERSPC-RC (P = 0.12 and P = 0.04, respectively). The ERSPC-PHI risk calculator was well calibrated in this cohort and had an increase in net benefit over that of the ERSPC-RC. CONCLUSIONS: The performance of the risk calculators in the present cohort shows that the ERSPC-RC is a superior tool in the prediction of PCa; however the performance of the ERSPC-RC in this population does not yet warrant its use in clinical practice. The incorporation of the PHI score into the ERSPC-PHI risk calculator allowed each patient's risk to be more accurately quantified. Individual patient risk calculation using the ERSPC-PHI risk calculator can be undertaken in order to allow a systematic approach to patient risk stratification and to aid in the diagnosis of PCa.

A case report of mucinous tubular and spindle cell carcinoma of the kidney.

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare type of kidney tumor that has only recently been described, with less than eighty cases in the literature. This was only recognized as a specific entity in the World Health Organization 2004 classification of Renal Cell Carcinoma (RCC). MTSCCs are polymorphic renal neoplasms characterized by small, elongated tubules lined by cuboidal cells with cords of spindled cells separated by pale mucinous stroma. We report the case of a 57 year old lady who had an incidental finding of a mass in her right kidney. The radiological features were consistent with a RCC and following a multidisciplinary team discussion she underwent a laparoscopic radical nephrectomy. Macroscopic examination revealed a well circumscribed 6.5 × 6 × 6.5 cm right lower pole mass. Histologically it was composed of elongated tubules, small tubules and papillary structures with a necrotic centre. The cells demonstrated cuboidal and spindle cell morphology. Histological grade was Fuhrman grade 2. The majority of MTSCCs are indolent, and there are only two reports of distant metastases which responded favorably to adjuvant sunitinib. To date there is no international consensus on long term surveillance of these patients. Due of the favorable prognosis with this type of tumor, MTSCC must be differentiated from papillary renal cell carcinoma to avoid administration of excessive adjuvant treatment to patients.

Selecting an Endourology Society Fellowship Program: The Candidates' Perspectives.

Introduction: Understanding the factors that influence the decision of urology residents to pursue an Endourology Society (ES) fellowship and the criteria used by applicants to rank programs may help residents and program directors (PDs) optimize the match process. In the present study, we surveyed current ES fellows to gain better insight surrounding their decision-making process. Materials and Methods: A survey was emailed to all ES fellows, comprising Endourology and Stone Disease (ESD), Laparoscopic and Robotic Surgery (MIS), and combination of ESD/MIS (COM) programs. A Likert scale ranging from 1 to 5 was used. The survey captured demographics such as geographic region, program type, duration, applicants' reasons for pursuing fellowship, criteria for ranking programs, and perceived improvements in surgical comfort levels at the end of their training. Results: Out of the 60 fellows who were surveyed, 40 (66.7%) responded. Among the respondents, 9 (22.5%) pursued ESD, 10 (25%) pursued MIS, and 21 (52.5%) pursued COM programs. The primary reason for seeking a fellowship was to improve surgical skills while increasing earning potential and enhancing research opportunities were deemed the least important. Fellows enrolled in 1-year programs were less likely to pursue fellowships for academic reasons. The two most significant factors in selecting a program were both related to gaining operative experience. Lastly, there was an increase in the level of comfort performing all endourological surgeries independently after fellowship. Conclusions: ES fellowship is seen as an opportunity to hone surgical skills and increase job competitiveness. When selecting a program, operative experience is the most important factor, and fellowship improves operative confidence. The information obtained from this study may mutually help guide future applicants and PDs in the decision process of the Endourology Match.

Reverse Trendelenburg Positioning Minimizes Stone Retropulsion During Ureteroscopic Laser Lithotripsy: A Prospective Randomized Study.

Purpose: Retropulsion of stone fragments during ureteroscopic laser lithotripsy (URSLL) remains a challenge for urologists and is associated with increased operative time and reduced stone-free rate (SFR). In this study, we compared the rate of retropulsion of ureteral stones during URSLL between the standard dorsal lithotomy (SDL) position and dorsal lithotomy position with reverse Trendelenburg (RT). Materials and Methods: Patients with ureteral stones requiring surgical intervention between May 2019 and January 2022 were randomized to undergo URSLL in either SDL or RT positions. The primary outcome of this study was stone retropulsion. Secondary outcomes included retropulsion to the kidney, SFR, operative time, 30-day emergency department visits and complications, and the need for conversion from semirigid to flexible ureteroscope. Differences between groups were evaluated using the chi-square test, Fisher exact test, Kruskal-Wallis test, or t-test. Results: A total of 114 patients were included in the study, with 57 patients in each group. There were no differences between groups in terms of baseline demographics or stone characteristics. Retropulsion was significantly less frequent in the RT group (68.4% vs 10.5%, p < 0.01). Similarly, the RT group was favored for lower risk of retropulsion into the kidney (40.4% vs 5.3%, p < 0.01), operative time (43.5 vs 33.0 minutes, p = 0.02), and need for ureteroscope conversion (16.7% vs 2.2%, p = 0.04). There was no difference in the SFR (100% vs 95%, p = 0.49). Conclusions: RT positioning during URSLL for ureteral stones significantly decreases the rate of stone retropulsion, operative time, and the need for conversion from semirigid to flexible ureteroscope.

Paediatric sutureless circumcision--an alternative to the standard technique.

INTRODUCTION: Circumcision is one of the most commonly performed surgical procedures in male children. A range of surgical techniques exist for this commonly performed procedure. The aim of this study is to assess the safety, functional outcome and cosmetic appearance of a sutureless circumcision technique. METHODS: Over a 9-year period, 502 consecutive primary sutureless circumcisions were performed by a single surgeon. All 502 cases were entered prospectively into a database including all relevant clinical details and a review was performed. The technique used to perform the sutureless circumcision is a modification of the standard sleeve technique with the use of a bipolar diathermy and the application of 2-octyl cyanoacrylate (2-OCA) to approximate the tissue edges. RESULTS: All boys in this study were pre-pubescent and the ages ranged from 6 months to 12 years (mean age 3.5 years). All patients had this procedure performed as a day case and under general anaesthetic. Complications included: haemorrhage (2.2%), haematoma (1.4%), wound infection (4%), allergic reaction (0.2%) and wound dehiscence (0.8%). Only 9 (1.8%) parents or patients were dissatisfied with the cosmetic appearance. CONCLUSION: The use of 2-OCA as a tissue adhesive for sutureless circumcisions is an alternative to the standard suture technique. The use of this tissue adhesive, 2-OCA, results in comparable complication rates to the standard circumcision technique and results in excellent post-operative cosmetic satisfaction.

Embryologic and hormonal contributors to prostate cancer in transgender women.

Transgender women, who were assigned male at birth but identify as women, may take several steps to merge their physical and psychological identities, including gender-affirming surgeries and hormone therapy. With the presence of the mature prostate gland there persists a risk for malignant transformation in this population. The recognition by the medical community and society at large that transgender women are at risk of developing prostate cancer has recently been supported by investigative efforts. The slowly emerging clinical evidence suggests that the disease is likely to be more aggressive than in cisgender men, with 6 of 9 published cases discussing metastasis reporting metastatic disease on presentation. Currently the overall prevalence appears low, pointing to evolving awareness, educational status, socioeconomic status, and late presentation. This commentary focuses on exploring the factors contributing to the incidence of prostate cancer and the biochemical and endocrine mechanisms that lead to aggressive prostate tumor development in transgender women.

Disparities in patient and system factors explain racial/ethnic disparities in delayed time to treatment in muscle invasive bladder cancer.

PURPOSE: Treatment delays in muscle invasive bladder cancer (MIBC) have been shown to be associated with worse outcomes. While every attempt is made to provide adequate treatment expeditiously, Black and Hispanic patients often experience delays at a higher rate than their White counterparts. This study aims to quantify the mechanisms that contribute to this disparity in treatment delay. METHODS: Retrospective analysis of clinical T-stages II-IVa MIBC patients who underwent surgical resection from 2004 to 2017 in the National Cancer Database. A causal inference mediation analysis using the counterfactual framework was implemented to estimate the extent to which racial/ethnic disparities in patient and system factors explain the racial/ethnic disparities in time to treatment. Mediators included income, education, comorbidities, insurance, and hospital type. RESULTS: Among 22,864 patients who met inclusion criteria, 7%, 3%, 2% were of Black, Hispanic, and Other race/ethnicity, respectively. In multivariable models, compared to White patients, Black, and Hispanic patients were associated with 26% (odds ratio = 1.26, 95% confidence interval = 1.12-1.42) and 29% (odds ratio = 1.29, 95% confidence interval = 1.07-1.55) increased odds of having a treatment delay relative to White patients. Mediation analyses suggested that 49% and 26% the treatment delay among Black and Hispanic patients, respectively, could be removed if an intervention equalized the distribution of academic treatment, education, and insurance status to that of White patients. Treatment at an academic hospital and education were the mediators that explained the largest portion of the racial/ethnic disparity in treatment delay. CONCLUSION: Black and Hispanic MIBC patients experience treatment delays when compared to White patients. Intervening upon patient and system factors could reduce substantial treatment delays. Future research is needed to identify other causes of disparities in treatment delays and may help population health initiatives to address racial/ethnic disparities in clinical settings.

Criteria Used by Endourology Society Fellowship Program Directors for the Selection and Evaluation of Fellows.

Introduction: An understanding of which trainee factors Endourology Society (ES) fellowship program directors (PDs) value may help urology residents optimize their fellowship candidacy and help current fellows optimize their fellowship performance. In the present study, we evaluated which factors are most important to ES PDs in selecting fellowship candidates and evaluating current fellows. Materials and Methods: A survey was constructed using Research Electronic Data Capture (REDCap) software and emailed to PDs of fellowships registered with the ES. Fellowships in the ES include Endourology/kidney stone disease (ESD) programs, robotic-laparoscopic surgery programs (MIS), and combination programs. A Likert scale ranging from 1 (not important) to 5 (extremely important) was used to rank the criteria for selecting and evaluating fellows. The survey captured program demographics such as geographic region, program type, and program duration. Results: Of the 52 ES PDs, 35 (67%) responded. Respondents represented 8 (23%) ESD programs, 7 (20%) MIS programs, and 20 (57%) combination programs. Furthermore, 16 (46%) represented 1-year programs and 19 (54%) represented 2-year programs. The top-five factors for candidate selection were perceived fit of the applicant, perceived level of applicant interest, initial interview, personal emails from applicants' advocates, and personal phone calls from applicants' advocates. Advocacy on behalf of the applicant appeared to be especially important for 2-year fellowships. The top-five factors for the evaluation of fellows in training were patient interactions, professionalism, attitude/demeanor, operative skills, and interactions with ancillary staff. Research productivity was of greater importance for the evaluation and selection of 2-year fellows and ESD fellows. Conclusions: Applicants for ES fellowships should focus on the initial interview and recruiting supportive mentors to advocate for their applications, particularly for 2-year programs. Although PDs value both clinical skills and research productivity, research productivity was more important for 2-year programs and ESD programs. Further research into applicant perspectives on the fellowship application process is warranted.

Do Infection-Associated Stone Subtypes Behave the Same Clinically? A Retrospective Bicenter Study.

Introduction and Objectives: Infection-associated renal stones are commonly composed of magnesium-ammonium-phosphate (MAP) and carbonate apatite (CA). The clinical implications of these two different, but closely related stone types, are unknown. We sought to compare the clinical, microbiologic, and metabolic characteristics of patients with MAP and CA stone types. Methods: We retrospectively reviewed the medical records of patients from two centers (one in the United States and one in Israel) who underwent ureteroscopy or percutaneous nephrolithotomy between 2012 and 2020 and identified patients with a predominant stone analysis component of CA or MAP and clinical data supporting an infection stone. We analyzed and compared demographic data, medical history, postoperative fever, stone and urinary microbiology, and 24-hour urine studies. Results: A total of 79 and 75 patients met the inclusion criteria for the MAP and CA cohorts, respectively. No significant difference was found in patient demographics or comorbidities between the MAP and CA cohort. Female predominance was noted in both. Although there were no significant differences in 24-hour urine parameters between the cohorts, hypercalciuria was common in both cohorts (38% and 32% of patients in the MAP and CA cohorts, respectively). Gram-negative bacteria were more common in the MAP stone cultures. Postoperative fever was significantly more common in the MAP cohort (14.7% vs 3.8%, p < 0.016). Conclusions: MAP and CA stone formers share similar demographic characteristics with a clear female predominance. MAP stones patients appear more likely to develop postoperative fever, possibly related to a higher occurrence of gram-negative bacteria in the stone cultures of the MAP cohort. Although there were no significant differences among metabolic parameters, hypercalciuria was noted in approximately a third of the cohort. The clinical significance of this finding is yet to be determined.