Cell Competition During Growth and Regeneration.

Tissue growth and regeneration are autonomous, stem-cell-mediated processes in which stem cells within the organ self-renew and differentiate to create new cells, leading to new tissue. The processes of growth and regeneration require communication and interplay between neighboring cells. In particular, cell competition, which is a process in which viable cells are actively eliminated by more competitive cells, has been increasingly implicated to play an important role. Here, we discuss the existing literature regarding the current landscape of cell competition, including classical pathways and models, fitness fingerprint mechanisms, and immune system mechanisms of cell competition. We further discuss the clinical relevance of cell competition in the physiological processes of tissue growth and regeneration, highlighting studies in clinically important disease models, including oncological, neurological, and cardiovascular diseases.

Gleason Grade 1 Prostate Cancer Volume at Biopsy Is Associated With Upgrading but Not Adverse Pathology or Recurrence After Radical Prostatectomy: Results From a Large Institutional Cohort.

PURPOSE: Clinical guidelines suggest that for low-grade, clinically localized prostate cancer, patients with higher volume of disease at diagnosis may benefit from definitive therapy, although the data remain unclear. Our objective was to determine associations between low-grade prostate cancer volume and outcomes in men managed with primary radical prostatectomy. MATERIALS AND METHODS: Men with cT1-2N0/xM0/x prostate cancer, prostate specific antigen at diagnosis <10 ng/mL, and Gleason grade group 1 pathology on diagnostic biopsy managed with primary radical prostatectomy were included. Outcomes were pathological upgrade at radical prostatectomy (≥Gleason grade group 2), University of California, San Francisco adverse pathology at radical prostatectomy (≥Gleason grade group 3, pT3/4, or pN1), alternate adverse pathology at radical prostatectomy (≥Gleason grade group 3, ≥pT3b, or pN1), and recurrence (biochemical failure with 2 prostate specific antigen ≥0.2 ng/mL or salvage treatment). Multivariable logistic regression models were used to estimate associations between percentage of positive cores and risk of upgrade and adverse pathology at radical prostatectomy. Multivariable Cox proportional hazards regression models were used to estimate associations between percentage of positive cores and hazard of recurrence after radical prostatectomy. RESULTS: A total of 1,029 men met inclusion criteria. Multivariable logistic regression models demonstrated significant associations between percentage of positive cores and pathological upgrade (OR 1.31, 95% CI 1.1-1.57, P < .01), but not University of California, San Francisco adverse pathology at radical prostatectomy (P = .84); percentage of positive cores was negatively associated with alternate adverse pathology (OR 0.67, 95% CI 0.48-0.93, P = .02). Multivariable Cox regression models demonstrated no association between percentage of positive cores and hazard of recurrence after radical prostatectomy (P = .11). CONCLUSIONS: In men with Gleason grade group 1 prostate cancer, tumor volume may be associated with upgrading at radical prostatectomy, but not more clinically significant outcomes of adverse pathology or recurrence.

Stability of Prognostic Estimation Using the CAPRA Score Incorporating Imaging-based vs Physical Exam-based Staging.

PURPOSE: Although official T-staging criteria for prostate cancer are based on digital rectal examination findings, providers increasingly rely on transrectal US and MRI to define pragmatic clinical stage to guide management. We assessed the impact of incorporating imaging findings into T-staging on performance of a well-validated prognostic instrument. MATERIALS AND METHODS: Patients who underwent radical prostatectomy for prostate cancer diagnosed between 2000 and 2019 with stage ≤cT3a on both digital rectal examination and imaging (transrectal US/MRI) were included. The University of California, San Francisco CAPRA (Cancer of the Prostate Risk Assessment) score was computed 2 ways: (1) incorporating digital rectal examination-based T stage and (2) incorporating imaging-based T stage. We assessed for risk changes across the 2 methods and associations of CAPRA (by both methods) with biochemical recurrence, using unadjusted and adjusted Cox proportional hazards models. Model discrimination and net benefit were assessed with time-dependent area under the curve and decision curve analysis, respectively. RESULTS: Of 2,222 men included, 377 (17%) increased in CAPRA score with imaging-based staging (P < .01). Digital rectal examination-based (HR 1.54; 95% CI 1.48-1.61) and imaging-based (HR 1.52; 95% CI 1.46-1.58) CAPRA scores were comparably accurate for predicting recurrence with similar discrimination and decision curve analyses. On multivariable Cox regression, positive digital rectal examination at diagnosis (HR 1.29; 95% CI 1.09-1.53) and imaging-based clinical T3/4 disease (HR 1.72; 95% CI 1.43-2.07) were independently associated with biochemical recurrence. CONCLUSIONS: The CAPRA score remains accurate whether determined using imaging-based staging or digital rectal examination-based staging, with relatively minor discrepancies and similar associations with biochemical recurrence. Staging information from either modality can be used in the CAPRA score calculation and still reliably predict risk of biochemical recurrence.

Phase Ib Study of the Oral Proteasome Inhibitor Ixazomib (MLN9708) and Fulvestrant in Advanced ER+ Breast Cancer Progressing on Fulvestrant.

LESSONS LEARNED: Fulvestrant is a selective estrogen receptor (ER)-downregulating antiestrogen that blocks ER transcriptional activity and is approved for ER-positive breast cancer. Fulvestrant also induces accumulation of insoluble ER and activates an unfolded protein response; proteasome inhibitors have been shown to enhance these effects in preclinical models. BACKGROUND: Fulvestrant is a selective estrogen receptor (ER)-downregulating antiestrogen that blocks ER transcriptional activity and is approved for ER-positive (+) breast cancer. Fulvestrant also induces accumulation of insoluble ER and activates an unfolded protein response; proteasome inhibitors have been shown to enhance these effects in preclinical models. METHODS: This is a single-center phase Ib study with a 3+3 design of fulvestrant and the proteasome inhibitor ixazomib (MLN9708) in patients with advanced ER+ breast cancer that was progressing on fulvestrant. A dose-escalation design allowed establishment of the ixazomib maximum tolerated dose (MTD). Secondary objectives included progression-free survival, pharmacokinetics, and tumor molecular analyses. RESULTS: Among nine evaluable subjects, treatment was well-tolerated without dose-limiting toxicities The MTD of ixazomib was 4 mg in combination with fulvestrant. Plasma concentrations of the active form of ixazomib (MLN2238) in the 4-mg dose cohort had a median (range) maximal concentration (Cmax ) of 155 (122-171) ng/mL, time of maximal concentration (Tmax ) of 1 (1-1.5) hour, terminal elimination half-life of 66.6 (57.3-102.6) hour after initial dose, and area under the curve (AUC) of 5,025 (4,160-5,345) ng*h/mL. One partial response was observed, and median progression-free survival was 51 days (range, 47-137). CONCLUSION: This drug combination has a favorable safety profile and antitumor activity in patients with fulvestrant-resistant advanced ER+ breast cancer that justifies future testing.

Plasma DNA as a "liquid biopsy" incompletely complements tumor biopsy for identification of mutations in a case series of four patients with oligometastatic breast cancer.

PURPOSE: Circulating tumor DNA in plasma may present a minimally invasive opportunity to identify tumor-derived mutations to inform selection of targeted therapies for individual patients, particularly in cases of oligometastatic disease where biopsy of multiple tumors is impractical. To assess the utility of plasma DNA as a "liquid biopsy" for precision oncology, we tested whether sequencing of plasma DNA is a reliable surrogate for sequencing of tumor DNA to identify targetable genetic alterations. METHODS: Blood and biopsies of 1-3 tumors were obtained from 4 evaluable patients with advanced breast cancer. One patient provided samples from an additional 7 tumors post-mortem. DNA extracted from plasma, tumor tissues, and buffy coat of blood were used for probe-directed capture of all exons in 149 cancer-related genes and massively parallel sequencing. Somatic mutations in DNA from plasma and tumors were identified by comparison to buffy coat DNA. RESULTS: Sequencing of plasma DNA identified 27.94 ± 11.81% (mean ± SD) of mutations detected in a tumor(s) from the same patient; such mutations tended to be present at high allelic frequency. The majority of mutations found in plasma DNA were not found in tumor samples. Mutations were also found in plasma that matched clinically undetectable tumors found post-mortem. CONCLUSIONS: The incomplete overlap of genetic alteration profiles of plasma and tumors warrants caution in the sole reliance of plasma DNA to identify therapeutically targetable alterations in patients and indicates that analysis of plasma DNA complements, but does not replace, tumor DNA profiling. TRIAL REGISTRATION: Subjects were prospectively enrolled in trial NCT01836640 (registered April 22, 2013).

Ductal Carcinoma in Situ Biomarkers in a Precision Medicine Era: Current and Future Molecular-Based Testing.

Historically, ductal carcinoma in situ (DCIS) of the breast has been managed aggressively with surgery and radiotherapy because of a risk of progression to invasive ductal carcinoma. However, this treatment paradigm has been challenged by overtreatment concerns and evidence that suggests that DCIS can be stratified according to risk of recurrence or risk of progression to invasive disease. Traditional methods of risk stratification include histologic grade and hormone receptor status. Recent technological advancements have enabled an era of precision medicine, where DCIS can be molecularly analyzed by tools, such as next-generation DNA and RNA sequencing, to identify molecular biomarkers for risk stratification. These findings have led to the development of tools such as the Oncotype DX Breast DCIS Score, a gene expression-based assay with the potential to prevent overtreatment in low-risk disease.

Cytokine sensitivity screening highlights BMP4 pathway signaling as a therapeutic opportunity in ER+ breast cancer.

Despite the success of approved systemic therapies for estrogen receptor α (ER)-positive breast cancer, drug resistance remains common. We hypothesized that secreted factors from the human tumor microenvironment could modulate drug resistance. We previously screened a library of 297 recombinant-secreted microenvironmental proteins for the ability to confer resistance to the anti-estrogen fulvestrant in 2 ER+ breast cancer cell lines. Herein, we considered whether factors that enhanced drug sensitivity could be repurposed as therapeutics and provide leads for drug development. Screening data revealed bone morphogenic protein (BMP)4 as a factor that inhibited cell growth and synergized with approved anti-estrogens and cyclin-dependent kinase 4/6 inhibitors (CDK4/6i). BMP4-mediated growth inhibition was dependent on type I receptor activin receptor-like kinase (ALK)3-dependent phosphorylation (P) of mothers against decapentaplegic homolog (SMAD/P-SMAD)1 and 5, which could be reversed by BMP receptor inhibitors and ALK3 knockdown. The primary effect of BMP4 on cell fate was cell-cycle arrest, in which RNA sequencing, immunoblot analysis, and RNA interference revealed to be dependent on p21WAF1/Cip1 upregulation. BMP4 also enhanced sensitivity to approved inhibitors of mammalian target of rapamycin complex 1 and CDK4/6 via ALK3-mediated P-SMAD1/5 and p21 upregulation in anti-estrogen-resistant cells. Patients bearing primary ER+ breast tumors, exhibiting a transcriptomic signature of BMP4 signaling, had improved disease outcome following adjuvant treatment with anti-estrogen therapy, independently of age, tumor grade, and tumor stage. Furthermore, a transcriptomic signature of BMP4 signaling was predictive of an improved biologic response to the CDK4/6i palbociclib, in combination with an aromatase inhibitor in primary tumors. These findings highlight BMP4 and its downstream pathway activation as a therapeutic opportunity in ER+ breast cancer.-Shee, K., Jiang, A., Varn, F. S., Liu, S., Traphagen, N. A., Owens, P., Ma, C. X., Hoog, J., Cheng, C., Golub, T. R., Straussman, R., Miller, T. W. Cytokine sensitivity screening highlights BMP4 pathway signaling as a therapeutic opportunity in ER+ breast cancer.

Molecular genetic profiling reveals novel association between FLT3 mutation and survival in glioma.

INTRODUCTION: Recent molecular characterization of gliomas has uncovered somatic gene variation and DNA methylation changes that are associated with etiology, prognosis, and therapeutic response. Here we describe genomic profiling of gliomas assessed for associations between genetic mutations and patient outcomes, including overall survival (OS) and recurrence-free survival (RFS). METHODS: Mutations in a 50-gene cancer panel, 1p19q co-deletion, and MGMT promoter methylation (MGMT methylation) status were obtained from tumor tissue of 293 glioma patients. Multivariable regression models for overall survival (OS) and recurrence-free survival (RFS) were constructed for MGMT methylation, 1p19q co-deletion, and gene mutations controlling for age, treatment status, and WHO grade. RESULTS: Mutational profiles of gliomas significantly differed based on WHO Grade, such as high prevalence of BRAF V600E, IDH1, and PTEN mutations in WHO Grade I, II/III, and IV tumors, respectively. In multivariate regression analysis, MGMT methylation and IDH1 mutations were significantly associated with improved OS (HR = 0.44, p = 0.0004 and HR = 0.21, p = 0.007, respectively), while FLT3 and TP53 mutations were significantly associated with poorer OS (HR = 19.46, p < 0.0001 and HR = 1.67, p = 0.014, respectively). MGMT methylation and IDH1 mutations were the only significant alterations associated with improved RFS in the model (HR = 0.42, p < 0.0001 and HR = 0.37, p = 0.002, respectively). These factors were then included in a combined model, which significantly exceeded the predictive value of the base model alone (age, surgery, radiation, chemo, grade) (likelihood ratio test OS p = 1.64 × 10-8 and RFS p = 3.80 × 10-7). CONCLUSIONS: This study highlights the genomic landscape of gliomas in a single-institution cohort and identifies a novel association between FLT3 mutation and OS in gliomas.

The curcumin analog HO-3867 selectively kills cancer cells by converting mutant p53 protein to transcriptionally active wildtype p53.

p53 is an important tumor-suppressor protein that is mutated in more than 50% of cancers. Strategies for restoring normal p53 function are complicated by the oncogenic properties of mutant p53 and have not met with clinical success. To counteract mutant p53 activity, a variety of drugs with the potential to reconvert mutant p53 to an active wildtype form have been developed. However, these drugs are associated with various negative effects such as cellular toxicity, nonspecific binding to other proteins, and inability to induce a wildtype p53 response in cancer tissue. Here, we report on the effects of a curcumin analog, HO-3867, on p53 activity in cancer cells from different origins. We found that HO-3867 covalently binds to mutant p53, initiates a wildtype p53-like anticancer genetic response, is exclusively cytotoxic toward cancer cells, and exhibits high anticancer efficacy in tumor models. In conclusion, HO-3867 is a p53 mutant-reactivating drug with high clinical anticancer potential.

Autophagy promotes escape from phosphatidylinositol 3-kinase inhibition in estrogen receptor-positive breast cancer.

Hyperactivation of the PI3K pathway has been implicated in resistance to antiestrogen therapies in estrogen receptor α (ER)-positive breast cancer, prompting the development of therapeutic strategies to inhibit this pathway. Autophagy has tumor-promoting and -suppressing roles and has been broadly implicated in resistance to anticancer therapies, including antiestrogens. Chloroquine (CQ) is an antimalarial and amebicidal drug that inhibits autophagy in mammalian cells and human tumors. Herein, we observed that CQ inhibited proliferation and autophagy in ER+ breast cancer cells. PI3K inhibition with GDC-0941 (pictilisib) induced autophagy. Inhibition of autophagy using CQ or RNA interference potentiated PI3K inhibitor-induced apoptosis. Combined inhibition of PI3K and autophagy effectively induced mitochondrial membrane depolarization, which required the BH3-only proapoptotic proteins Bim and PUMA. Treatment with GDC-0941, CQ, or the combination, significantly suppressed the growth of ER+ breast cancer xenografts in mice. In an antiestrogen-resistant xenograft model, GDC-0941 synergized with CQ to provide partial, but durable, tumor regression. These findings warrant clinical evaluation of therapeutic strategies to target ER, PI3K, and autophagy for the treatment of ER+ breast cancer.-Yang, W., Hosford, S. R., Traphagen, N. A., Shee, K., Demidenko, E., Liu, S., Miller, T. W. Autophagy promotes escape from phosphatidylinositol 3-kinase inhibition in estrogen receptor-positive breast cancer.

Following the crowd: patterns of crowdsourcing on Twitter among urologists.

PURPOSE: To examine patterns of crowdsourcing on the social media platform Twitter among urologists. METHODS: Urologists' public Twitter accounts were reviewed for original posts seeking clinical advice or feedback, and associated reply posts, before and after the 140-character-limit expansion in 2017. Predictors of responses to crowdsourcing requests were determined using multivariable regression. When patient data were posted, we noted whether consent was documented. RESULTS: A total of 276 posts in 23 crowdsourcing requests prior to character-limit expansion were analyzed. Reasons for crowdsourcing included requesting solutions to a clinical dilemma (82 posts, 30%); advice seeking about a surgical plan (77 posts, 28%); surveying colleagues' experiences with a new product (64 posts, 23%); and soliciting feedback about a proposed course of action (53 posts, 19%). Recent completion of training (as a proxy for inexperience) did not appear to disproportionately motivate crowdsourcing; authors' median time in practice was 7 years, and authors practicing for ≤ 7 years initiated 57% of requests. 22 (96%) crowdsourcing requests received ≥ 1 reply. Of 15 requests about a specific patient, eight included imaging, but only one cited patient consent. A second analysis of 184 posts in 17 crowdsourcing requests initiated after character-limit expansion demonstrated significantly more authors replying per request (P = 0.01), but no change in the frequency of patient-specific crowdsourcing or citation of consent. CONCLUSIONS: Urologists are leveraging Twitter for crowdsourcing clinical guidance and experiential knowledge. Nearly all requests were answered, suggesting low barriers to entry for novice users. Even after character-limit expansion, dissemination of potentially identifiable patient data remains a concern.

Tumour micro-environment elicits innate resistance to RAF inhibitors through HGF secretion.

Drug resistance presents a challenge to the treatment of cancer patients. Many studies have focused on cell-autonomous mechanisms of drug resistance. By contrast, we proposed that the tumour micro-environment confers innate resistance to therapy. Here we developed a co-culture system to systematically assay the ability of 23 stromal cell types to influence the innate resistance of 45 cancer cell lines to 35 anticancer drugs. We found that stroma-mediated resistance is common, particularly to targeted agents. We characterized further the stroma-mediated resistance of BRAF-mutant melanoma to RAF inhibitors because most patients with this type of cancer show some degree of innate resistance. Proteomic analysis showed that stromal cell secretion of hepatocyte growth factor (HGF) resulted in activation of the HGF receptor MET, reactivation of the mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3-OH kinase (PI(3)K)-AKT signalling pathways, and immediate resistance to RAF inhibition. Immunohistochemistry experiments confirmed stromal cell expression of HGF in patients with BRAF-mutant melanoma and showed a significant correlation between HGF expression by stromal cells and innate resistance to RAF inhibitor treatment. Dual inhibition of RAF and either HGF or MET resulted in reversal of drug resistance, suggesting RAF plus HGF or MET inhibitory combination therapy as a potential therapeutic strategy for BRAF-mutant melanoma. A similar resistance mechanism was uncovered in a subset of BRAF-mutant colorectal and glioblastoma cell lines. More generally, this study indicates that the systematic dissection of interactions between tumours and their micro-environment can uncover important mechanisms underlying drug resistance.

Readability analysis of online health information about overactive bladder.

AIMS: Despite the prevalence of overactive bladder (OAB) and the widespread accessibility of patient education information on the Internet, the readability of this information and its potential impact on patient decision-making are not known. This study evaluates the readability of OAB material online in the context of website ownership and the Health on the Net standard for information reliability. METHODS: Three Internet search platforms were queried daily with OAB-related keywords for 30 days. Readability analysis was performed using the SMOG test, Dale-Chall readability formula, and Fry readability graph. Websites were stratified by ownership type and Health on the Net certification to compare readability metrics. RESULTS: After 270 total searches, 57 websites were analyzed. Mean SMOG reading grade was 10.7 (SD = 1.6) and 10.1 in an adjusted calculation to reduce overestimation from medical jargon. Mean Dale-Chall score was 9.2 (SD = 0.9), or grade 13-15. Mean Fry graph coordinates (177 syllables, 5.9 sentences) corresponded to grade 15. Only seven sites (12%) were predicted to be readable by the average adult with an eighth-grade reading level. Mean reading grades were not significantly different between academic versus commercial sites and Health on the Net-certified versus non-certified sites. CONCLUSIONS: A large majority of online information about OAB treatment exceeds the reading ability of most adults. Neither websites sponsored by academic institutions nor those certified by the Health on the Net standard have easier readability. The readability of health information online may be distinct from reliability in the context of urological literacy.

The PI3K/mTOR dual inhibitor P7170 demonstrates potent activity against endocrine-sensitive and endocrine-resistant ER+ breast cancer.

Activation of the phosphatidylinositol 3-kinase (PI3K)/AKT/mTOR pathway has been implicated in anti-estrogen resistance in breast cancer. We tested the therapeutic potential of the novel PI3K/mTOR dual inhibitor P7170 in a panel of anti-estrogen-sensitive and anti-estrogen-resistant models of ER+ breast cancer. Estrogen receptor-positive (ER+) breast cancer cells were treated ±P7170. Fresh cores from primary ER+/HER2- tumors from two patients were treated ±P7170 ex vivo. Mice bearing breast cancer xenografts were randomized to treatment with vehicle, fulvestrant, P7170, or combinations, and tumor volumes were measured. Tissues and cells were analyzed for markers of pathway activity, cell viability, and apoptosis. In cell lines, P7170 exhibited IC50 values in the range of 0.9-7 nM and induced apoptosis. P7170 potently inhibited mTOR activity (≤ 25 nM) and inhibited PI3K at higher concentrations (≥ 200 nM). P7170 completely inhibited MCF-7 tumor growth, significantly inhibited growth of fulvestrant-resistant T47D tumors, and suppressed tumor cell proliferation but did not induce apoptosis. While P7170 inhibits PI3K and mTOR in ER+/HER2- human breast cancer cells and tumors ex vivo, in vivo data indicate that the primary mechanism of P7170 anti-tumor action is inhibition of mTOR and cell proliferation. P7170 is a novel agent worthy of further investigation for the treatment of ER+ breast cancer.

Transcriptomic Heterogeneity of Expansile Cribriform and Other Gleason Pattern 4 Prostate Cancer Subtypes.

BACKGROUND: Prostate cancers featuring an expansile cribriform (EC) pattern are associated with worse clinical outcomes following radical prostatectomy (RP). However, studies of the genomic characteristics of Gleason pattern 4 subtypes are limited. OBJECTIVE: To explore transcriptomic characteristics and heterogeneity within Gleason pattern 4 subtypes (fused/poorly formed, glomeruloid, small cribriform, EC/intraductal carcinoma [IDC]) and the association with biochemical recurrence (BCR)-free survival. DESIGN, SETTING, AND PARTICIPANTS: This was a retrospective cohort study including 165 men with grade group 2-4 prostate cancer who underwent RP at a single academic institution (2016-2020) and Decipher testing of the RP specimen. Patients with Gleason pattern 5 were excluded. IDC and EC patterns were grouped. Median follow-up was 2.5 yr after RP for patients without BCR. OUTCOMES MEASUREMENTS AND STATISTICAL ANALYSIS: Prompted by heterogeneity within pattern 4 subtypes identified via exploratory analyses, we investigated transcriptomic consensus clusters using partitioning around medoids and hallmark gene set scores. The primary clinical outcome was BCR, defined as two consecutive prostate-specific antigen measurements >0.2 ng/ml at least 8 wk after RP, or any additional treatment. Multivariable Cox proportional-hazards models were used to determine factors associated with BCR-free survival. RESULTS AND LIMITATIONS: In this cohort, 99/165 patients (60%) had EC and 67 experienced BCR. Exploratory analyses and clustering demonstrated transcriptomic heterogeneity within each Gleason pattern 4 subtype. In the multivariable model controlled for pattern 4 subtype, margin status, Cancer of the Prostate Risk Assessment Post-Surgical score, and Decipher score, a newly identified steroid hormone-driven cluster (hazard ratio 2.35 95% confidence interval 1.01-5.47) was associated with worse BCR-free survival. The study is limited by intermediate follow-up, no validation cohort, and lack of accounting for intratumoral and intraprostatic heterogeneity. CONCLUSIONS: Transcriptomic heterogeneity was present within and across each Gleason pattern 4 subtype, demonstrating there is additional biologic diversity not captured by histologic subtypes. This heterogeneity can be used to develop novel signatures and to classify transcriptomic subtypes, which may help in refining risk stratification following RP to further guide decision-making on adjuvant and salvage treatments. PATIENT SUMMARY: We studied prostatectomy specimens and found that tumors with similar microscopic appearance can have genetic differences that may help to predict outcomes after prostatectomy for prostate cancer. Our results demonstrate that further gene expression analysis of prostate cancer subtypes may improve risk stratification after prostatectomy. Future studies are needed to develop novel gene expression signatures and validate these findings in independent sets of patients.

Voided volume may not impact stone outcomes: Review of a large institutional nephrolithiasis cohort.

Background: Urologic guidelines universally recommend increasing fluid intake for kidney stone prevention. Increased voided volume is thought to help reduce stone recurrence and severity, but supporting evidence is limited. Patients and Methods: Nephrolithiasis outcomes and 24-h urine data for patients from the Registry for Stones of the Kidney and Ureter (ReSKU), a registry of nephrolithiasis patients collected between 2015 and 2020, were retrospectively analysed. Outcome was stone events, either an office visit where a patient reports symptomatic passage of stones or surgery for stone removal. Results: We identified 450 stone patients with 24-h urine and kidney stone outcome data. There was no significant difference in 24-h voided volume between patients with one stone event and patients with two or more stone events. On multivariable logistic regression, after controlling for age, gender, BMI, and 24-h sodium and creatinine per kilogram, no significant associations were found between voided volume and stone events. There was a statistically significant negative correlation noted between voided volume and stone events in calcium oxalate dihydrate stone formers (Spearman R = -0.42, p = 0.04), but not others. Conclusions: Twenty-four-hour voided volume was not associated with stone events in a large institutional cohort, and subset analysis reveals that some stone formers may benefit more from increased voided volume than others; identifying such patients represents a novel precision medicine opportunity.

The Impact of Delayed Radical Prostatectomy on Recurrence Outcomes After Initial Active Surveillance: Results from a Large Institutional Cohort.

BACKGROUND AND OBJECTIVE: Active surveillance (AS) of prostate cancer (PCa) involves regular monitoring for disease progression. The aim is to avoid unnecessary treatment while ensuring appropriate and timely treatment for those whose disease progresses. AS has emerged as the standard of care for low-grade (Gleason grade 1, GG 1) PCa. Opponents are concerned that initial undersampling and delay of definitive management for patients with GG 2 disease may lead to adverse outcomes. We sought to determine whether the timing for definitive management of GG 2 PCa, either upfront or after initial AS, affects recurrence outcomes after radical prostatectomy (RP). METHODS: Participants were diagnosed with cT1-2N0/xM0/x, prostate-specific antigen (PSA) <20 ng/ml, and GG 1-2 PCa between 2000 and 2020 and underwent immediate RP for GG 2 or AS followed by delayed RP on upgrading to GG 2. The outcome was recurrence-free survival (RFS) after surgery, with recurrence defined as either biochemical failure (2 PSA measurements ≥0.2 ng/ml) or a second treatment. Multivariable Cox proportional-hazards regression models were used to calculate associations between the timing for definitive RP and the risk of recurrence, adjusted for age at diagnosis, percentage of positive biopsy cores (PPC), PSA density, PSA before RP, year of diagnosis, surgical margins, genomic risk score, and prostate MRI findings. KEY FINDINGS: Of the 1259 men who met the inclusion criteria, 979 underwent immediate RP after diagnosis of GG 2, 190 underwent RP within 12 mo of upgrading to GG 2 on AS, and 90 men underwent RP >12 mo after upgrading to GG 2. The 5-yr RFS rates were 81% for the immediate RP group, 80% for the delayed RP ≤12 mo, and 70% for the delayed RP >12 mo group (univariate log-rank p = 0.03). Cox multivariable regression demonstrated no difference in RFS outcomes between immediate RP for GG 2 disease and delayed RP after upgrading on AS. PPC (hazard ratio [HR] per 10% increment 1.08, 95% confidence interval [CI] 1.02-1.15; p = 0.01) and PSA before RP (HR 1.06, 95% CI 1.03-1.09; p < 0.01) were significantly associated with the risk of recurrence. CONCLUSIONS AND CLINICAL IMPLICATIONS: PPC and PSA before RP, but not the timing of definitive surgery after upgrade to GG 2, were associated with the risk of PCa recurrence after RP on multivariable analysis. These findings support the safety of AS and delayed definitive therapy for a subset of patients with GG 2 disease. PATIENT SUMMARY: In a large group of 1259 patients with low-grade prostate cancer, we found that delaying surgical treatment after an initial period of active surveillance resulted in no differences in prostate cancer recurrence. Our results support the safety of active surveillance for low-grade prostate cancer.