Estimating and Presenting Hazard Ratios and Absolute Risks from a Cox Model with Complex Non-linear Interactions.

Interaction analysis is a critical component of clinical and public health research and represents a key topic in precision health and medicine. In applied settings, however, interaction assessment is usually limited to the test of a product term in a regression model, and to the presentation of stratified results over levels of additional covariates. Results stratification often relies on categorizing or making linearity assumptions for continuous covariates, with substantial loss of precision and of relevant information. In time-to-event analysis, moreover, interaction assessment is often limited to the multiplicative hazard scale by inclusion of a product terms in a Cox regression model, disregarding the clinically relevant information that are captured by the absolute risk scale. In this paper we present a user-friendly procedure, based on the prediction of individual absolute risks from the Cox model, for the estimation and presentation of interactive effects on both the multiplicative and additive scale in survival analysis. We describe how to flexibly incorporate interactions with continuous covariates, which potentially operate in a non-linear fashion, we provide software material to replicate our procedure, and discuss different approaches to derive confidence intervals. The presented approach will allow clinical and public health researchers assessing complex relationships between multiple covariates as they relate to a clinical endpoint, and providing a more intuitive and precise depiction of the results in applied research papers focusing on interaction and effect stratification.

Prostate Cancer Incidence and Mortality in Men Exposed to α1-Adrenoceptor Antagonists.

BACKGROUND: α1-antagonists are commonly used to treat benign prostatic hyperplasia. Preclinical studies suggest they induce cell death and inhibit tumor growth. This study evaluates the risk of prostate cancer death in men using α1-antagonists. METHODS: A population-based cohort study in Stockholm, Sweden (January 1, 2007 to December 31, 2019) including 451,779 men with a prostate-specific antigen (PSA) test. Study entry was one year after the first PSA test. Men were considered exposed at their second filled prescription. Primary outcome: prostate cancer mortality. Secondary outcomes: all-cause mortality and prostate cancer incidence. Cox proportional hazard regression models were used to calculate adjusted hazard ratios (HRs) and 95% CIs for all outcomes. Inverse probability weighting with marginal structural models accounted for time-dependent confounders. RESULTS: Of 351,297 men in the cohort, 39,856 (11.3%) were exposed to α1-antagonists. Median follow-up for prostate cancer mortality was 8.9 years and median exposure time to α1-antagonists was 4.4 years. There was no evidence of an association between α1-antagonist use and prostate cancer mortality, all-cause mortality, or high-grade prostate cancer. α1-antagonist-use was associated with an increased risk of prostate cancer (HR: 1.11, 95% CI: 1.06-1.17) and low-grade prostate cancer (HR: 1.22, 95% CI: 1.11-1.33). Men treated with α1-antagonists had more frequent PSA testing. CONCLUSIONS: Our findings show no significant association between α1-adrenoceptor antagonist exposure and prostate cancer mortality or high-grade prostate cancer. Although the preclinical evidence indicates a potential chemopreventive effect, this study's findings do not support it.

Biomarker vs MRI-Enhanced Strategies for Prostate Cancer Screening: The STHLM3-MRI Randomized Clinical Trial.

Importance: Prostate cancer guidelines often recommend obtaining magnetic resonance imaging (MRI) before a biopsy, yet MRI access is limited. To date, no randomized clinical trial has compared the use of novel biomarkers for risk estimation vs MRI-based diagnostic approaches for prostate cancer screening. Objective: To evaluate biomarker-based risk estimation (Stockholm3 risk scores or prostate-specific antigen [PSA] levels) with systematic biopsies vs an MRI-enhanced strategy (PSA levels and MRI with systematic and targeted biopsy) for the detection of clinically significant prostate cancer in a screening setting. Design, Setting, and Participants: This open-label randomized clinical trial conducted in Stockholm, Sweden, between April 4, 2018, and December 10, 2020, recruited men aged 50 to 74 years with no history of prostate cancer. Participants underwent blood sampling for PSA and Stockholm3 tests to estimate their risk of clinically significant prostate cancer (Gleason score ≥3 + 4). After the blood tests were performed, participants were randomly assigned in a 2:3 ratio to receive a Stockholm3 test with systematic biopsy (biomarker group) or a PSA test followed by MRI with systematic and targeted biopsy (MRI-enhanced group). Data were analyzed from September 1 to November 5, 2023. Interventions: In the biomarker group, men with a Stockholm3 risk score of 0.15 or higher underwent systematic biopsies. In the MRI-enhanced group, men with a PSA level of 3 ng/mL or higher had an MRI and those with a Prostate Imaging-Reporting and Data System (PI-RADS) score of 3 or higher (range: 1-5, with higher scores indicating a higher likelihood of clinically significant prostate cancer) underwent targeted and systematic biopsies. Main Outcomes and Measures: Primary outcome was detection of clinically significant prostate cancer (Gleason score ≥3 + 4). Secondary outcomes included detection of clinically insignificant cancer (Gleason score ≤6) and the number of biopsy procedures performed. Results: Of 12 743 male participants (median [IQR] age, 61 [55-67] years), 5134 were assigned to the biomarker group and 7609 to the MRI-enhanced group. In the biomarker group, 8.0% of men (413) had Stockholm3 risk scores of 0.15 or higher and were referred for systematic biopsies. In the MRI-enhanced group, 12.2% of men (929) had a PSA level of 3 ng/mL or higher and were referred for MRI with biopsies if they had a PI-RADS score of 3 or higher. Detection rates of clinically significant prostate cancer were comparable between the 2 groups: 2.3% in the biomarker group and 2.5% in the MRI-enhanced group (relative proportion, 0.92; 95% CI, 0.73-1.15). More biopsies were performed in the biomarker group than in the MRI-enhanced group (326 of 5134 [6.3%] vs 338 of 7609 [4.4%]; relative proportion, 1.43 [95% CI, 1.23-1.66]), and more indolent prostate cancers were detected (61 [1.2%] vs 41 [0.5%]; relative proportion, 2.21 [95% CI, 1.49-3.27]). Conclusions and Relevance: Findings of this randomized clinical trial indicate that combining a Stockholm3 test with systematic biopsies is comparable with MRI-based screening with PSA levels and systematic and targeted biopsies for detection of clinically significant prostate cancer, but this approach resulted in more biopsies as well as detection of a greater number of indolent cancers. In regions where access to MRI is lacking, the Stockholm3 test can aid in selecting patients for systematic prostate biopsy. Trial Registration: ClinicalTrials.gov Identifier: NCT03377881.

Repeated Prostate Cancer Screening Using Prostate-Specific Antigen Testing and Magnetic Resonance Imaging: A Secondary Analysis of the STHLM3-MRI Randomized Clinical Trial.

Importance: Magnetic resonance imaging (MRI) has been proposed to enhance the benefit-to-harm ratio of prostate cancer screening, but data on repeated screening outcomes are lacking. Objective: To describe outcomes of prostate-specific antigen (PSA)-based screening with MRI and prostate biopsies at repeat screening. Design, Setting, and Participants: This secondary analysis examined the population-based, screen-by-invitation STHLM3-MRI randomized clinical trial, which recruited Swedish men aged 50 to 74 years. Men were eligible for repeat screening at 2 to 3 years if they had PSA levels of 1.5 ng/mL or greater at trial inclusion, were randomized to the MRI-targeted group (including screening using biomarkers and MRI), and were not diagnosed with prostate cancer after the first screening round. Repeat screening was performed between November 10, 2021, and February 20, 2023. Data analysis was performed between May and August 2023. Intervention: Participants underwent blood sampling, including PSA testing. A biparametric MRI scan was performed if PSA levels were 3 ng/mL or greater, and men with lesions with a Prostate Imaging-Reporting and Data System (PI-RADS) score of 3 or greater were referred for targeted and systematic biopsies. Main Outcomes and Measures: The primary outcome was clinically significant prostate cancer (Gleason score of ≥3 + 4). Secondary outcomes included the proportion of men with clinically insignificant cancer (Gleason score of 6), the number of elevated PSA tests, MRI scans, and biopsy procedures. Results: Of 7609 men from the first screening round, 2078 (27.3%) were eligible for and were invited for rescreening. Among the invitees, 1500 (72.2%) participated. Their median age was 67 (IQR, 61-72) years. Of 1094 men with PSA levels between 1.5 and 2.9 ng/mL in the first screening round, 326 (29.8%) had levels of 3 ng/mL or greater in the second round. Overall, 667 men (44.5%) had PSA levels of 3 ng/mL or greater: 617 underwent MRI (92.5%), revealing 51 (7.6%) with equivocal lesions (PI-RADS score of 3) and 33 (4.9%) with suspicious lesions (PI-RADS score of ≥4). Only 10 of 383 men (2.6%) with a prior negative MRI result had a lesion with a PI-RADS score of 4 or greater. Among the 1500 rescreened men, 48 (3.2%) had a Gleason score of 3 + 4 or greater, including 19 (1.3%) with a score of 4 + 3 or greater and 11 (0.7%) with a score of 6. Conclusions and Relevance: In this secondary analysis of the STHLM3-MRI randomized clinical trial, cancer detection during the second screening round in biennial PSA and MRI-based prostate cancer screening was limited, and the detection of low-grade tumors remained low. A substantial proportion of men exhibited elevated PSA levels during rescreening, and a considerable portion of MRI scans performed lacked lesions suggestive of cancer. Future studies should explore strategies to reduce MRI-related resource use. Trial Registration: ClinicalTrials.gov Identifier: NCT03377881.

Side effects of low-dose tamoxifen: results from a six-armed randomised controlled trial in healthy women.

BACKGROUND: Adherence to adjuvant tamoxifen therapy is suboptimal, and acceptance of tamoxifen for primary prevention is poor. Published results indicate effect of low-dose tamoxifen therapy. Using questionnaire data from a randomised controlled trial, we describe side effects of standard and low-dose tamoxifen in healthy women. METHODS: In the KARISMA trial, 1440 healthy women were randomised to 6 months of daily intake of 20, 10, 5, 2.5, 1 mg of tamoxifen or placebo. Participants completed a 48-item, five-graded Likert score symptom questionnaire at baseline and follow-up. Linear regression models were used to identify significant changes in severity levels across doses and by menopausal status. RESULTS: Out of 48 predefined symptoms, five were associated with tamoxifen exposure (hot flashes, night sweats, cold sweats, vaginal discharge and muscle cramps). When comparing these side effects in premenopausal women randomised to low doses (2.5, 5 mg) versus high doses (10, 20 mg), the mean change was 34% lower in the low-dose group. No dose-dependent difference was seen in postmenopausal women. CONCLUSIONS: Symptoms related to tamoxifen therapy are influenced by menopausal status. Low-dose tamoxifen, in contrast to high-dose, was associated with less pronounced side effects, a finding restricted to premenopausal women. Our findings give new insights which may influence future dosing strategies of tamoxifen in both the adjuvant and preventive settings. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT03346200.

Prostate Cancer IRE Study (PRIS): A Randomized Controlled Trial Comparing Focal Therapy to Radical Treatment in Localized Prostate Cancer.

The aim of focal treatments (FTs) in prostate cancer (PCa) is to treat lesions while preserving surrounding benign tissue and anatomic structures. Irreversible electroporation (IRE) is a nonthermal technique that uses high-voltage electric pulses to increase membrane permeability and induce membrane disruption in cells, which potentially causes less damage to the surrounding tissue in comparison to other ablative techniques. We summarize the study protocol for the Prostate Cancer IRE Study (PRIS), which involves two parallel randomized controlled trials comparing IRE with (1) robot-assisted radical prostatectomy (RARP) or (2) radiotherapy in men with newly diagnosed intermediate-risk PCa (NCT05513443). To reduce the number of patients for inclusion and the study duration, the primary outcomes are functional outcomes: urinary incontinence in study 1 and irritative urinary symptoms in study 2. Providing evidence of the lower impact of IRE on functional outcomes will lay a foundation for the design of future multicenter studies with an oncological outcome as the primary endpoint. Erectile function, quality of life, treatment failure, adverse events, and cost effectiveness will be evaluated as secondary objectives. Patients diagnosed with Gleason score 3 + 4 or 4 + 3 PCa from a single lesion visible on magnetic resonance imaging (MRI) without any Gleason grade 4 or higher in systematic biopsies outside of the target (unifocal significant disease), aged ≥40 yr, with no established extraprostatic extension on multiparametric MRI, a lesion volume of <1.5 cm3, prostate-specific antigen <20 ng/ml, and stage ≤T2b are eligible for inclusion. The study plan is to recruit 184 men.

Cost-effectiveness of Prostate Cancer Screening Using Magnetic Resonance Imaging or Standard Biopsy Based on the STHLM3-MRI Study.

Importance: The combination of prostate-specific antigen (PSA) testing with magnetic resonance imaging (MRI) for prostate cancer detection has rarely been evaluated in a screening context. The STHLM3-MRI screening-by-invitation study (NCT03377881) has reported the benefits of using MRI with subsequent combined targeted and standard biopsies compared with using standard biopsies alone. Objective: To investigate the cost-effectiveness of prostate cancer screening using MRI with combined targeted and standard biopsies compared with standard biopsies alone among men aged 55 to 69 years in Sweden, based on evidence from the STHLM3-MRI study. Design, Setting, and Participants: This economic evaluation study was conducted from a lifetime health care perspective using a microsimulation model to evaluate no screening and screening strategies among adult men in Sweden. Men aged 55 to 69 years in Sweden were simulated for no screening and screening strategies. Input parameters were obtained from the STHLM3-MRI study and recent reviews. One-way and probabilistic sensitivity analyses were performed in May 2022. Interventions: No screening, quadrennial PSA screening using standard biopsies alone, and MRI-based screening using combined targeted and standard biopsies. Main Outcomes and Measures: The number of tests, incidence, deaths, costs, quality-adjusted life-years (QALY), and incremental cost-effectiveness ratios (ICERs) were estimated. Results: A total 603 men were randomized to the standard arm, 165 of these participants (27.4%) did not undergo standard biopsy; 929 men were randomized to the experimental arm, 111 (11.9%) of whom did undergo MRI or any biopsy. Compared with no screening, the screening strategies were associated with reduced lifetime prostate cancer-related deaths by 6% to 9%. Screening with MRI and the combined biopsies resulted in an ICER of US $53 736, which is classified as a moderate cost per QALY gained in Sweden. Relative to screening with standard biopsies alone, MRI-based screening reduced the number of both lifetime biopsies and overdiagnosis by approximately 50% and had a high probability of being cost-effective than the traditional PSA screening. Conclusions and Relevance: For prostate cancer screening, this economic evaluation study found that PSA testing followed by MRI with subsequent combined targeted and standard biopsies had a high probability to be more cost-effective compared with the traditional screening pathway using PSA and standard biopsy. MRI-based screening may be considered for early detection of prostate cancer in Sweden.

I-SPY COVID adaptive platform trial for COVID-19 acute respiratory failure: rationale, design and operations.

INTRODUCTION: The COVID-19 pandemic brought an urgent need to discover novel effective therapeutics for patients hospitalised with severe COVID-19. The Investigation of Serial studies to Predict Your Therapeutic Response with Imaging And moLecular Analysis (ISPY COVID-19 trial) was designed and implemented in early 2020 to evaluate investigational agents rapidly and simultaneously on a phase 2 adaptive platform. This manuscript outlines the design, rationale, implementation and challenges of the ISPY COVID-19 trial during the first phase of trial activity from April 2020 until December 2021. METHODS AND ANALYSIS: The ISPY COVID-19 Trial is a multicentre open-label phase 2 platform trial in the USA designed to evaluate therapeutics that may have a large effect on improving outcomes from severe COVID-19. The ISPY COVID-19 Trial network includes academic and community hospitals with significant geographical diversity across the country. Enrolled patients are randomised to receive one of up to four investigational agents or a control and are evaluated for a family of two primary outcomes-time to recovery and mortality. The statistical design uses a Bayesian model with 'stopping' and 'graduation' criteria designed to efficiently discard ineffective therapies and graduate promising agents for definitive efficacy trials. Each investigational agent arm enrols to a maximum of 125 patients per arm and is compared with concurrent controls. As of December 2021, 11 investigational agent arms had been activated, and 8 arms were complete. Enrolment and adaptation of the trial design are ongoing. ETHICS AND DISSEMINATION: ISPY COVID-19 operates under a central institutional review board via Wake Forest School of Medicine IRB00066805. Data generated from this trial will be reported in peer-reviewed medical journals. TRIAL REGISTRATION NUMBER: NCT04488081.

Association of 5α-Reductase Inhibitors With Prostate Cancer Mortality.

Importance: There is evidence that 5α-reductase inhibitors (5-ARIs), a standard treatment of benign prostate hyperplasia, are associated with a decrease in the incidence of prostate cancer (PCa). However, studies to date have had conflicting results regarding the association with prostate cancer mortality (PCM). Objective: To evaluate the association of treatment with 5-ARIs with PCM in men without a prior diagnosis of PCa. Design, Setting, and Participants: This population-based cohort study was conducted in Stockholm, Sweden, between January 1, 2007, and December 31, 2018, and included 429 977 men with a prostate-specific antigen (PSA) test within the study period. Study entry was set to 1 year after the first PSA test. Data were analyzed from September 2021 to December 2021. Exposures: After their initial PSA test, men with 2 or more newly dispensed prescriptions of 5-ARI, finasteride, or dutasteride were considered 5-ARI users (n = 26 190). Main Outcomes and Measures: Primary outcome was PCM. Cox proportional hazards regression models were used to calculate multivariable-adjusted hazard ratios (HRs) and 95% CIs for all-cause mortality and PCM. Results: The study cohort included 349 152 men. The median (IQR) age for those with 2 or more filled prescriptions of 5-ARI was 66 (61-73) years and 57 (50-64) years for those without. The median follow-up time was 8.2 (IQR, 4.9-10) years with 2 257 619 person-years for the unexposed group and 124 008 person-years for the exposed group. The median exposure to treatment with 5-ARI was 4.5 (IQR, 2.1-7.4) years. During follow-up, 35 767 men (8.3%) died, with 852 deaths associated with PCa. The adjusted multivariable survival analysis showed a lower risk of PCM in the 5-ARI group with longer exposure times (0.1-2.0 years: adjusted HR, 0.89; 95% CI, 0.64-1.25; >8 years: adjusted HR, 0.44; 95% CI, 0.27-0.74). No statistically significant differences were seen in all-cause mortality between the exposed and unexposed group. Men treated with 5-ARIs underwent more PSA tests and biopsies per year than the unexposed group (median of 0.63 vs 0.33 and 0.22 vs 0.12, respectively). Conclusions and Relevance: The results of this cohort study suggest that there was no association between treatment with 5-ARI and increased PCM in a large population-based cohort of men without a previous PCa diagnosis. Additionally, a time-dependent association was seen with decreased risk of PCM with longer 5-ARI treatment. Further research is needed to determine whether the differences are because of intrinsic drug effects or PCa testing differences.

Clinical Trial Protocol for ProBio: An Outcome-adaptive and Randomised Multiarm Biomarker-driven Study in Patients with Metastatic Prostate Cancer.

ProBio is an outcome-adaptive, multiarm, multiple-assignment randomised, biomarker-driven platform trial in men with metastatic castration-resistant prostate cancer. Here we describe the amended clinical protocol, focusing on expansion of the trial to include patients with de novo metastatic hormone-sensitive prostate cancer.

Cost-Effectiveness of the Stockholm3 Test and Magnetic Resonance Imaging in Prostate Cancer Screening: A Microsimulation Study.

BACKGROUND: Stockholm3 is a risk model that combines the prostate-specific antigen (PSA) test, other plasma protein biomarkers, single nucleotide polymorphisms, and clinical variables. The STHLM3-MRI study (NCT03377881) found that the Stockholm3 test with magnetic resonance imaging (MRI) and combined targeted and systematic biopsies maintained the sensitivity for clinically significant cancers, and reduced the number of benign biopsies and clinically insignificant cancers. OBJECTIVE: To assess the cost-effectiveness of MRI-based screening for prostate cancer using either Stockholm3 as a reflex test or PSA alone. DESIGN, SETTING, AND PARTICIPANTS: A cost-utility analysis was performed from a lifetime societal perspective using a microsimulation model for men aged 55-69 yr in Sweden. Test characteristics were estimated from the STHLM3-MRI study. INTERVENTION: No screening and three quadrennial screening strategies, including either PSA ≥3 ng/ml or Stockholm3 with reflex test thresholds of PSA ≥1.5 or 2 ng/ml as criteria for referral to MRI, were performed, and those who were MRI positive had combined targeted and systematic biopsies. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Predictions included the number of tests, cancer incidence and mortality, costs, and quality-adjusted life-years. Uncertainties in key parameters were assessed using sensitivity analyses. RESULTS AND LIMITATIONS: Compared with no screening, the screening strategies were predicted to reduce prostate cancer deaths by 7-9% across a lifetime. The use of Stockholm3 with PSA ≥2 ng/ml resulted in a 60% reduction in MRI compared with screening using PSA. This Stockholm3 strategy was cost-effective with a probability of 70% at a cost-effectiveness threshold of €47 218 (500 000 Swedish Kronor). As a potential limitation, the economic perspective was specific to Sweden. CONCLUSIONS: Screening with the Stockholm3 test at a reflex threshold of PSA ≥2 ng/ml and MRI was predicted to be cost-effective in Sweden. PATIENT SUMMARY: The Stockholm3 test with image-based screening may reduce screening-related harms and costs, while maintaining the health benefits from early detection of prostate cancer.

Prostate cancer screening using a combination of risk-prediction, MRI, and targeted prostate biopsies (STHLM3-MRI): a prospective, population-based, randomised, open-label, non-inferiority trial.

BACKGROUND: Screening for prostate cancer using prostate-specific antigen (PSA) reduces prostate cancer mortality but can lead to adverse outcomes. We aimed to compare a traditional screening approach with a diagnostic strategy of blood-based risk prediction combined with MRI-targeted biopsies. METHODS: We did a prospective, population-based, randomised, open-label, non-inferiority trial (STHLM3-MRI) in Stockholm county, Sweden. Men aged 50-74 years were randomly selected by Statistics Sweden and invited by mail to participate in screening; those with an elevated risk of prostate cancer, defined as either a PSA of 3 ng/mL or higher or a Stockholm3 score of 0·11 or higher were eligible for randomisation. Men with a previous prostate cancer diagnosis, who had undergone a prostate biopsy within 60 days before the invitation to participate, with a contraindication for MRI, or with severe illness were excluded. Eligible participants were randomly assigned (2:3) using computer-generated blocks of five, stratified by clinically significant prostate cancer risk, to receive either systematic prostate biopsies (standard group) or biparametric MRI followed by MRI-targeted and systematic biopsy in MRI-positive participants (experimental group). The primary outcome was the detection of clinically significant prostate cancer at prostate biopsy, defined as a Gleason score of 3 + 4 or higher. We used a margin of 0·78 to assess non-inferiority for the primary outcome. Key secondary outcome measures included the proportion of men with clinically insignificant prostate cancer (defined as a Gleason score of 3 + 3), and the number of any prostate MRI and biopsy procedures done. We did two comparisons: Stockholm3 (using scores of 0·11 and 0·15 as cutoffs) versus PSA in the experimental group (paired analyses) and PSA plus standard biopsy versus Stockholm3 plus MRI-targeted and systematic biopsy (unpaired, randomised analyses). All analyses were intention to treat. This study is registered with ClinicalTrials.gov, NCT03377881. FINDINGS: Between Feb 5, 2018, and March 4, 2020, 49 118 men were invited to participate, of whom 12 750 were enrolled and provided blood specimens, and 2293 with elevated risk were randomly assigned to the experimental group (n=1372) or the standard group (n=921). The area under the receiver-operating characteristic curve for detection of clinically significant prostate cancer was 0·76 (95% CI 0·72-0·80) for Stockholm3 and 0·60 (0·54-0·65) for PSA. In the experimental group, a Stockholm3 of 0·11 or higher was non-inferior to a PSA of 3 ng/mL or higher for detection of clinically significant prostate cancer (227 vs 192; relative proportion [RP] 1·18 [95% CI 1·09-1·28], p<0·0001 for non-inferiority), and also detected a similar number of low-grade prostate cancers (50 vs 41; 1·22 [0·96-1·55], p=0·053 for superiority) and was associated with more MRIs and biopsies. Compared with PSA of 3 ng/mL or higher, a Stockholm3 of 0·15 or higher provided identical sensitivity to detect clinically significant cancer, and led to fewer MRI procedures (545 vs 846; 0·64 [0·55-0·82]) and fewer biopsy procedures (311 vs 338; 0·92 (0·86-1·03). Compared with screening using PSA and systematic biopsies, a Stockholm3 of 0·11 or higher combined with MRI-targeted and systematic biopsies was associated with higher detection of clinically significant cancers (227 [3·0%] men tested vs 106 [2·1%] men tested; RP 1·44 [95% CI 1·15-1·81]), lower detection of low-grade cancers (50 [0·7%] vs 73 [1·4%]; 0·46 [0·32-0·66]), and led to fewer biopsy procedures. Patients randomly assigned to the experimental group had a lower incidence of prescription of antibiotics for infection (25 [1·8%] of 1372 vs 41 [4·4%] of 921; p=0·0002) and a lower incidence of admission to hospital (16 [1·2%] vs 31 [3·4%]; p=0·0003) than those in the standard group. INTERPRETATION: The Stockholm3 test can inform risk stratification before MRI and targeted biopsies in prostate cancer screening. Combining the Stockholm3 test with an MRI-targeted biopsy approach for prostate cancer screening decreases overdetection while maintaining the ability to detect clinically significant cancer. FUNDING: The Swedish Cancer Society, the Swedish Research Council, and Stockholm City Council.

MRI-Targeted or Standard Biopsy in Prostate Cancer Screening.

BACKGROUND: High rates of overdiagnosis are a critical barrier to organized prostate cancer screening. Magnetic resonance imaging (MRI) with targeted biopsy has shown the potential to address this challenge, but the implications of its use in the context of organized prostate cancer screening are unknown. METHODS: We conducted a population-based noninferiority trial of prostate cancer screening in which men 50 to 74 years of age from the general population were invited by mail to participate; participants with prostate-specific antigen (PSA) levels of 3 ng per milliliter or higher were randomly assigned, in a 2:3 ratio, to undergo a standard biopsy (standard biopsy group) or to undergo MRI, with targeted and standard biopsy if the MRI results suggested prostate cancer (experimental biopsy group). The primary outcome was the proportion of men in the intention-to-treat population in whom clinically significant cancer (Gleason score ≥7) was diagnosed. A key secondary outcome was the detection of clinically insignificant cancers (Gleason score 6). RESULTS: Of 12,750 men enrolled, 1532 had PSA levels of 3 ng per milliliter or higher and were randomly assigned to undergo biopsy: 603 were assigned to the standard biopsy group and 929 to the experimental biopsy group. In the intention-to-treat analysis, clinically significant cancer was diagnosed in 192 men (21%) in the experimental biopsy group, as compared with 106 men (18%) in the standard biopsy group (difference, 3 percentage points; 95% confidence interval [CI], -1 to 7; P<0.001 for noninferiority). The percentage of clinically insignificant cancers was lower in the experimental biopsy group than in the standard biopsy group (4% [41 participants] vs. 12% [73 participants]; difference, -8 percentage points; 95% CI, -11 to -5). CONCLUSIONS: MRI with targeted and standard biopsy in men with MRI results suggestive of prostate cancer was noninferior to standard biopsy for detecting clinically significant prostate cancer in a population-based screening-by-invitation trial and resulted in less detection of clinically insignificant cancer. (Funded by the Swedish Research Council and others; STHLM3-MRI ClinicalTrials.gov number, NCT03377881.).

Modeling the probability of occurrence of events.

This paper introduces the event-probability function, a measure of occurrence of an event of interest over time, defined as the instantaneous probability of an event at a given time point conditional on having survived until that point. Unlike the hazard function, the event-probability function is a proper probability. This paper describes properties and interpretation of the event-probability function, presents its connection with other popular functions, such as the hazard and survival functions, proposes practical flexible proportional-odds models for estimating conditional event-probabilities given covariates with possibly censored and truncated observations, discusses the theoretical and computational aspects of parameter estimation, and applies the proposed models for assessing mortality in patients with metastatic renal carcinoma from a randomized clinical trial.

Low-Dose Tamoxifen for Mammographic Density Reduction: A Randomized Controlled Trial.

PURPOSE: Tamoxifen prevents breast cancer in high-risk women and reduces mortality in the adjuvant setting. Mammographic density change is a proxy for tamoxifen therapy response. We tested whether lower doses of tamoxifen were noninferior to reduce mammographic density and associated with fewer symptoms. PATIENTS AND METHODS: Women, 40-74 years of age, participating in the Swedish mammography screening program were invited to the 6-month double-blind six-arm randomized placebo-controlled noninferiority dose-determination KARISMA phase II trial stratified by menopausal status (EudraCT 2016-000882-22). In all, 1,439 women were accrued with 1,230 participants accessible for intention-to-treat analysis. The primary outcome was proportion of women treated with placebo, 1, 2.5, 5, and 10 mg whose mammographic density decreased at least as much as the median reduction in the 20 mg arm. The noninferior margin was 17%. Secondary outcome was reduction of symptoms. Post hoc analyses were performed by menopausal status. Per-protocol population and full population were analyzed in sensitivity analysis. RESULTS: The 1,439 participants, 566 and 873 pre- and postmenopausal women, respectively, were recruited between October 1, 2016, and September 30, 2019. The participants had noninferior mammographic density reduction following 2.5, 5, and 10 mg tamoxifen compared with the median 10.1% decrease observed in the 20 mg group, a reduction confined to premenopausal women. Severe vasomotor symptoms (hot flashes, cold sweats, and night sweats) were reduced by approximately 50% in the 2.5, 5, and 10 mg groups compared with the 20 mg group. CONCLUSION: Premenopausal women showed noninferior magnitude of breast density decrease at 2.5 mg of tamoxifen, but fewer side effects compared with the standard dose of 20 mg. Future studies should test whether 2.5 mg of tamoxifen reduces the risk of primary breast cancer.

Opioid Use After Intensive Care: A Nationwide Cohort Study.

OBJECTIVE: To describe opioid use after ICU admission, identify factors associated with chronic opioid use after critical care, and determine if chronic opioid use is associated with an increased risk of death. DESIGN: Retrospective cohort study. SETTING: Sweden including all registered ICU admissions between 2010 and 2018. PATIENTS: Adults surviving the first two quarters after ICU admission were eligible for inclusion. A total of 265,496 patients were screened and 61,094 were ineligible. INTERVENTIONS: Admission to intensive care. MEASUREMENTS AND MAIN RESULTS: Among 204,402 individuals included in the cohort, 22,138 developed chronic opioid use following critical care. Mean opioid consumption peaked after admission followed by a continuous decline without returning to baseline during follow-up of 24 months. Factors associated with chronic opioid use included high age, female sex, presence of comorbidities, preadmission opioid use, and ICU length of stay greater than 2 days. Adjusted hazard ratio for death 6-18 months after admission for chronic opioid users was 1.7 (95% CI, 1.6-1.7; p < 0.001). In the subset of patients not using opioids prior to admission, similar findings were noted. CONCLUSIONS: Mean opioid consumption is increased 24 months after ICU admission despite the lack of evidence for long-term opioid treatment. Given the high number of ICU entries and risk of excess mortality for chronic users, preventing opioid misuse is important when improving long-term outcomes after critical care.

Ethnic variation in prostate cancer detection: a feasibility study for use of the Stockholm3 test in a multiethnic U.S. cohort.

BACKGROUND: The Stockholm3 test improves Gleason Grade Group ≥2 (GG ≥ 2) prostate cancer (PC) detection, however it has not been evaluated in an American cohort where clinical practice patterns and ethnicity differ. We aimed to identify subgroups within a Stockholm population with PC risk profiles matching American ethnicity-specific subgroups and compare the detection of PC and describe Stockholm3 performance within these subgroups. METHODS: All men age 49-70 years presenting for prostate biopsies were evaluated at UIC from 2016 to 2019, as well as men in Stockholm from 2012 to 2014 in the STHLM3 study. Propensity scores (PS) were estimated for each person using logistic regression for age, PSA, prostate volume, family history of PC, 5-alpha reductase inhibitor use, and prior biopsy. 3:1 PS matching was performed for Stockholm to Chicago ethnicity-specific cohorts and odds ratios (OR) were computed to compare detection of GG ≥ 2 PC between groups. RESULTS: 504 Chicago men and 6980 Stockholm men were included. In African American (AA) men, 51% had GG ≥ 2 PC detected, while in risk-matched Stockholm men, 34% had GG ≥ 2 PC detected (OR: 2.1, p < 0.001). There was no statistical difference in GG ≥ 2 PC detected when matching Stockholm men to non-Hispanic Caucasian men (31% vs. 24%, OR: 0.7, p = 0.30) or Hispanic Caucasian men (31% vs. 27%, OR: 1.2, p = 0.42). The AUC for the Stockholm3 test of the matched Stockholm cohorts for AA, non-Hispanic Caucasian, and Hispanic Caucasian men was 0.85, 0.89, and 0.90, respectively. CONCLUSIONS: Using statistical techniques to simulate a multi-ethnic Chicago cohort within the STHLM3 population, we found an excess risk of GG ≥ 2 PC among AA men. Our hypothesis that the Stockholm3 may have good predictive value in a multiethnic cohort is strengthened, and that recalibration to at least AA men seems likely to be needed to obtain well-calibrated predictions.

Is rheumatoid arthritis a risk factor for acute coronary syndrome also among individuals at elevated risk, such as individuals presenting with acute chest pain?

BACKGROUND: Patients with rheumatoid arthritis (RA) are, on average, at increased risk of acute coronary syndrome (ACS) compared to the general population, but it remains unknown whether RA remains an ACS risk factor also in settings where the ACS risk is already high elevated, such as among individuals presenting to the emergency department (ED) with chest pain. METHODS AND RESULTS: We included 49 283 individuals (514 (1.0%) had RA) presenting with chest pain at the four hospital EDs in Stockholm, Sweden, 2013-2016 in a cohort study. Information on exposure (RA), outcome (ACS) and comorbidities was provided through national registers. The association between RA and ACS was assessed, overall and by levels of high-sensitivity cardiac troponin T (hs-cTnT) and number of ACS risk factors, using logistic regression models adjusted for age, sex, hospital, calendar year and cardiovascular risk factors. ACS was more common in patients with (8.2%) than without (4.6%) RA, adjusted OR =1.4, 95% CI 1.0 to 2.0. This association was particularly strong in individuals with initial hs-cTnT levels between 5 and 14 ng/L, or no additional ACS risk factors (adjusted ORs above 2), but no longer detectable in those with hs-cTnT >14 ng/L or with three or more additional ACS risk factors. CONCLUSION: RA is a risk factor for ACS also among patients at the ED with chest pain. This association is not explained by traditional ACS risk factors, and most pronounced in patients with normal hs-cTnT and few other ACS risk factors, prompting particular ACS vigilance in this RA patient group.