Mortality risk in patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the leading inheritable cause of end-stage renal disease (ESRD). Mortality data specific to patients with ADPKD is currently lacking; thus, the aim of this study was to estimate mortality in patients with ADPKD. METHODS: We analyzed data from the United States Renal Data System (USRDS) for patients with ADPKD available during the study period of 01/01/2014-12/31/2016, which included a cohort of patients with non-ESRD chronic kidney disease (CKD) and a cohort of patients with ESRD. Mortality rates with 95% confidence intervals (CIs) were calculated overall and by age group, sex, and race for the full dataset and for a subset of patients aged ≥ 65 years. Adjusted mortality hazard ratios (HRs) were calculated using Cox regression modeling by age group, sex, race, and CKD stage (i.e., non-ESRD CKD stages 1-5) or ESRD treatment (i.e., dialysis and transplant). RESULTS: A total of 1,936 patients with ADPKD and non-ESRD CKD and 37,461 patients with ADPKD and ESRD were included in the analysis. Age-adjusted mortality was 18.4 deaths per 1,000 patient-years in the non-ESRD CKD cohort and 37.4 deaths per 1,000 patient-years in the ESRD cohort. As expected, among the non-ESRD CKD cohort, patients in CKD stages 4 and 5 had a higher risk of death than patients in stage 3 (HR = 1.59 for stage 4 and HR = 2.71 for stage 5). Among the ESRD cohort, patients receiving dialysis were more likely to experience death than patients who received transplant (HR = 2.36). Age-adjusted mortality among patients aged ≥ 65 years in the non-ESRD CKD cohort was highest for Black patients (82.7 deaths per 1,000 patient-years), whereas age-adjusted mortality among patients aged ≥ 65 years in the ESRD cohort was highest for White patients (136.1 deaths per 1,000 patient-years). CONCLUSIONS: Mortality rates specific to patients aged ≥ 65 years suggest racial differences in mortality among these patients in both non-ESRD CKD and ESRD cohorts. These data fill an important knowledge gap in mortality estimates for patients with ADPKD in the United States.

A post hoc analysis of Projected Retained Ability Scores (PRAS) for the longitudinal assessment of cognitive functioning in patients with neuronopathic mucopolysaccharidosis II receiving intrathecal idursulfase-IT.

BACKGROUND: Norm-based scores used to assess cognitive ability have clinical value when describing functioning of patients with neuronopathic disorders compared with unaffected, same-age peers. However, they have limitations when used to assess change in cognitive ability between two timepoints, especially in children with severe cognitive decline. Calculation of Projected Retained Ability Scores (PRAS) is a novel method developed to characterize absolute change in norm-based ability test scores. In this analysis, PRAS were calculated post hoc for children with mucopolysaccharidosis II (MPS II; Hunter syndrome) and early cognitive impairment in a 52-week phase 2/3 randomized controlled trial (RCT) and its extension study of intrathecal idursulfase (idursulfase-IT). Patients completing the first year of the extension after receiving idursulfase-IT in the RCT and extension (n = 32 of 34 enrolled) or the extension only (n = 15 of 15 enrolled) were categorized according to changes in Differential Ability Scales, Second Edition, General Conceptual Ability (DAS-II GCA) scores and PRAS at 1 and 2 years. Analyses were conducted in the overall population and a subpopulation aged < 6 years at baseline (idursulfase-IT in the RCT and extension [n = 27] and extension only [n = 12]). RESULTS: PRAS methodology differentiated patients with decreases in DAS-II GCA scores into three separate categories reflecting below-average cognitive growth rates, plateauing cognitive development, and deteriorating cognitive functioning. After 1 year in the RCT, 72.4% of patients who initiated idursulfase-IT had above-average or average cognitive growth rates in DAS-II GCA scores compared with 53.3% of those who did not receive idursulfase-IT; 6.9% versus 20.0% experienced deteriorating cognitive functioning. Similar results were seen in children aged < 6 years: 76% (idursulfase-IT group) versus 50% (no idursulfase-IT) had above-average or average cognitive growth rates in DAS-II GCA scores; 4% versus 17% had deteriorating cognitive functioning. The difference in the distributions of cognitive categories at 1 year in children aged < 6 years was significant (p = 0.048). At 2 years, the proportions of patients in different cognitive categories were more similar between treatment groups. CONCLUSIONS: PRAS methodology may help to differentiate changes in cognitive development in MPS II, and therefore may represent a valuable addition to existing approaches for interpreting changes in cognitive scores over time. TRIAL REGISTRATION: ClinicalTrials.gov NCT02055118 (registration date: 4 February 2014) and NCT02412787 (registration date: 9 April 2015).

The Zero-Price Conundrum: Exploration of Scenarios Where a Clinically Effective New Drug Might Not Be Cost-Effective at Zero Price.

OBJECTIVES: The zero-price conundrum occurs when a clinically effective drug can justify no greater than a price of zero based on cost-effectiveness criteria from a health system perspective. This is relevant for health systems that require evidence of cost-effectiveness, in addition to safety and efficacy for drug approval and other analyses that may shape drug coverage policies, such as budget impact and comparative effectiveness. This study aimed to clarify and explore the zero-price conundrum to provide a resource in the development of practical and methodological solutions. METHODS: We specified equations representing previously identified zero-price scenarios and used them to elucidate factors contributing to the zero-price conundrum and explore relationships between them. We present real-world considerations and discuss solutions from the literature. RESULTS: The analyses demonstrated that a primary cause of the zero-price problem for a new drug that increases quality-adjusted survival pertains to healthcare costs beyond the influence of the new drug, specifically, disease background costs, costs of existing drugs used in a combination regimen, and costs of future health interventions patients may become eligible to receive. Pragmatic solutions have been to exclude such costs from cost-effectiveness analyses. Proposed modifications to cost-effectiveness analysis include assessing each drug in a combination regimen based on its relative contribution to improved health. CONCLUSIONS: The zero-price dilemma may arise more frequently as the number of drugs in high-cost disease areas continues to grow. As cost-effectiveness methods evolve, there is the opportunity to develop robust solutions that can be applied consistently.

A disease progression model estimating the benefit of tolvaptan on time to end-stage renal disease for patients with rapidly progressing autosomal dominant polycystic kidney disease.

BACKGROUND: Tolvaptan was approved in the United States in 2018 for patients with autosomal dominant polycystic kidney disease (ADPKD) at risk of rapid progression as assessed in a 3-year phase 3 clinical trial (TEMPO 3:4). An extension study (TEMPO 4:4) showed continued delay in progression at 2 years, and a trial in patients with later-stage disease (REPRISE) provided confirmatory evidence of efficacy. Given the relatively shorter-term duration of the clinical trials, estimating the longer-term benefit associated with tolvaptan via extrapolation of the treatment effect is an important undertaking. METHODS: A model was developed to simulate a cohort of patients with ADPKD at risk of rapid progression and predict their long-term outcomes using an algorithm organized around the Mayo Risk Classification system, which has five subclasses (1A through 1E) based on estimated kidney growth rates. The model base-case population represents 1280 patients enrolled in TEMPO 3:4 beginning in chronic kidney disease (CKD) stages G1, G2, and G3 across Mayo subclasses 1C, 1D, and 1E. The algorithm was used to predict longer-term natural history health outcomes. The estimated treatment effect of tolvaptan from TEMPO 3:4 was applied to the natural history to predict the longer-term treatment benefit of tolvaptan. For the cohort, analyzed once reflecting natural history and once assuming treatment with tolvaptan, the model estimated lifetime progression through CKD stages, end-stage renal disease (ESRD), and death. RESULTS: When treated with tolvaptan, the model cohort was predicted to experience a 3.1-year delay of ESRD (95% confidence interval: 1.8 to 4.4), approximately a 23% improvement over the estimated 13.7 years for patients not receiving tolvaptan. Patients beginning tolvaptan treatment in CKD stages G1, G2, and G3 were predicted to experience estimated delays of ESRD, compared with patients not receiving tolvaptan, of 3.8 years (21% improvement), 3.0 years (24% improvement), and 2.1 years (28% improvement), respectively. CONCLUSIONS: The model estimated that patients treated with tolvaptan versus no treatment spent more time in earlier CKD stages and had later onset of ESRD. Findings highlight the potential long-term value of early intervention with tolvaptan in patients at risk of rapid ADPKD progression.

The evolution of ICER's review process for new medical interventions and a critical review of economic evaluations (2018-2019): how stakeholders can collaborate with ICER to improve the quality of evidence in ICER's reports.

BACKGROUND: Since its inception in 2006, the Institute for Clinical and Economic Review (ICER) has rapidly gained influence on drug pricing and reimbursement decisions despite historical resistance to the use of cost-effectiveness thresholds in the US health care system. Although patient groups, physicians, and pharmaceutical manufacturers voiced their concerns about the potential negative effects of increased use of ICER's assessments on patient access to innovative medications, there is little guidance and consensus on how the stakeholders should collaborate with ICER to ensure that its reviews reflect the best clinical and economic evidence. OBJECTIVES: To (1) summarize the evolution of ICER's evaluation procedure, scope, and topics; (2) evaluate the effectiveness of stakeholder engagement approaches; and (3) inform stakeholders of their potential role in collaborating with ICER in estimating the cost-effectiveness of new interventions. METHODS: Publicly available ICER evaluations from 2008 to 2019 were systematically reviewed. Changes in evaluation procedures, scope, and topics were summarized. For evaluations that occurred in 2018 (n = 12) and 2019 (n = 8), key characteristics were extracted from 172 letters documenting interactions between ICER and all stakeholders who provided comments to draft reports. Stakeholder suggestions were analyzed in terms of their effectiveness indicated by ICER's reconsideration of its original cost-effectiveness analysis approach. RESULTS: The number of ICER evaluations increased consistently from 2 to 12 per year between 2008 and 2018 but declined to 8 in 2019. Stakeholder opportunity to engage with ICER increased from 1 to 3 per evaluation between 2008 and 2015. ICER initially focused on reviewing general treatment strategies but shifted its focus to specific pharmaceuticals and medical devices in 2014. In 2018 and 2019, 30% of 172 stakeholder letters resulted in a revision in the base-case analysis (49 comments in 2018, 23 in 2019); nearly half of comments in these letters included specific alternative data or a published article to rationalize recommendations. Other common types of suggestions that resulted in ICER's base-case analysis revisions included comments relating to inconsistent methods used to derive model inputs across different treatments (12/49 in 2018, 5/23 in 2019); clinical justifications (12/49 in 2018, 0/23 in 2019); and justifications based on patient perspectives (1/49 in 2018, 5/23 in 2019). These revisions rarely affected ICER's conclusions on the cost-effectiveness of evaluated interventions. Among the 20 assessments that involved 172 stakeholder engagements in 2018 and 2019, only 2% (n = 3) of the engagements (all from 2018) were associated with a change in the cost-effectiveness conclusion. CONCLUSIONS: Between 2018 and 2019, stakeholders leveraged ICER evaluations as opportunities to promote dialogue for better understanding of the value of technologies. Actionable, evidence-based recommendations were accepted more often than other recommendations. DISCLOSURES: No outside funding supported this study. The authors have no conflicts of interest to disclose. Findings from this study were presented as a poster at Virtual ISPOR, May 17-20, 2021.

Cost- Effectiveness of Avatrombopag for the Treatment of Thrombocytopenia in Patients with Chronic Liver Disease.

BACKGROUND AND AIM: Thrombocytopenia is common in people with chronic liver disease, who frequently undergo invasive procedures. To minimize the risk of bleeding, prophylactic platelet transfusions have traditionally been used but carry many risks. The aim of this study was to evaluate the cost-effectiveness of avatrombopag compared with platelet transfusion and lusutrombopag as a treatment for thrombocytopenia in adult patients with chronic liver disease scheduled to undergo a medical procedure. METHODS: A decision-tree model was developed from a US payer perspective to capture acute events observed in phase 3 global randomized controlled clinical trials and, to support exploratory analyses, potential longer-term complications resulting from a major bleed or thromboembolic event. Treatment costs were taken from publicly available data sources. The interventions were evaluated in the overall trial populations and in subpopulations with higher and lower baseline platelet counts. Results were presented as incremental cost per platelet transfusion avoided. One-way and probabilistic sensitivity analyses were conducted. RESULTS: In the overall population, avatrombopag reduced the need for platelet transfusions and produced cost-savings compared with platelet transfusion (80% fewer prophylactic platelet transfusions, $4250 lower costs) and lusutrombopag (42% fewer prophylactic platelet transfusions, $5819 lower costs). Similar results were seen in both the higher and lower platelet count subpopulations. The one-way and probabilistic sensitivity analyses found that the use of avatrombopag is cost-saving with the incremental cost-effectiveness ratio in quadrant IV (decreased costs, prophylactic platelet transfusions avoided). CONCLUSION: The use of avatrombopag is expected to be cost-saving while reducing the need for prophylactic platelet transfusions compared with platelet transfusion and lusutrombopag.

18F-Choline PET/mpMRI for Detection of Clinically Significant Prostate Cancer: Part 1. Improved Risk Stratification for MRI-Guided Transrectal Prostate Biopsies.

A prospective single-arm clinical trial was conducted to determine whether 18F-choline PET/mpMRI can improve the specificity of multiparametric MRI (mpMRI) of the prostate for Gleason ≥ 3+4 prostate cancer. Methods: Before targeted and systematic prostate biopsy, mpMRI and 18F-choline PET/CT were performed on 56 evaluable subjects with 90 Likert score 3-5 mpMRI target lesions, using a 18F-choline target-to-background ratio of greater than 1.58 to indicate a positive 18F-choline result. Prostate biopsies were performed after registration of real-time transrectal ultrasound with T2-weighted MRI. A mixed-effects logistic regression was applied to measure the performance of mpMRI (based on prospective Likert and retrospective Prostate Imaging Reporting and Data System, version 2 [PI-RADS], scores) compared with 18F-choline PET/mpMRI to detect Gleason ≥ 3+4 cancer. Results: The per-lesion accuracy of systematic plus targeted biopsy for mpMRI alone was 67.8% (area under receiver-operating-characteristic curve [AUC], 0.73) for Likert 4-5 and 70.0% (AUC, 0.76) for PI-RADS 3-5. Several PET/MRI models incorporating 18F-choline with mpMRI data were investigated. The most promising model selected all high-risk disease on mpMRI (Likert 5 or PI-RADS 5) plus low- and intermediate-risk disease (Likert 4 or PI-RADS 3-4), with an elevated 18F-choline target-to-background ratio greater than 1.58 as positive for significant cancer. Using this approach, the accuracy on a per-lesion basis significantly improved to 88.9% for Likert (AUC, 0.90; P < 0.001) and 91.1% for PI-RADS (AUC, 0.92; P < 0.001). On a per-patient basis, the accuracy improved to 92.9% for Likert (AUC, 0.93; P < 0.001) and to 91.1% for PI-RADS (AUC, 0.91; P = 0.009). Conclusion:18F-choline PET/mpMRI improved the identification of Gleason ≥ 3+4 prostate cancer compared with mpMRI, with the principal effect being improved risk stratification of intermediate-risk mpMRI lesions.

Value of clinical trial narrative data to estimate the costs of adverse event management: a feasibility study.

Aims: The objective of this feasibility study was to determine the extent to which data from randomized controlled trials (RCTs) may serve as a useful source for collecting health care resource use (HCRU) for the purposes of estimating costs of managing adverse events (AEs), specifically, grade 3-4 nausea and thrombocytopenia, which may be experienced during chemotherapy treatment.Materials and Methods: The feasibility study was conducted in four steps: (1) HCRU data were extracted from patient narratives in four phase 3 RCTs in non-small cell lung cancer; (2) missing HCRU data were imputed; (3) unit costs were applied to the resulting HCRU data set and costs of managing AEs were estimated; and (4) the overall utility of using RCT data as a source for estimating costs of AEs was evaluated.Results: 33 nausea and 68 thrombocytopenia AEs met eligibility criteria and were evaluated in this study. Medication usage was recorded as a treatment in 76% of nausea AEs, although only 14% of the instances of medication usage included the minimum data elements required for costing. Platelet transfusions were provided in 24% of thrombocytopenia AEs; however, in only one instance were the minimum data elements recorded. Of nausea and thrombocytopenia AEs, 18% and 72%, respectively, required no missing data assumptions or imputation.Limitations: Only two AEs were considered, and they may not be representative of all AEs in terms of suitability for use in estimating HCRU and costs of managing AEs. Not all grade 3-4 AEs met the criteria for requiring a patient narrative. HCRU data in the narratives were incomplete.Conclusions: The usefulness of RCTs for estimating the costs of AEs may be improved by using a standardized form to collect HCRU data for key AEs, including an appropriate level of detail required to estimate costs of managing the AEs.

A framework for assessing the lifetime economic burden of congenital cytomegalovirus in the United States.

BACKGROUND: In the United States (US), congenital cytomegalovirus infection (cCMVi) is a major cause of permanent disabilities and the most common etiology of non-genetic sensorineural hearing loss. Evaluations of prevention strategies will require estimates of the economic implications of cCMVi. We aimed to develop a conceptual framework to characterize the lifetime economic burden of cCMVi in the US and to use that framework to identify data gaps. METHODS: Direct health care, direct non-health care, indirect, and intangible costs associated with cCMVi were considered. An initial framework was constructed based on a targeted literature review, then validated and refined after consultation with experts. Published costs were identified and used to populate the framework. Data gaps were identified. RESULTS: The framework was constructed as a chance tree, categorizing clinical event occurrence to form patient profiles associated with distinct economic trajectories. The distribution and magnitude of costs varied by patient life stage, cCMVi diagnosis, severity of impairment, and developmental delays/disabilities. Published studies could not fully populate the framework. The literature best characterized direct health care costs associated with the birth period. Gaps existed for direct non-health care, indirect, and intangible costs, as well as health care costs associated with adult patients and those severely impaired. CONCLUSIONS: Data gaps exist concerning the lifetime economic burden of cCMVi in the US. The conceptual framework provides the basis for a research agenda to address these gaps. Understanding the full lifetime economic burden of cCMVi would inform clinicians, researchers, and policymakers, when assessing the value of cCMVi interventions.

18F-Choline PET/mpMRI for Detection of Clinically Significant Prostate Cancer: Part 2. Cost-Effectiveness Analysis.

The objective of this study was to evaluate the cost-effectiveness of 18F-choline PET/multiparametric MRI (mpMRI) versus mpMRI alone for the detection of primary prostate cancer with a Gleason score of greater than or equal to 3 + 4 in men with elevated prostate-specific antigen levels. Methods: A Markov model of prostate cancer onset and progression was used to estimate the health and economic consequences of 18F-choline PET/mpMRI for the detection of primary prostate cancer with a Gleason score of greater than or equal to 3 + 4 in men with elevated prostate-specific antigen levels. Multiple simultaneous hybrid 18F-choline PET/mpMRI strategies were evaluated using Likert or Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) scoring; the first was biopsy for Likert 5 mpMRI lesions or Likert 3-4 lesions with 18F-choline target-to-background ratios of greater than or equal to 1.58, and the second was biopsy for PI-RADSv2 5 mpMRI lesions or PI-RADSv2 3-4 mpMRI lesions with 18F-choline target-to-background ratios of greater than or equal to 1.58. These strategies were compared with universal standard biopsy, mpMRI alone with biopsy only for PI-RADSv2 3-5 lesions, and mpMRI alone with biopsy only for Likert 4-5 lesions. For each mpMRI strategy, either no biopsy or standard biopsy could be performed after negative mpMRI results were obtained. Deaths averted, quality-adjusted life years (QALYs), cost, and incremental cost-effectiveness ratios were estimated for each strategy. Results: When the results of 18F-choline PET/mpMRI were negative, performing a standard biopsy was more expensive and had lower QALYs than performing no biopsy. The best screening strategy among those considered in this study performed hybrid 18F-choline PET/mpMRI with Likert scoring on men with elevated PSA, performed combined biopsy (targeted biopsy and standard 12-core biopsy) for men with positive imaging results, and no biopsy for men with negative imaging results ($22,706/QALY gained relative to mpMRI alone); this strategy reduced the number of biopsies by 35% in comparison to mpMRI alone. When the same policies were compared using PI-RADSv2 instead of Likert scoring, hybrid 18F-choline PET/mpMRI cost $46,867/QALY gained relative to mpMRI alone. In a threshold analysis, the best strategy among those considered remained cost-effective when the sensitivity and specificity of PET/mpMRI and combined biopsy (targeted biopsy and standard 12-core biopsy) were simultaneously reduced by 20 percentage points. Conclusion:18F-choline PET/mpMRI for the detection of primary prostate cancer with a Gleason score of greater than or equal to 3 + 4 is cost-effective and can reduce the number of unneeded biopsies in comparison to mpMRI alone.

Cost estimate of platelet transfusion in the United States for patients with chronic liver disease and associated thrombocytopenia undergoing elective procedures.

AIMS: This study aimed to estimate the cost of platelet transfusion in patients with chronic liver disease (CLD)-associated thrombocytopenia undergoing an elective procedure in the United States. MATERIALS AND METHODS: The study was conducted in two parts: development of a conceptual framework identifying direct, indirect and intangible costs of platelet transfusion, followed by the estimation of the total cost of platelet transfusion in patients with CLD-associated thrombocytopenia before an elective procedure in the United States using the conceptual framework and cost data obtained from a literature search. The cost of the entire care required to raise a patient's platelet count before the procedure was considered. RESULTS: The final conceptual framework included the costs of generating the supply of platelets, the platelet transfusion itself, adverse events associated with platelet transfusion and refractoriness to platelet transfusion. When costs were accounted for in all the framework cost categories, the total direct cost of a platelet transfusion in a patient with CLD and associated thrombocytopenia was estimated to be in the range of $5258 to $13,117 (2017 US dollars) in the United States. The largest portion of costs was incurred by the transfusion event itself ($3723 to $4436) and the cost of refractoriness ($874 to $7578), which included the opportunity cost of a delayed procedure and subsequent platelet transfusions with human leukocyte antigen-matched platelets. LIMITATIONS AND CONCLUSIONS: Although we were unable to include all cost components identified in the conceptual framework in our total cost estimate, thus likely underestimating the true total cost, and despite the data gaps and challenges limiting our estimate of the full cost of a platelet transfusion in patients with CLD-associated thrombocytopenia undergoing an elective procedure in the United States, this study outlines a comprehensive conceptual framework for estimating the cost elements of a platelet transfusion in these patients.

Cost-effectiveness of magnetic resonance imaging and targeted fusion biopsy for early detection of prostate cancer.

OBJECTIVE: To determine how best to use magnetic resonance imaging (MRI) and targeted MRI/ultrasonography fusion biopsy for early detection of prostate cancer (PCa) in men with elevated prostate-specific antigen (PSA) concentrations and whether it can be cost-effective. METHODS: A Markov model of PCa onset and progression was developed to estimate the health and economic consequences of PCa screening with MRI. Patients underwent PSA screening from ages 55 to 69 years. Patients with elevated PSA concentrations (>4 ng/mL) underwent MRI, followed by targeted fusion or combined (standard + targeted fusion) biopsy on positive MRI, and standard or no biopsy on negative MRI. Prostate Imaging Reporting and Data System (PI-RADS) score on MRI was used to determine biopsy decisions. Deaths averted, quality-adjusted life-years (QALYs), cost and incremental cost-effectiveness ratio (ICER) were estimated for each strategy. RESULTS: With a negative MRI, standard biopsy was more expensive and had lower QALYs than performing no biopsy. The optimum screening strategy (ICER $23 483/QALY) recommended combined biopsy for patients with PI-RADS score ≥3 and no biopsy for patients with PI-RADS score <3, and reduced the number of screening biopsies by 15%. Threshold analysis suggests MRI continues to be cost-effective when the sensitivity and specificity of MRI and combined biopsy are simultaneously reduced by 19 percentage points. CONCLUSIONS: Our analysis suggests MRI followed by targeted MRI/ultrasonography fusion biopsy can be a cost-effective approach to the early detection of PCa.

Optimizing active surveillance strategies to balance the competing goals of early detection of grade progression and minimizing harm from biopsies.

BACKGROUND: Active surveillance (AS) for prostate cancer includes follow-up with serial prostate biopsies. The optimal biopsy frequency during follow-up has not been determined. The goal of this investigation was to use longitudinal AS biopsy data to assess whether the frequency of biopsy could be reduced without substantially prolonging the time to the detection of disease with a Gleason score ≥ 7. METHODS: With data from 1375 men with low-risk prostate cancer enrolled in AS at Johns Hopkins, a hidden Markov model was developed to estimate the probability of undersampling at diagnosis, the annual probability of grade progression, and the 10-year cumulative probability of reclassification or progression to Gleason score ≥ 7. It simulated 1024 potential AS biopsy strategies for the 10 years after diagnosis. For each of these strategies, the model predicted the mean delay in the detection of disease with a Gleason score ≥ 7. RESULTS: The model estimated the 10-year cumulative probability of reclassification from a Gleason score of 6 to a Gleason score ≥ 7 to be 40.0%. The probability of undersampling at diagnosis was 9.8%, and the annual progression probability for men with a Gleason score of 6 was 4.0%. On the basis of these estimates, a simulation of an annual biopsy strategy estimated the mean time to the detection of disease with a Gleason score ≥ 7 to be 14.1 months; however, several strategies eliminated biopsies with only small delays (<12 months) in detecting grade progression. CONCLUSIONS: Although annual biopsy for low-risk men on AS is associated with the shortest time to the detection of disease with a Gleason score ≥ 7, several alternative strategies may allow less frequent biopsying without sizable delays in detecting grade progression. Cancer 2018;124:698-705. © 2017 American Cancer Society.

Two-Stage Biomarker Protocols for Improving the Precision of Early Detection of Prostate Cancer.

BACKGROUND: New cancer biomarkers are being discovered at a rapid pace; however, these tests vary in their predictive performance characteristics, and it is unclear how best to use them. METHODS: We investigated 2-stage biomarker-based screening strategies in the context of prostate cancer using a partially observable Markov model to simulate patients' progression through prostate cancer states to mortality from prostate cancer or other causes. Patients were screened every 2 years from ages 55 to 69. If the patient's serum prostate-specific antigen (PSA) was over a specified threshold in the first stage, a second stage biomarker test was administered. We evaluated design characteristics for these 2-stage strategies using 7 newly discovered biomarkers as examples. Monte Carlo simulation was used to estimate the number of screening biopsies, prostate cancer deaths, and quality-adjusted life-years (QALYs) per 1000 men. RESULTS: The all-cancer biomarkers significantly underperformed the high-grade cancer biomarkers in terms of QALYs. The screening strategy that used a PSA threshold of 2 ng/mL and a second biomarker test with high-grade sensitivity and specificity of 0.86 and 0.62, respectively, maximized QALYs. This strategy resulted in a prostate cancer death rate within 1% of using PSA alone with a threshold of 2 ng/mL, while reducing the number of biopsies by 20%. Sensitivity analysis suggests that the results are robust with respect to variation in model parameters. CONCLUSIONS: Two-stage biomarker screening strategies using new biomarkers with risk thresholds optimized for high-grade cancer detection may increase quality-adjusted survival and reduce unnecessary biopsies.

Assessment of long-term outcomes associated with urinary prostate cancer antigen 3 and TMPRSS2:ERG gene fusion at repeat biopsy.

BACKGROUND: In men with clinically localized prostate cancer who have undergone at least 1 previous negative biopsy and have elevated serum prostate-specific antigen (PSA) levels, long-term health outcomes associated with the assessment of urinary prostate cancer antigen 3 (PCA3) and the transmembrane protease, serine 2 (TMPRSS2):v-ets erythroblastosis virus E26 oncogene homolog (avian) (ERG) gene fusion (T2:ERG) have not been investigated previously in relation to the decision to recommend a repeat biopsy. METHODS: The authors performed a decision analysis using a decision tree for men with elevated PSA levels. The probability of cancer was estimated using the Prostate Cancer Prevention Trial Risk Calculator (version 2.0). The use of PSA alone was compared with the use of PCA3 and T2:ERG scores, with each evaluated independently, in combination with PSA to trigger a repeat biopsy. When PCA3 and T2:ERG score evaluations were used, predefined thresholds were established to determine whether the patient should undergo a repeat biopsy. Biopsy outcomes were defined as either positive (with a Gleason score of <7, 7, or >7) or negative. Probabilities and estimates of 10-year overall survival and 15-year cancer-specific survival were derived from previous studies and a literature review. Outcomes were defined as age-dependent and Gleason score-dependent 10-year overall and 15-year cancer-specific survival rates and the percentage of biopsies avoided. RESULTS: Incorporating the PCA3 score (biopsy threshold, 25; generated based on the urine PCA3 level normalized to the amount of PSA messenger RNA) or the T2:ERG score (biopsy threshold, 10; based on the urine T2:ERG level normalized to the amount of PSA messenger RNA) into the decision to recommend repeat biopsy would have avoided 55.4% or 64.7% of repeat biopsies for the base-case patient, respectively, and changes in the 10-year survival rate were only 0.93% or 1.41%, respectively. Multi-way sensitivity analyses suggested that these results were robust with respect to the model parameters. CONCLUSIONS: The use of PCA3 or T2:ERG testing for repeat biopsy decisions can substantially reduce the number of biopsies without significantly affecting 10-year survival.

Clinical predictors and recommendations for staging computed tomography scan among men with prostate cancer.

OBJECTIVE: To identify clinical variables associated with a positive computed tomography (CT) scan and estimate the performance of imaging recommendations in patients from a diverse sample of urology practices. MATERIALS AND METHODS: This study comprised 2380 men with newly diagnosed prostate cancer seen at 28 practices in the Michigan Urological Surgery Improvement Collaborative from March 2012 through September 2013. Data included age, prostate-specific antigen (PSA) level, Gleason score (GS), clinical T stage, total number of positive biopsy cores, whether or not the patient received a staging abdominal and/or pelvic CT scan, and CT scan result. We fit a multivariate logistic regression model to identify clinical variables associated with metastases detected by CT scan. We estimated the sensitivity and specificity of existing imaging recommendations. RESULTS: Among 643 men (27.4%) who underwent a staging CT scan, 62 men (9.6%) had a positive study. In the multivariate analysis, PSA, GS, and clinical T stage were independently associated with the occurrence of a positive CT scan (all P values <.05). The American Urological Association's Best Practice Statements' recommendations for imaging when PSA level >20 ng/mL or GS ≥ 8 or locally advanced cancer had a sensitivity of 87.3% and specificity of 82.6%. Compared with current practice, implementing this recommendation in the Michigan Urological Surgery Improvement Collaborative population was estimated to result in approximately 0.5% of positive study results being missed, and 26.1% of fewer study results overall. CONCLUSION: Successful implementation of CT imaging criterion of PSA level >20, GS ≥ 8, or clinical stage ≥ T3 would ensure that CT scans are performed for almost all men who would have positive study results while reducing the number of negative study results.

Toward better use of bone scans among men with early-stage prostate cancer.

OBJECTIVE: To evaluate the performance of published guidelines compared with that of current practice for radiographic staging of men with newly diagnosed prostate cancer. MATERIALS AND METHODS: Using data from the Michigan Urological Surgery Improvement Collaborative clinical registry, we identified 1509 men diagnosed with prostate cancer from March 2012 through June 2013. Clinical data included age, prostate-specific antigen (PSA) level, Gleason score (GS), clinical trial stage, number of biopsy cores, and bone scan (BS) results. We then fit a multivariate logistic regression model to examine the association between clinical variables and the occurrence of bone metastases. Because some patients did not undergo BS, we used established methods to correct for verification bias and estimate the diagnostic accuracy of published guidelines. RESULTS: Among 416 men who received a BS, 48 (11.5%) had evidence of bone metastases. Patients with bone metastases were older, with higher PSA levels and GS (all P <.05). In multivariate analyses, PSA (P <.001) and GS (P = .004) were the only independent predictors of positive BS. Guidelines from the American Urological Association and the National Comprehensive Cancer Network demonstrated similar performance in detecting bone metastases in our population, with fewer negative study results than those of the European Association of Urology guideline. Applying the American Urological Association recommendations (ie, image when PSA level >20 ng/mL or GS ≥ 8) to current clinical practice, we estimate that <1% of positive study results would be missed, whereas the number of negative study results would be reduced by 38%. CONCLUSION: Based on current practice patterns, more uniform application of existing guidelines would ensure that BS is performed for almost all men with bone metastases, while avoiding many negative imaging studies.

Genetic profiling to determine risk of relapse-free survival in high-risk localized prostate cancer.

PURPOSE: The characterization of actionable mutations in human tumors is a prerequisite for the development of individualized, targeted therapy. We examined the prevalence of potentially therapeutically actionable mutations in patients with high-risk clinically localized prostate cancer. EXPERIMENTAL DESIGN: Forty-eight samples of formalin-fixed paraffin-embedded prostatectomy tissue from a neoadjuvant chemotherapy trial were analyzed. DNA extracted from microdissected tumor was analyzed for 643 common solid tumor mutations in 53 genes using mass spectroscopy-based sequencing. In addition, PTEN loss and erythroblast transformation-specific-related gene (ERC) translocations were examined using immunohistochemistry (IHC) in associated tissue microarrays. Association with relapse during 5 years of follow-up was examined in exploratory analyses of the potential clinical relevance of the genetic alterations. RESULTS: Of the 40 tumors evaluable for mutations, 10% had point mutations in potentially actionable cancer genes. Of the 47 tumors evaluable for IHC, 36% had PTEN loss and 40% had ERG rearrangement. Individual mutations were not frequent enough to determine associations with relapse. Using Kaplan-Meier analysis with a log-rank test, the 16 patients who had PTEN loss had a significantly shorter median relapse-free survival, 19 versus 106 months (P = 0.01). CONCLUSIONS: This study confirms that point mutations in the most common cancer regulatory genes in prostate cancer are rare. However, the PIK3CA/AKT pathway was mutated in 10% of our samples. Although point mutations alone did not have a statistically significant association with relapse, PTEN loss was associated with an increased relapse in high-risk prostate cancer treated with chemotherapy followed by surgery.

Gastrointestinal stromal tumors: molecular markers and genetic subtypes.

Mutation-activated signaling from the KIT and PDGFRA kinases has been successfully targeted in gastrointestinal stromal tumors (GISTs), with subtle differences between the mutations serving to refine prognosis and more precisely tailor therapy. There is a growing understanding of the molecular drivers of GISTs lacking mutations in KIT or PDGFRA, so called wild-type GISTs, further aiding in management decisions. This article provides an overview of all the known molecular subtypes of GIST and provides information about clinical correlates, treatment, and prognosis depending on the subtype.

Management of tyrosine kinase inhibitor-resistant gastrointestinal stromal tumors.

The treatment of gastrointestinal stromal tumors (GISTs) has been a model for targeted cancer therapy. The discovery of driver somatic mutations in the KIT and PDGFRA receptor tyrosine kinases led to a shift of therapy from conventional cytotoxic chemotherapy to inhibitors of these receptors. Targeted molecular therapy of GIST has markedly increased the overall survival of patients with advanced disease. However, the ability of kinase therapy to control metastatic disease is ultimately limited by the ability of these agents to overcome intrinsic or acquired resistance mechanisms. Ongoing basic and clinical research is focusing on identifying new agents to inhibit KIT/PDGFRA kinase activity and/or other novel molecular targets in GIST.