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1.
Eur Radiol ; 34(7): 4504-4515, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38099965

RESUMEN

OBJECTIVES: The aim of this proof-of-principle study combining data analysis and computer simulation was to evaluate the robustness of apparent diffusion coefficient (ADC) values for lymph node classification in prostate cancer under conditions comparable to clinical practice. MATERIALS AND METHODS: To assess differences in ADC and inter-rater variability, ADC values of 359 lymph nodes in 101 patients undergoing simultaneous prostate-specific membrane antigen (PSMA)-PET/MRI were retrospectively measured by two blinded readers and compared in a node-by-node analysis with respect to lymph node status. In addition, a phantom and 13 patients with 86 lymph nodes were prospectively measured on two different MRI scanners to analyze inter-scanner agreement. To estimate the diagnostic quality of the ADC in real-world application, a computer simulation was used to emulate the blurring caused by scanner and reader variability. To account for intra-individual correlation, the statistical analyses and simulations were based on linear mixed models. RESULTS: The mean ADC of lymph nodes showing PSMA signals in PET was markedly lower (0.77 × 10-3 mm2/s) compared to inconspicuous nodes (1.46 × 10-3 mm2/s, p < 0.001). High inter-reader agreement was observed for ADC measurements (ICC 0.93, 95%CI [0.92, 0.95]). Good inter-scanner agreement was observed in the phantom study and confirmed in vivo (ICC 0.89, 95%CI [0.84, 0.93]). With a median AUC of 0.95 (95%CI [0.92, 0.97]), the simulation study confirmed the diagnostic potential of ADC for lymph node classification in prostate cancer. CONCLUSION: Our model-based simulation approach implicates a high potential of ADC for lymph node classification in prostate cancer, even when inter-rater and inter-scanner variability are considered. CLINICAL RELEVANCE STATEMENT: The ADC value shows a high diagnostic potential for lymph node classification in prostate cancer. The robustness to scanner and reader variability implicates that this easy to measure and widely available method could be readily integrated into clinical routine. KEY POINTS: • The diagnostic value of the apparent diffusion coefficient (ADC) for lymph node classification in prostate cancer is unclear in the light of inter-rater and inter-scanner variability. • Metastatic and inconspicuous lymph nodes differ significantly in ADC, resulting in a high diagnostic potential that is robust to inter-scanner and inter-rater variability. • ADC has a high potential for lymph node classification in prostate cancer that is maintained under conditions comparable to clinical practice.


Asunto(s)
Ganglios Linfáticos , Metástasis Linfática , Neoplasias de la Próstata , Humanos , Masculino , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Metástasis Linfática/diagnóstico por imagen , Anciano , Persona de Mediana Edad , Ganglios Linfáticos/diagnóstico por imagen , Ganglios Linfáticos/patología , Estudios Retrospectivos , Fantasmas de Imagen , Imagen de Difusión por Resonancia Magnética/métodos , Tomografía de Emisión de Positrones/métodos , Simulación por Computador , Estudios Prospectivos , Imagen Multimodal/métodos , Variaciones Dependientes del Observador
2.
Age Ageing ; 52(6)2023 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-37368870

RESUMEN

BACKGROUND: age-related fragility fractures cause significant burden of disease. Within an ageing society, fracture and complication prevention will be essential to balance health expenditure growth. OBJECTIVE: to assess the effect of anti-osteoporotic therapy on surgical complications and secondary fractures after treatment of fragility fractures. PATIENTS AND METHODS: retrospective health insurance data from January 2008 to December 2019 of patients ≥65 years with proximal humeral fracture (PHF) treated using locked plate fixation (LPF) or reverse total shoulder arthroplasty were analysed. Cumulative incidences were calculated by Aalen-Johansen estimates. The influence of osteoporosis and pharmaceutical therapy on secondary fractures and surgical complications were analysed using multivariable Fine and Gray Cox regression models. RESULTS: a total of 43,310 patients (median age 79 years, 84.4% female) with a median follow-up of 40.9 months were included. Five years after PHF, 33.4% of the patients were newly diagnosed with osteoporosis and only 19.8% received anti-osteoporotic therapy. A total of 20.6% (20.1-21.1%) of the patients had at least one secondary fracture with a significant reduction of secondary fracture risk by anti-osteoporotic therapy (P < 0.001). An increased risk for surgical complications (hazard ratio: 1.35, 95% confidence interval: 1.25-1.47, P < 0.001) after LPF could be reversed by anti-osteoporotic therapy. While anti-osteoporotic therapy was more often used in female patients (35.3 vs 19.1%), male patients showed significantly stronger effects reducing the secondary fracture and surgical complication risk. CONCLUSIONS: a significant number of secondary fractures and surgical complications could be prevented by consequent osteoporosis diagnosis and treatment particularly in male patients. Health-politics and legislation must enforce guideline-based anti-osteoporotic therapy to mitigate burden of disease.


Asunto(s)
Fracturas del Húmero , Osteoporosis , Fracturas del Hombro , Humanos , Masculino , Femenino , Anciano , Fijación Interna de Fracturas/efectos adversos , Estudios Retrospectivos , Osteoporosis/complicaciones , Osteoporosis/tratamiento farmacológico , Fracturas del Hombro/cirugía , Fracturas del Hombro/complicaciones , Fracturas del Húmero/complicaciones , Resultado del Tratamiento
3.
J Shoulder Elbow Surg ; 32(8): 1574-1583, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36682708

RESUMEN

HYPOTHESIS: Common surgical treatment options for proximal humeral fractures in elderly patients include locked plate fixation (LPF) and reverse total shoulder arthroplasty (RTSA). It was hypothesized that secondary RTSA after LPF would be associated with higher complication rates and costs compared with primary RTSA. METHODS: We analyzed the health insurance data of patients aged ≥65 years who received RTSA for the treatment of a proximal humeral fracture between January 2013 and September 2019 with a pre-study phase of 5 years. Multivariable Cox, logistic, and linear regression models were used to evaluate the association between treatment group and complications, hospital length of stay, charges, and mortality rate during a 34-month follow-up period. RESULTS: A total of 14,220 patients underwent primary RTSA and 1282 patients underwent secondary RTSA after prior surgery using LPF for the treatment of proximal humeral fractures. After adjustment for patient characteristics, more surgical complications were observed after secondary RTSA during index hospitalization (odds ratio, 4.62; 95% confidence interval [CI], 4.00-5.34; P < .001) and long-term follow-up (hazard ratio, 1.52; 95% CI, 1.27-1.81; P < .001). Moreover, secondary RTSA was associated with an increased cumulative total cost of €6638.1 (95% CI, €6229.9-€7046.5; P < .001). If conversion from LPF to secondary RTSA occurred during index hospitalization, more major adverse events, more thromboembolic events, and a higher mortality rate were found in the short and long term (all P < .05). CONCLUSION: Secondary RTSA is associated with higher total costs and more complications. Hence, if surgical treatment of a proximal humeral fracture in an elderly patient is needed, prognostic factors for LPF need to be evaluated carefully. If in doubt, the surgeon should opt to perform primary RTSA as patients will benefit in the long term.


Asunto(s)
Artroplastía de Reemplazo de Hombro , Hemiartroplastia , Fracturas del Hombro , Articulación del Hombro , Anciano , Humanos , Artroplastía de Reemplazo de Hombro/efectos adversos , Hemiartroplastia/efectos adversos , Reoperación , Fracturas del Hombro/etiología , Rango del Movimiento Articular , Resultado del Tratamiento , Estudios Retrospectivos , Articulación del Hombro/cirugía
4.
Biom J ; 64(2): 312-342, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35152459

RESUMEN

Existing methods concerning the assessment of long-term survival outcomes in one-armed trials are commonly restricted to one primary endpoint. Corresponding adaptive designs suffer from limitations regarding the use of information from other endpoints in interim design changes. Here we provide adaptive group sequential one-sample tests for testing hypotheses on the multivariate survival distribution derived from multi-state models, while making provision for data-dependent design modifications based on all involved time-to-event endpoints. We explicitly elaborate application of the methodology to one-sample tests for the joint distribution of (i) progression-free survival (PFS) and overall survival (OS) in the context of an illness-death model, and (ii) time to toxicity and time to progression while accounting for death as a competing event. Large sample distributions are derived using a counting process approach. Small sample properties are studied by simulation. An already established multi-state model for non-small cell lung cancer is used to illustrate the adaptive procedure.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Ensayos Clínicos Fase II como Asunto , Simulación por Computador , Determinación de Punto Final/métodos , Humanos , Proyectos de Investigación , Tamaño de la Muestra
5.
Clin Orthop Relat Res ; 479(10): 2284-2292, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-33938479

RESUMEN

BACKGROUND: Currently, there seems to be a paradigm change in the surgical treatment of proximal humeral fractures in patients aged 65 years and older, with a considerable increase in the use of reverse total shoulder arthroplasty (RTSA) compared with angular stable internal fixation (locking plate fixation). However, even among shoulder specialists there is controversy regarding the best treatment strategy. QUESTIONS/PURPOSES: To evaluate for (1) a greater risk of in-hospital major adverse events, (2) a greater risk for in-hospital surgical complications, and (3) a greater risk of 30-day mortality, locking plate fixation and RTSA were compared for the treatment of proximal humerus fractures of patients aged 65 years and older after controlling for potentially confounding variables in a large-database analysis. METHODS: Health claims data of the largest German insurance company including approximately one-third of the population (26.5 million policyholders) between 2010 and 2018 were analyzed. This database was chosen because of its size, nationwide distribution, and high quality/completeness. In total, 55,070 patients (≥ 65 years of age) treated with locking plate fixation (75% [41,216]) or RTSA (25% [13,854]) for proximal humeral fracture were compared. As primary endpoints, major adverse events (including acute myocardial infarction, stroke, organ failure, resuscitation, and death) and surgical complications (infection, hematoma, loss of reduction, dislocation, and revision surgery) were analyzed. The risk of all endpoints was analyzed with multivariable logistic regression models in the context of comorbidities to address existing group differences. RESULTS: After controlling for potentially confounding variables such as age, sex, and risk profile, RTSA was associated with a higher risk for major adverse events (OR 1.40 [95% CI 1.29 to 1.53]; p < 0.001) and surgical complications (OR 1.13 [95% CI 1.05 to 1.21]; p < 0.01) compared with locking plate fixation. There was no evidence for an increase in mortality (OR 0.98 [95% CI 0.86 to 1.12]; p = 0.81). CONCLUSION: The increased in-hospital risk for major adverse events and surgical complications may moderate the enthusiasm associated with RTSA for proximal humeral fractures in patients 65 years and older. Treatment decisions should be based on individual risk estimation to avoid potential harmful events. Future studies must include long-term outcomes and quality of life to enlighten these findings in a broader context. LEVEL OF EVIDENCE: Level III, therapeutic study.


Asunto(s)
Artroplastía de Reemplazo de Hombro/métodos , Placas Óseas , Fijación Interna de Fracturas/métodos , Complicaciones Posoperatorias/etiología , Fracturas del Hombro/cirugía , Factores de Edad , Anciano , Femenino , Alemania , Humanos , Masculino
6.
Eur Heart J ; 41(38): 3732-3739, 2020 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-31593987

RESUMEN

AIMS: Drug-eluting devices (DED) represent a well-established therapy being widely used for endovascular revascularization (EVR) of peripheral vessels. Recent data indicate a two-fold increased long-term mortality in patients treated with paclitaxel-based DED. The subsequent safety concerns affected international regulatory authorities to enunciate several alerts for further application of DED. METHODS AND RESULTS: In 9.2 million insurants of the German BARMER Health Insurance, data on the application of paclitaxel-based drug-eluting stents (DES) and drug-coated balloons (DCB) were retrieved from their introduction on the market in 2007 until present. All patients with first EVR between 2007 and 2015 were indexed and followed until 31 December 2017. Each subsequently applied DES, DCB, bare-metal stent, and uncoated balloon was included in further analyses. Multivariable Cox regression analysis considered potential non-linear time-dependent hazard ratios (HRs) of DES and DCB over 11 years. We identified 64 771 patients who underwent 107 112 EVR procedures using 23 137 DED. Multivariable Cox regression analysis showed paclitaxel-based DES not to be associated with increased long-term mortality for over 11 years past application (all P > 0.057). DCB was associated with decreased long-term mortality for the first year past application (HR 0.92; P < 0.001), and indifferent correlation in the years thereafter (all P > 0.202). CONCLUSION: Our real-world analysis showed no evidence for increased mortality associated with paclitaxel-based DED for over 11 years.


Asunto(s)
Fármacos Cardiovasculares , Stents Liberadores de Fármacos , Enfermedad Arterial Periférica , Arteria Femoral , Humanos , Paclitaxel , Enfermedad Arterial Periférica/terapia , Stents , Resultado del Tratamiento
7.
Blood ; 128(5): 686-98, 2016 08 04.
Artículo en Inglés | MEDLINE | ID: mdl-27288520

RESUMEN

The clinical and prognostic relevance of many recently identified driver gene mutations in adult acute myeloid leukemia (AML) is poorly defined. We sequenced the coding regions or hotspot areas of 68 recurrently mutated genes in a cohort of 664 patients aged 18 to 86 years treated on 2 phase 3 trials of the German AML Cooperative Group (AMLCG). The median number of 4 mutations per patient varied according to cytogenetic subgroup, age, and history of previous hematologic disorder or antineoplastic therapy. We found patterns of significantly comutated driver genes suggesting functional synergism. Conversely, we identified 8 virtually nonoverlapping patient subgroups, jointly comprising 78% of AML patients, that are defined by mutually exclusive genetic alterations. These subgroups, likely representing distinct underlying pathways of leukemogenesis, show widely divergent outcomes. Furthermore, we provide detailed information on associations between gene mutations, clinical patient characteristics, and therapeutic outcomes in this large cohort of uniformly treated AML patients. In multivariate analyses including a comprehensive set of molecular and clinical variables, we identified DNMT3A and RUNX1 mutations as important predictors of shorter overall survival (OS) in AML patients <60 years, and particularly in those with intermediate-risk cytogenetics. NPM1 mutations in the absence of FLT3-ITD, mutated TP53, and biallelic CEBPA mutations were identified as important molecular prognosticators of OS irrespective of patient age. In summary, our study provides a comprehensive overview of the spectrum, clinical associations, and prognostic relevance of recurrent driver gene mutations in a large cohort representing a broad spectrum and age range of intensively treated AML patients.


Asunto(s)
Leucemia Mieloide Aguda/genética , Mutación/genética , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Análisis Citogenético , Análisis Mutacional de ADN , Femenino , Frecuencia de los Genes/genética , Predisposición Genética a la Enfermedad , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Nucleofosmina , Pronóstico , Factores de Riesgo , Análisis de Supervivencia , Adulto Joven
8.
Haematologica ; 103(11): 1853-1861, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-29903761

RESUMEN

A cute myeloid leukemia is a disease of the elderly (median age at diagnosis, 65-70 years). The prognosis of older acute myeloid leukemia patients is generally poor. While genetic markers have become important tools for risk stratification and treatment selection in young and middle-aged patients, their applicability in very old patients is less clear. We sought to validate existing genetic risk classification systems and identify additional factors associated with outcomes in intensively treated patients aged ≥75 years. In 151 patients who received induction chemotherapy in the AMLCG-1999 trial, we investigated recurrently mutated genes using a targeted sequencing assay covering 64 genes. The median number of mutated genes per patient was four. The most commonly mutated genes were TET2 (42%), DNMT3A (35%), NPM1 (32%), SRSF2 (25%) and ASXL1 (21%). The complete remission rate was 44% and the 3-year survival was 21% for the entire cohort. While adverse-risk cytogenetics (MRC classification) were associated with shorter overall survival (P=0.001), NPM1 and FLT3-ITD mutations (present in 18%) did not have a significant impact on overall survival. Notably, none of the 13 IDH1-mutated patients (9%) reached complete remission. Consequently, the overall survival of this subgroup was significantly shorter than that of IDH1-wildtype patients (P<0.001). In summary, even among very old, intensively treated, acute myeloid leukemia patients, adverse-risk cytogenetics predict inferior survival. The spectrum and relevance of driver gene mutations in elderly patients differs from that in younger patients. Our data implicate IDH1 mutations as a novel marker for chemorefractory disease and inferior prognosis. (AMLCG-1999 trial: clinicaltrials.gov identifier, NCT00266136).


Asunto(s)
Biomarcadores de Tumor/genética , Isocitrato Deshidrogenasa/genética , Leucemia Mieloide Aguda , Proteínas Nucleares/genética , Tirosina Quinasa 3 Similar a fms/genética , Anciano , Anciano de 80 o más Años , Supervivencia sin Enfermedad , Femenino , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidad , Leucemia Mieloide Aguda/terapia , Masculino , Mutación , Nucleofosmina , Medición de Riesgo , Tasa de Supervivencia
9.
Biometrics ; 74(2): 529-537, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-28940387

RESUMEN

Traditional designs in phase IIa cancer trials are single-arm designs with a binary outcome, for example, tumor response. In some settings, however, a time-to-event endpoint might appear more appropriate, particularly in the presence of loss to follow-up. Then the one-sample log-rank test might be the method of choice. It allows to compare the survival curve of the patients under treatment to a prespecified reference survival curve. The reference curve usually represents the expected survival under standard of the care. In this work, convergence of the one-sample log-rank statistic to Brownian motion is proven using Rebolledo's martingale central limit theorem while accounting for staggered entry times of the patients. On this basis, a confirmatory adaptive one-sample log-rank test is proposed where provision is made for data dependent sample size reassessment. The focus is to apply the inverse normal method. This is done in two different directions. The first strategy exploits the independent increments property of the one-sample log-rank statistic. The second strategy is based on the patient-wise separation principle. It is shown by simulation that the proposed adaptive test might help to rescue an underpowered trial and at the same time lowers the average sample number (ASN) under the null hypothesis as compared to a single-stage fixed sample design.


Asunto(s)
Ensayos Clínicos Adaptativos como Asunto/métodos , Ensayos Clínicos como Asunto/métodos , Análisis de Supervivencia , Simulación por Computador , Determinación de Punto Final , Tamaño de la Muestra , Factores de Tiempo
10.
Stat Med ; 34(6): 1031-40, 2015 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-25500942

RESUMEN

An improved method of sample size calculation for the one-sample log-rank test is provided. The one-sample log-rank test may be the method of choice if the survival curve of a single treatment group is to be compared with that of a historic control. Such settings arise, for example, in clinical phase-II trials if the response to a new treatment is measured by a survival endpoint. Present sample size formulas for the one-sample log-rank test are based on the number of events to be observed, that is, in order to achieve approximately a desired power for allocated significance level and effect the trial is stopped as soon as a certain critical number of events are reached. We propose a new stopping criterion to be followed. Both approaches are shown to be asymptotically equivalent. For small sample size, though, a simulation study indicates that the new criterion might be preferred when planning a corresponding trial. In our simulations, the trial is usually underpowered, and the aspired significance level is not exploited if the traditional stopping criterion based on the number of events is used, whereas a trial based on the new stopping criterion maintains power with the type-I error rate still controlled.


Asunto(s)
Ensayos Clínicos Fase II como Asunto/métodos , Tamaño de la Muestra , Análisis de Supervivencia , Antineoplásicos Fitogénicos/uso terapéutico , Simulación por Computador , Quimioterapia Combinada , Humanos , Neuroblastoma/tratamiento farmacológico , Proyectos de Investigación , Resultado del Tratamiento
11.
Acta Neuropathol ; 128(1): 137-49, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24791927

RESUMEN

This study aimed to prospectively evaluate clinical, histopathological and molecular variables for outcome prediction in medulloblastoma patients. Patients from the HIT2000 cooperative clinical trial were prospectively enrolled based on the availability of sufficient tumor material and complete clinical information. This revealed a cohort of 184 patients (median age 7.6 years), which was randomly split at a 2:1 ratio into a training (n = 127), and a test (n = 57) dataset in order to build and test a risk score for this population. Independent validation was performed in a non-overlapping cohort (n = 83). All samples were subjected to thorough histopathological investigation, CTNNB1 mutation analysis, quantitative PCR, MLPA and FISH analyses for cytogenetic variables, and methylome analysis. By univariable analysis, clinical factors (M-stage), histopathological variables (large cell component, endothelial proliferation, synaptophysin pattern), and molecular features (chromosome 6q status, MYC amplification, subgrouping) were found to be prognostic. Molecular consensus subgrouping (WNT, SHH, Group 3, Group 4) was validated as an independent feature to stratify patients into different risk groups. When comparing methods for the identification of WNT-driven medulloblastoma, this study identified CTNNB1 sequencing and methylation profiling to most reliably identify these patients. After removing patients with particularly favorable (CTNNB1 mutation, extensive nodularity) or unfavorable (MYC amplification) markers, a risk score for the remaining "intermediate molecular risk" population dependent on age, M-stage, pattern of synaptophysin expression, and MYCN copy-number status was identified, with speckled synaptophysin expression indicating worse outcome. Test and independent validation of the score confirmed significant discrimination of patients by risk profile. Methylation subgrouping and CTNNB1 mutation status represent robust tools for the risk stratification of medulloblastoma. A simple clinico-pathological risk score was identified, which was confirmed in a test set and by independent clinical validation.


Asunto(s)
Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/patología , Meduloblastoma/diagnóstico , Meduloblastoma/patología , Adolescente , Adulto , Biomarcadores/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Niño , Preescolar , Metilación de ADN , Femenino , Estudios de Seguimiento , Humanos , Lactante , Masculino , Meduloblastoma/genética , Meduloblastoma/metabolismo , Proteína Proto-Oncogénica N-Myc , Estadificación de Neoplasias , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Oncogénicas/genética , Proteínas Oncogénicas/metabolismo , Pronóstico , Estudios Prospectivos , Riesgo , Sinaptofisina/metabolismo , Adulto Joven , beta Catenina/genética , beta Catenina/metabolismo
12.
Biom J ; 56(1): 86-106, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24395207

RESUMEN

Adaptive designs were originally developed for independent and uniformly distributed p-values. There are trial settings where independence is not satisfied or where it may not be possible to check whether it is satisfied. In these cases, the test statistics and p-values of each stage may be dependent. Since the probability of a type I error for a fixed adaptive design depends on the true dependence structure between the p-values of the stages, control of the type I error rate might be endangered if the dependence structure is not taken into account adequately. In this paper, we address the problem of controlling the type I error rate in two-stage adaptive designs if any dependence structure between the test statistics of the stages is admitted (worst case scenario). For this purpose, we pursue a copula approach to adaptive designs. For two-stage adaptive designs without futility stop, we derive the probability of a type I error in the worst case, that is for the most adverse dependence structure between the p-values of the stages. Explicit analytical considerations are performed for the class of inverse normal designs. A comparison with the significance level for independent and uniformly distributed p-values is performed. For inverse normal designs without futility stop and equally weighted stages, it turns out that correcting for the worst case is too conservative as compared to a simple Bonferroni design.


Asunto(s)
Biometría/métodos , Ensayos Clínicos como Asunto/métodos , Humanos
13.
PLoS One ; 19(6): e0305434, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38875270

RESUMEN

The one-sample log-rank test is the preferred method for analysing the outcome of single-arm survival trials. It compares the survival distribution of patients with a prefixed reference survival curve that usually represents the expected outcome under standard of care. However, classical one-sample log-rank tests assume that the reference curve is known, ignoring that it is frequently estimated from historical data and therefore susceptible to sampling error. Neglecting the variability of the reference curve can lead to an inflated type I error rate, as shown in a previous paper. Here, we propose a new survival test that allows to account for the sampling error of the reference curve without knowledge of the full underlying historical survival time data. Our new test allows to perform a valid historical comparison of patient survival times when only a historical survival curve rather than the full historic data is available. It thus applies in settings where the two-sample log-rank test is not applicable as method of choice due to non-availability of historic individual patient survival time data. We develop sample size calculation formulas, give an example application and study the performance of the new test in a simulation study.


Asunto(s)
Simulación por Computador , Humanos , Análisis de Supervivencia , Tamaño de la Muestra , Modelos Estadísticos
14.
Dtsch Arztebl Int ; (Forthcoming)2024 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-38652842

RESUMEN

BACKGROUND: Little is known about the frequency and results of conservative treatment of proximal humerus fractures in older individuals. METHODS: Billing data of the BARMER health insurance carrier for all patients of age 65 and above with proximal humerus fractures in the years 2005-2021 were retrospectively analyzed with multivariable Cox regression models, taking account of the patients' age, sex, and comorbidity profiles. The defined primary endpoints were overall survival (OS), major adverse events (MAE), thromboembolic events (TE), and complications of surgery or of trauma. Multivariable p values for the effect of treatment on all primary endpoints were jointly adjusted with the Bonferroni-Holm method. RESULTS: 54% of 81 909 patients were treated conservatively. Conservative treatment was more common in those who received their diagnosis as outpatients (79.5%, vs. 37.2% for inpatients). Operative treatment was associated with significantly longer overall survival (long-term HR 0.89, 95% confidence interval [0,86; 0,91]) and fewer MAE (0.90; [0.88; 0.92]) and TE (0.89; [0.87; 0.92]), but more complications due to surgery or trauma (1.66; [1,.4; 1.78]; all p < 0.001). 3.1% of the patients who had been initially treated conservatively underwent surgery within 6 months of their diagnosis. Risk factors for the failure of conservative treatment included alcohol abuse, obesity, cancer, diabetes mellitus, Parkinson disease, and osteoporosis. CONCLUSION: The conservative treatment of proximal humerus fracture is associated with a lower overall rate of complications due to surgery or trauma, but also with more MAE and TE and higher overall mortality. These findings underline the need for individualized and risk-adjusted treatment recommendations.

15.
Stroke Vasc Neurol ; 2024 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-38782495

RESUMEN

BACKGROUND: We investigated differences in intracranial embolus distribution through communicating arteries in relation to supra-aortic vessel (SAV) patency. METHODS: For this experimental analysis, we created a silicone model of the extracranial and intracranial circulations using a blood-mimicking fluid under physiological pulsatile flow. We examined the sequence of embolus lodgment on injecting 104 frangible clot analogues (406 emboli) through the right internal carotid artery (CA) as SAV patency changed: (a) all SAV patent (baseline), (b) emboli from a CA occlusion, (c) emboli contralateral to a CA occlusion and (d) occlusion of the posterior circulation. The statistical analysis included a descriptive analysis of thrombi location after occlusion (absolute and relative frequencies). Sequences of occlusions were displayed in Sankey flow charts for the four SAV conditions. Associations between SAV conditions and occlusion location were tested by Fisher's exact test. Two-sided p values were compared with a significance level of 0.05. RESULTS: The total number of emboli was 406 (median fragments/clot: 4 (IQR: 3-5)). Embolus lodgment was dependent on SAV patency (p<0.0001). In all scenarios, embolism lodging in the anterior cerebral artery (ACA) occurred after a previous middle cerebral artery (MCA) embolism (MCA first lodge: 96%, 100/104). The rate of ipsilateral ACA embolism was 28.9% (28/97) at baseline, decreasing significantly when emboli originated from an occluded CA (16%, 14/88). There were more bihemispheric embolisations in cases of contralateral CA occlusion (37%, 45/122), with bilateral ACA embolisms preceding contralateral MCA embolism in 56% of cases (14/25 opposite MCA and ACA embolism). CONCLUSIONS: All emboli in the ACA occurred after a previous ipsilateral MCA embolism. Bihemispheric embolisms were rare, except when there was a coexisting occlusion in either CA, particularly in cases of a contralateral CA occlusion.

16.
Sci Rep ; 14(1): 12325, 2024 05 29.
Artículo en Inglés | MEDLINE | ID: mdl-38811621

RESUMEN

Knowledge of thrombus behavior and visualization on MRI in acute ischemic stroke is less than optimal. However, MRI sequences could be enhanced based on the typical T1 and T2 relaxation times of the target tissues, which mainly determine their signal intensities on imaging. We studied the relaxation times of a broad spectrum of clot analogs along with their image characteristics of three sequences analyzed: a T1-weighted turbo inversion-recovery sequence (T1w Turbo IR), a T1-weighted turbo spin echo with fat suppression (T1w TSE SPIR), and a T2-weighted 3D TSE with magnetization refocusing to remove T1 dependence (T2w TSE DRIVE). We compared their imaging behavior with the intensity values of normal brain tissue using the same imaging protocols as for clots. Each histological and biochemical clot component contributed to each of the relaxation times. Overall, histological composition correlated strongly with T1 times, and iron content, specifically, with T2 relaxation time. Using decision trees, fibrin content was selected as the primary biomarker for T1 relaxation times, inducing an increase. Up to four clot subgroups could be defined based on its distinctive T1 relaxation time. Clot signal intensity in the T1 and T2-weighted images varied significantly according to T1 and T2 relaxation times. Moreover, in comparison with normal brain tissue intensity values, T2w DRIVE images depict thrombi according to the principle of the more fibrin, the higher the intensity, and in T1w TSE, the more erythrocytes, the higher the intensity. These findings could facilitate improvements in MRI sequences for clot visualization and indicate that T2w DRIVE and T1w TSE sequences should depict the vast majority of acute ischemic stroke thrombi as more hyperintense than surrounding tissues.


Asunto(s)
Accidente Cerebrovascular Isquémico , Imagen por Resonancia Magnética , Trombosis , Imagen por Resonancia Magnética/métodos , Humanos , Accidente Cerebrovascular Isquémico/diagnóstico por imagen , Accidente Cerebrovascular Isquémico/patología , Trombosis/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Fibrina/metabolismo , Procesamiento de Imagen Asistido por Computador
17.
Ann Hematol ; 92(4): 443-9, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23250622

RESUMEN

In acute promyelocytic leukemia (APL), relapse occurs in about 15 % of cases and is a major cause for death. Molecular markers identifying patients at high risk for relapse are not well established. High expression of the transcription factor Ets-related gene (ERG) is associated with inferior overall survival (OS) and disease-free survival in different types of hematologic malignancies. There are no data available about the impact of ERG expression in APL. ERG expression levels were analyzed in bone marrow samples of 86 APL patients at initial diagnosis. High ERG expression was significantly associated with an inferior OS in patients who had reached first complete remission. It was also significantly correlated with inferior relapse-free survival (RFS) and time to relapse (i.e., relapse-free interval, RFI). In multivariate analysis, high ERG expression had an independent negative impact on RFS and RFI. High ERG expression was significantly associated with inferior OS, RFS, and RFI. Moreover, in multivariate analysis, it maintained its value as an independent negative prognostic factor with regard to RFS and RFI. Therefore, ERG expression might serve as a molecular marker for risk stratification in APL and might identify patients who could benefit from intensified treatment regimens.


Asunto(s)
Biomarcadores de Tumor/genética , Leucemia Promielocítica Aguda/diagnóstico , Leucemia Promielocítica Aguda/genética , Transactivadores/genética , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Supervivencia sin Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Leucemia Promielocítica Aguda/mortalidad , Leucemia Promielocítica Aguda/terapia , Masculino , Persona de Mediana Edad , Pronóstico , Recurrencia , Estudios Retrospectivos , Análisis de Supervivencia , Regulador Transcripcional ERG , Regulación hacia Arriba/genética , Adulto Joven
18.
J Clin Med ; 12(4)2023 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-36835975

RESUMEN

BACKGROUND: The surgical treatment of proximal humeral fractures (PHFs) with locking plate fixation (LPF) in the elderly is associated with high complication rates, especially in osteoporotic bone. Variants of LPF such as additional cerclages, double plating, bone grafting and cement augmentation can be applied. The objective of the study was to describe the extent of their actual use and how this changed over time. METHODS: Retrospective analysis of health claims data of the Federal Association of the Local Health Insurance Funds was performed, covering all patients aged 65 years and older, who had a coded diagnosis of PHF and were treated with LPF between 2010 and 2018. Differences between treatment variants were analyzed (explorative) via chi-squared or Kruskal-Wallis tests. RESULTS: Of the 41,216 treated patients, 32,952 (80%) were treated with LPF only, 5572 (14%) received additional screws or plates, 1983 (5%) received additional augmentations and 709 (2%) received a combination of both. During the study period, relative changes were observed as follows: -35% for LPF only, +58% for LPF with additional fracture fixation and +25% for LPF with additional augmentation. Overall, the intra-hospital complication rate was 15% with differences between the treatment variants (LPF only 15%, LPF with additional fracture fixation 14%, LPF with additional augmentation 19%; p < 0.001), and a 30-day mortality of 2%. CONCLUSIONS: Within an overall decrease of LPF by approximately one-third, there is both an absolute and relative increase of treatment variants. Collectively, they account for 20% of all coded LPFs, which might indicate more personalized treatment pathways. The leading variant was additional fracture fixation using cerclages.

19.
Clin Cancer Res ; 29(24): 5057-5068, 2023 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-37843857

RESUMEN

PURPOSE: The phase III, open-label, prospective, multicenter, randomized Ewing 2008R1 trial (EudraCT2008-003658-13) was conducted in 12 countries to evaluate the effect of zoledronic acid (ZOL) maintenance therapy compared with no add-on regarding event-free survival (EFS, primary endpoint) and overall survival (OS) in standard-risk Ewing sarcoma (EWS). PATIENTS AND METHODS: Eligible patients had localized EWS with either good histologic response to induction chemotherapy and/or small tumors (<200 mL). Patients received six cycles of VIDE induction and eight cycles of VAI (male) or eight cycles of VAC (female) consolidation. ZOL treatment started parallel to the sixth consolidation cycle. Randomization was stratified by tumor site (pelvis/other). The two-sided adaptive inverse-normal four-stage design (planned sample size 448 patients, significance level 5%, power 80%) was changed after the first interim analysis using the Müller-Schäfer method. RESULTS: Between April 2010 and November 2018, 284 patients were randomized (142 ZOL/142 no add-on). With a median follow-up of 3.9 years, EFS was not significantly different between ZOL and no add-on group in the adaptive design (HR, 0.74; 95% CI, 0.43-1.28, P = 0.27, intention-to-treat). Three-year EFS rates were 84.0% (95% CI, 77.7%-90.8%) for ZOL vs. 81.7% (95% CI, 75.2%-88.8%) for no add-on. Results were similar in the per-protocol collective. OS was not different between groups. The 3-year OS was 92.8% (95% CI, 88.4%-97.5%) for ZOL and 94.6% (95% CI, 90.9%-98.6%) for no add-on. Noticeable more renal, neurologic, and gastrointestinal toxicities were observed for ZOL (P < 0.05). Severe renal toxicities occurred more often in the ZOL arm (P = 0.003). CONCLUSIONS: In patients with standard-risk localized EWS, there is no additional benefit from maintenance treatment with ZOL.


Asunto(s)
Neoplasias Óseas , Sarcoma de Ewing , Humanos , Masculino , Femenino , Sarcoma de Ewing/patología , Ácido Zoledrónico/uso terapéutico , Estudios Prospectivos , Supervivencia sin Progresión , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias Óseas/patología
20.
PLoS One ; 17(7): e0271094, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35862473

RESUMEN

The one-sample log-rank test is the method of choice for single-arm Phase II trials with time-to-event endpoint. It allows to compare the survival of patients to a reference survival curve that typically represents the expected survival under standard of care. The one-sample log-rank test, however, assumes that the reference survival curve is known. This ignores that the reference curve is commonly estimated from historic data and thus prone to sampling error. Ignoring sampling variability of the reference curve results in type I error rate inflation. We study this inflation in type I error rate analytically and by simulation. Moreover we derive the actual distribution of the one-sample log-rank test statistic, when the sampling variability of the reference curve is taken into account. In particular, we provide a consistent estimate of the factor by which the true variance of the one-sample log-rank statistic is underestimated when reference curve sampling variability is ignored. Our results are further substantiated by a case study using a real world data example in which we demonstrate how to estimate the error rate inflation in the planning stage of a trial.


Asunto(s)
Proyectos de Investigación , Simulación por Computador , Humanos , Tamaño de la Muestra
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