scholarly journals Leveraging marginal structural modeling with Cox regression to assess the survival benefit of accepting versus declining kidney allograft offers

2019 ◽  
Author(s):  
Jordana B. Cohen ◽  
Vishnu Potluri ◽  
Paige M. Porrett ◽  
Ruohui Chen ◽  
Marielle Roselli ◽  
...  
Keyword(s):  
Survival Benefit ◽  
Cox Regression ◽  
Structural Modeling ◽  
Kidney Allograft ◽  
Marginal Structural Modeling

scholarly journals Serum alpha-fetoprotein and clinical outcomes in patients with advanced hepatocellular carcinoma treated with ramucirumab

2021 ◽  
Author(s):  
Andrew X. Zhu ◽  
Richard S. Finn ◽  
Yoon-Koo Kang ◽  
Chia-Jui Yen ◽  
Peter R. Galle ◽  
...  
Keyword(s):  
Prognostic Factor ◽  
Clinical Outcomes ◽  
Predictive Value ◽  
Survival Benefit ◽  
Radiographic Progression ◽  
Cox Regression ◽  
Selection Criterion ◽  
Alpha Fetoprotein ◽  
Advanced Hepatocellular Carcinoma ◽  
Clinical Trial Registration

Abstract Background Post hoc analyses assessed the prognostic and predictive value of baseline alpha-fetoprotein (AFP), as well as clinical outcomes by AFP response or progression, during treatment in two placebo-controlled trials (REACH, REACH-2). Methods Serum AFP was measured at baseline and every three cycles. The prognostic and predictive value of baseline AFP was assessed by Cox regression models and Subpopulation Treatment Effect Pattern Plot method. Associations between AFP (≥ 20% increase) and radiographic progression and efficacy were assessed. Results Baseline AFP was confirmed as a continuous (REACH, REACH-2; p < 0.0001) and dichotomous (≥400 vs. <400 ng/ml; REACH, p < 0.01) prognostic factor, and was predictive for ramucirumab survival benefit in REACH (p = 0.0042 continuous; p < 0.0001 dichotomous). Time to AFP (hazard ratio [HR] 0.513; p < 0.0001) and radiographic (HR 0.549; p < 0.0001) progression favoured ramucirumab. Association between AFP and radiographic progression was shown for up to 6 (odds ratio [OR] 5.1; p < 0.0001) and 6–12 weeks (OR 1.8; p = 0.0065). AFP response was higher with ramucirumab vs. placebo (p < 0.0001). Survival was longer in patients with an AFP response than patients without (13.6 vs. 5.6 months, HR 0.451; 95% confidence interval, 0.354–0.574; p < 0.0001). Conclusions AFP is an important prognostic factor and a predictive biomarker for ramucirumab survival benefit. AFP ≥ 400 ng/ml is an appropriate selection criterion for ramucirumab. Clinical Trial Registration ClinicalTrials.gov, REACH (NCT01140347) and REACH-2 (NCT02435433).

scholarly journals Ensemble learning of inverse probability weights for marginal structural modeling in large observational datasets

2014 ◽  
Vol 34 (1) ◽  
pp. 106-117 ◽  
Author(s):  
Susan Gruber ◽  
Roger W. Logan ◽  
Inmaculada Jarrín ◽  
Susana Monge ◽  
Miguel A. Hernán
Keyword(s):  
Ensemble Learning ◽  
Structural Modeling ◽  
Inverse Probability ◽  
Inverse Probability Weights ◽  
Marginal Structural Modeling

Treatment Time or Convection Volume in HDF: What Drives the Reduced Mortality Risk?

2015 ◽  
Vol 40 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Camiel L.M. de Roij van Zuijdewijn ◽  
Menso J. Nubé ◽  
Piet M. ter Wee ◽  
Peter J. Blankestijn ◽  
Renée Lévesque ◽  
...  
Keyword(s):  
Confidence Intervals ◽  
Mortality Risk ◽  
Survival Benefit ◽  
Regression Models ◽  
Cox Regression ◽  
Treatment Time ◽  
High Volume ◽  
P Values ◽  
Hazard Ratios

Background/Aims: Treatment time is associated with survival in hemodialysis (HD) patients and with convection volume in hemodiafiltration (HDF) patients. High-volume HDF is associated with improved survival. Therefore, we investigated whether this survival benefit is explained by treatment time. Methods: Participants were subdivided into four groups: HD and tertiles of convection volume in HDF. Three Cox regression models were fitted to calculate hazard ratios (HRs) for mortality of HDF subgroups versus HD: (1) crude, (2) adjusted for confounders, (3) model 2 plus mean treatment time. As the only difference between the latter models is treatment time, any change in HRs is due to this variable. Results: 114/700 analyzed individuals were treated with high-volume HDF. HRs of high-volume HDF are 0.61, 0.62 and 0.64 in the three models, respectively (p values <0.05). Confidence intervals of models 2 and 3 overlap. Conclusion: The survival benefit of high-volume HDF over HD is independent of treatment time.

scholarly journals Explore association of genes in PDL1/PD1 pathway to radiotherapy survival benefit based on interaction model strategy

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Junjie Shen ◽  
Jingfang Liu ◽  
Huijun Li ◽  
Lu Bai ◽  
Zixuan Du ◽  
...  
Keyword(s):  
Survival Benefit ◽  
Cox Regression ◽  
Strong Association ◽  
Interaction Model ◽  
Expression Level ◽  
Type I ◽  
Strong Positive Correlation ◽  
Type Ii ◽  
Biological Interactions ◽  
Data Set

Abstract Purpose To explore the association of genes in “PD-L1 expression and PD-1 check point pathway in cancer” to radiotherapy survival benefit. Methods and materials Gene expression data and clinical information of cancers were downloaded from TCGA. Radiotherapy survival benefit was defined based on interaction model. Fast backward multivariate Cox regression was performed using stacking multiple interpolation data to identify radio-sensitive (RS) genes. Results Among the 73 genes in PD-L1/PD-1 pathway, we identified 24 RS genes in BRCA data set, 25 RS genes in STAD data set and 20 RS genes in HNSC data set, with some crossover genes. Theoretically, there are two types of RS genes. The expression level of Type I RS genes did not affect patients' overall survival (OS), but when receiving radiotherapy, patients with different expression level of Type I RS genes had varied survival benefit. Oppositely, Type II RS genes affected patients' OS. And when receiving radiotherapy, those with lower OS could benefit a lot. Type II RS genes in BRCA had strong positive correlation and closely biological interactions. When performing cluster analysis using these related Type II RS genes, patients could be divided into RS group and non-RS group in BRCA and METABRIC data sets. Conclusions Our study explored potential radio-sensitive biomarkers of several main cancer types in an important tumor immune checkpoint pathway and revealed a strong association between this pathway and radiotherapy survival benefit. New types of RS genes could be identified based on expanded definition to RS genes.

scholarly journals Survival Benefit of Adjuvant Radiation Therapy for Gastric Cancer following Gastrectomy and Extended Lymphadenectomy

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
R. A. Snyder ◽  
E. T. Castaldo ◽  
C. E. Bailey ◽  
S. E. Phillips ◽  
A. B. Chakravarthy ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Radiation Therapy ◽  
Gastric Adenocarcinoma ◽  
Survival Benefit ◽  
Cox Regression ◽  
Population Based ◽  
Adjuvant Radiation ◽  
Extended Lymphadenectomy ◽  
Factors Affecting ◽  
Gastric Cancer Patients

Purpose. Although randomized trials suggest a survival benefit of adjuvant chemotherapy and radiation therapy (XRT) for gastric adenocarcinoma, its use in patients who undergo an extended lymphadenectomy is less clear. The purpose of this study was to determine if a survival benefit exists in gastric cancer patients who receive adjuvant XRT following resection with extended lymphadenectomy.Methods. The SEER registry was queried for records of patients with resected gastric adenocarcinoma from 1988 to 2007. Multivariable Cox regression models were used to assess independent prognostic factors affecting overall survival (OS) and disease-specific survival (DSS).Results. Of 15,060 patients identified, 3,208 (21%) received adjuvant XRT. Adjuvant XRT was independently associated with improved OS (HR 0.67, CI 0.64–0.71) and DSS (HR 0.69, CI 0.65–0.73) in stages IB through IV (M0). This OS and DSS benefit persisted regardless of the extent of lymphadenectomy. Furthermore, lymphadenectomy with >25 LN resected was associated with improved OS and DSS compared with <15 LN or 15–25 LN.Conclusion. This population-based study shows a survival benefit of adjuvant XRT following gastrectomy that persists in patients who have an extended lymphadenectomy. Furthermore, removal of >25 LNs results in improved OS and DSS compared with patients who have fewer LNs resected.

The Cytochrome P450 3A5 Non-Expressor Kidney Allograft as a Risk Factor for Calcineurin Inhibitor Nephrotoxicity

2018 ◽  
Vol 47 (3) ◽  
pp. 182-190 ◽  
Author(s):  
Suwasin Udomkarnjananun ◽  
Natavudh Townamchai ◽  
Pajaree Chariyavilaskul ◽  
Kroonpong Iampenkhae ◽  
Krit Pongpirul ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Calcineurin Inhibitor ◽  
Cox Regression ◽  
Kidney Tissue ◽  
Acute Rejection Episode ◽  
Genotype 3 ◽  
Kidney Allograft ◽  
Cytochrome P450 3A5 ◽  
Calcineurin Inhibitor Nephrotoxicity ◽  
Donor Genotype

Background: Tacrolimus is mainly metabolized by cytochrome P450 3A5 (CYP3A5), which is expressed in the liver. However, CYP3A5 is also expressed in the kidney tissue and may contribute to local tacrolimus clearance in the kidney allograft. We aimed to evaluate the association between the allograft CYP3A5 genotype and transplant outcomes. Methods: We conducted a retrospective cohort study at the King Chulalongkorn Memorial Hospital, Thailand, comparing 2 groups of donor and recipient CYP3A5 genotypes, the expressor (*1/*1 and *1/*3) and the non-expressor (*3/*3). The primary outcomes were allograft complications including calcineurin inhibitor (CNI) nephrotoxicity and acute rejection episode. Results: Of the 50 enrolled patients, 21 donors were expressors and 29 donors were the non-expressors. Tacrolimus trough concentrations were similar between the 2 genotypes. The incidence of CNI nephrotoxicity was higher in recipients with non-expressor donor genotype compared with the expressor donor genotype (72.4 vs. 33.3%, p = 0.006). CNI nephrotoxicity incidence was not different when recipient’s genotypes were compared. Multivariate analysis from Cox-regression showed a hazard ratio of 3.18 (p = 0.026) for CNI nephrotoxicity in the non-expressor compared with the expressor donor. The recipient CYP3A5 genotypes did not significantly contribute to CNI nephrotoxicity. Kaplan-Meier analysis demonstrated the lowest CNI nephrotoxicity-free survival in recipients with the expressor genotype who received allograft from the non-expressor donors (p = 0.005). Conclusion: In conclusion, our results suggest that donor CYP3A5 non-expressor genotype (*3/*3) is a risk for CNI nephrotoxicity.

scholarly journals Hormonal contraception and HIV acquisition: reanalysis using marginal structural modeling

AIDS ◽  
2010 ◽  
Vol 24 (11) ◽  
pp. 1778-1781 ◽  
Author(s):  
Charles S Morrison ◽  
Pai-Lien Chen ◽  
Cynthia Kwok ◽  
Barbra A Richardson ◽  
Tsungai Chipato ◽  
...  
Keyword(s):  
Hormonal Contraception ◽  
Structural Modeling ◽  
Hiv Acquisition ◽  
Marginal Structural Modeling

scholarly journals High N-Terminal proB-Type Natriuretic Peptide Indicates Elevated Risk of Death after Percutaneous Coronary Intervention Compared to Coronary Artery Bypass Surgery in Patients with Left Ventricular Dysfunction

2019 ◽  
Vol 8 (6) ◽  
pp. 898 ◽  
Author(s):  
Christian Roth ◽  
Matthias Schneider ◽  
Daniel Dalos ◽  
Clemens Gangl ◽  
Christian Toth ◽  
...  
Keyword(s):  
Heart Failure ◽  
Percutaneous Coronary Intervention ◽  
Survival Benefit ◽  
Cox Regression ◽  
Artery Bypass ◽  
Coronary Intervention ◽  
Left Ventricular ◽  
Revascularization Procedure ◽  
Risk Of Death ◽  
Percutaneous Coronary

Background: Reduced left ventricular function (LVF) is a predictor for stent-thrombosis. In advanced heart failure (characterized by high NT-proBNP) with an activated coagulation system, coronary events clinically perceived as sudden death or death from heart failure may be more common in patients treated by percutaneous coronary intervention (PCI) than in patients treated by coronary artery bypass grafting (CABG). Our study analyses (1) if patients with reduced LVF who require coronary revascularization will have a better survival benefit with CABG or PCI, and (2) if the survival benefit is predicted by NT-proBNP. Methods: This observational retrospective study included patients from the coronary catheter laboratory database of the Medical University of Vienna (CCLD-MUW). Multivariate Cox regression analyses were performed to test the hypothesis that there is an interaction in the risk of death between those with lower or elevated NT-proBNP levels and the revascularization procedure (PCI or CABG). The relative risk of PCI compared to CABG as reference was calculated for patients with low and elevated NT-proBNP levels. Results: In the entire study population with 398 patients (340 PCI and 58 CABG) the revascularization procedure had no predictive value. When the revascularization procedure*NTproBNP interaction was forced into the Cox regression model, this term was an independent predictor of death. The relative risk of PCI compared to CABG was similar in patients with lower NT-proBNP—1.01 (95% confidence interval (CI), 0.45–2.24), but was significantly increased in patients with elevated NT-proBNP—1.58 (95% CI, 1.07–2.33). Conclusion: Death is associated to the revascularization procedure, but only in those patients with elevated NT-proBNP levels. NT-proBNP is a predicting factor for the revascularization procedure: elevated levels showed an increased risk of death after PCI compared to CABG, whereas lower levels were associated with a similar risk after both revascularization procedures.

Sign in / Sign up

Export Citation Format

Share Document