Sample size calculation based on efficient unconditional tests for clinical trials with historical controls

Shan, Guogen; Moonie, Sheniz; Shen, Jay J.

doi:10.1080/10543406.2014.1000545

Cited by 12 publications

(6 citation statements)

References 22 publications

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“…Studies have indicated that miR-126-3p is poorly expressed in various tumors, including hepatocellular carcinoma, a finding which was consistent with the results of our study 19 . The downregulation of miR-126-3p has also been flagged in cervical cancer tissues when compared with normal cervical tissues,28, 29, 30 whereas its level in cervical mucus was found to be increased among patients with cervical cancer 31 . Furthermore, decreased miR-126 expression has been previously linked with pancreatic cancer 24, 32.…”

Section: Discussionsupporting

confidence: 92%

RETRACTED: Bone Marrow Mesenchymal Stem Cell-Derived Exosomal MicroRNA-126-3p Inhibits Pancreatic Cancer Development by Targeting ADAM9

Wen

Han

et al. 2019

Molecular Therapy - Nucleic Acids

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Pancreatic cancer is a lethal malignancy with relatively few effective therapies. Recent investigations have highlighted the role of microRNAs (miRNAs) as crucial regulators in various tumor processes including tumor progression. Hence the current study aimed to investigate the role of bone marrow mesenchymal stem cell (BMSC)-derived exosomal microRNA-126-3p (miR-126-3p) in pancreatic cancer. Initially, miRNA candidates and related genes associated with pancreatic cancer were screened. PANC-1 cells were transfected with miR-126-3p or silenced a disintegrin and a metalloproteinase-9 (ADAM9) to examine their regulatory roles in pancreatic cancer cells. Additionally, exosomes derived from BMSCs were isolated and co-cultured with pancreatic cancer cells to elucidate the effects of exosomes in pancreatic cancer. Furthermore, the effects of overexpressed miR-126-3p derived from BMSCs exosomes on proliferation, migration, invasion, apoptosis, tumor growth, and metastasis of pancreatic cancer cells were analyzed in connection with lentiviral packaged miR-126-3p in vivo . Restored miR-126-3p was observed to suppress pancreatic cancer through downregulating ADAM9. Notably, overexpressed miR-126-3p derived from BMSCs exosomes inhibited the proliferation, invasion, and metastasis of pancreatic cancer cells, and promoted their apoptosis both in vitro and in vivo . Taken together, the key findings of the study indicated that overexpressed miR-126-3p derived from BMSCs exosomes inhibited the development of pancreatic cancer through the downregulation of ADAM9, highlighting the potential of miR-126-3p as a novel biomarker for pancreatic cancer treatment.

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Section: Discussionsupporting

confidence: 92%

RETRACTED: Bone Marrow Mesenchymal Stem Cell-Derived Exosomal MicroRNA-126-3p Inhibits Pancreatic Cancer Development by Targeting ADAM9

Wen

Han

et al. 2019

Molecular Therapy - Nucleic Acids

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“…The power of the study will be maximized over all possible critical values for each first stage response by using the branch-and-bound intelligent algorithm. The monotonic ordering the second stage critical value is intuitive and consistent with existing approaches [3, 13, 5, 20, 21, 22, 5, 23, 24]. The power gain of the proposed approach as compared to the KC approach is generally substantial.…”

Section: Discussionsupporting

confidence: 76%

Optimal inference for Simon's two-stage design with over or under enrollment at the second stage

Shan

Chen

2017

Communications in Statistics - Simulation and Computation

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Simon’s two-stage designs are widely used in clinical trials to assess the activity of a new treatment. In practice, it is often the case that the second stage sample size is different from the planned one. For this reason, the critical value for the second stage is no longer valid for statistical inference. Existing approaches for making statistical inference are either based on asymptotic methods or not optimal. We propose an approach to maximize the power of the study while maintaining the type I error rate where the type I error rate and power are calculated exactly from binomial distributions. The critical values of the proposed approach are numerically searched by an intelligent algorithm over the complete parameter space. It is guaranteed that the proposed approach is at least as powerful as the conditional power approach which is a valid but non-optimal approach. The power gain of the proposed approach can be substantial as compared to the conditional power approach. We apply the proposed approach to a real Phase II clinical trial.

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“…As compared to the exact approach for sample size calculation, (Lloyd, 2007, 2014, 2008a; Shan, 2013; Shan, Ma, Hutson, & Wilding, 2012; Shan & Ma, 2016; Shan, 2015; Shan, Wilding, Hutson, & Gerstenberger, 2016; Shan, Moonie, & Shen, 2016; Shan, 2015), the existing GEE approach does not guarantee type I and II error rates although it is computationally easy with a closed form. With the wide availability of powerful computers or supercomputers, exact sample size computation is practical and feasible.…”

Section: Discussionmentioning

confidence: 99%

Sample size determination for a matched‐pairs study with incomplete data using exact approach

Shan

Bernick

Banks

2017

Brit J Math & Statis

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This research was motivated by a clinical trial design for a cognitive study. The pilot study was a matched-pairs design where some data are missing, specifically the missing data coming at the end of the study. Existing approaches to determine sample size are all based on asymptotic approaches (e.g., the GEE approach). When the sample size in a clinical trial is small to medium, these asymptotic approaches may not be appropriate for use due to the unsatisfactory type I and II error rates. For this reason, we consider the exact unconditional approach to compute the sample size for a matched-pairs study with incomplete data. Recommendations are made for each possible missing pattern by comparing the exact sample sizes based on three commonly used test statistics, with the existing sample size calculation based on the GEE approach. An example from a real surgeon-reviewers study is used to illustrate the application of the exact sample size calculation in study designs.

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Sample size calculation based on efficient unconditional tests for clinical trials with historical controls

Cited by 12 publications

References 22 publications

RETRACTED: Bone Marrow Mesenchymal Stem Cell-Derived Exosomal MicroRNA-126-3p Inhibits Pancreatic Cancer Development by Targeting ADAM9

RETRACTED: Bone Marrow Mesenchymal Stem Cell-Derived Exosomal MicroRNA-126-3p Inhibits Pancreatic Cancer Development by Targeting ADAM9

Optimal inference for Simon's two-stage design with over or under enrollment at the second stage

Sample size determination for a matched‐pairs study with incomplete data using exact approach

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