ArticleTrials2019
Follow up after sample size re-estimation in a breast cancer randomized trial for disease-free survival.
Article in Trials, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT00201851 (Phase III Randomized Study of Immediate Versus Luteal Phase Adjuvant Oophorectomy and Tamoxifen in Premenopausal Women With Hormone Receptor-positive Breast Cancer), which is not on this map. Cited by 3 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Phase III Randomized Study of Immediate Versus Luteal Phase Adjuvant Oophorectomy and Tamoxifen in Premenopausal Women With Hormone Receptor-positive Breast Cancer
Who cites it
3 citing papers in PubMed, 3 citations in OpenAlex.
- Blinded-Into-Unblinded Interim Analyses for Clinical Trials With Time-to-Event Endpoints.Biometrical journal. Biometrische Zeitschrift · 2026Article
- Application of sample size re-estimation in clinical trials: A systematic review.Contemporary clinical trials communications · 2023Article
- Adding flexibility to clinical trial designs: an example-based guide to the practical use of adaptive designs.BMC medicine · 2020Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors at 2 institutions in 1 country.
Funding
Abstract
backgroundWhile the clinical trials and statistical methodology literature on sample size re-estimation (SSRE) is robust, evaluation of SSRE procedures following the completion of a clinical trial has been sparsely reported. In blinded sample size re-estimation, only nuisance parameters are re-estimated, and the blinding of the current trial treatment effect is preserved. Blinded re-estimation procedures are well-accepted by regulatory agencies and funders. We review our experience of sample size re-estimation in a large international, National Institutes of Health funded clinical trial for adjuvant breast cancer treatment, and evaluate our blinded sample size re-estimation procedure for this time-to-event trial. We evaluated the SSRE procedure by examining assumptions made during the re-estimation process, estimates resulting from re-estimation, and the impact on final trial results with and without the addition of participants, following sample size re-estimation.
methodsWe compared the control group failure probabilities estimated at the time of SSRE to estimates used in the original planning, to the final un-blinded control group failure probability estimates for those included in the SSRE procedure (SSRE cohort), and to the final total control group failure probability estimates. The impact of re-estimation on the final comparison between randomized treatment groups is evaluated for those in the originally planned cohort (n = 340) and for the combination of those recruited in the originally planned cohort and those added after re-estimation (n = 509).
resultsVery little difference is observed between the originally planned cohort and all randomized patients in the control group failure probabilities over time or in the overall hazard ratio estimating treatment effect (originally planned cohort HR 1.25 (0.86, 1.79); all randomized cohort HR 1.24 95% CI (0.91, 1.68)). At the time of blinded SSRE, the estimated control group failure probabilities at 3 years (0.24) and 5 years (0.40) were similar to those for the SSRE cohort once un-blinded (3 years, 0.22 (0.16, 0.30); 5 years, 0.33 (0.26, 0.41)).
conclusionsWe found that our re-estimation procedure performed reasonably well in estimating the control group failure probabilities at the time of re-estimation. Particularly for time-to-event outcomes, pre-planned blinded SSRE procedures may be the best option to aid in maintaining power.
trial registrationClinicalTrials.gov, NCT00201851 . Registered on 9 September 2005. Retrospectively registered.
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Registered trials
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