ESTRO 2024 - Abstract Book

S727

Clinical - Breast

ESTRO 2024

3219

Digital Poster

Rethinking Pragmatic Breast Clinical Trials in a New Era

Jean-Marc Bourque 1 , mark Clemons 2 , Jean-Michel Caudrelier 3 , Michelle Liu 4 , Lisa Vandermeer 4 , Lesley Fallowfield 5 , Sharon McGee 2 1 Centre Hospitalier Universite de Montreal (CHUM), Radiation Oncology, Montreal, Canada. 2 The Ottawa Hospital Cancer Centre, Medical Oncology, Ottawa, Canada. 3 The Ottawa Hospital Cancer Centre, Radiation Oncology, Ottawa, Canada. 4 Cancer Therapeutics Program, The Ottawa Hospital Research Institute, Ottawa, Canada. 5 University of Sussex, Brighton & Sussex Medical School, Falmer, United Kingdom

Purpose/Objective:

Conventional clinical trial designs have historically relied on established methodologies to assess endpoints related to quality of life and toxicity. Recent global challenges, such as the COVID-19 pandemic, have necessitated a reevaluation of traditional practices due to the transition to virtual care and resource limitations in clinical research. In this evolving landscape, the importance of pragmatic clinical trial designs has grown, particularly as they focus on comparative effectiveness research to evaluate the safety and efficacy of therapeutic interventions in a cost effective manner. This study aimed to conduct an audit assessing the performance of different validated Quality-of Life (QOL) surveys and radiation toxicity tools in the context of breast cancer research, within this changing paradigm.

Material/Methods:

An audit was carried out in the context of a multicenter trial that randomized patients to receive adjuvant endocrine therapy either concurrently with or sequentially to radiotherapy. The primary outcome measure in this pragmatic trial was the change in endocrine therapy toxicity between the two groups, with secondary endpoints encompassing QOL (FACT-B, FACT-ES, FACT-G, EQ-5D-5L) and radiation toxicity (CTCAE5).

Results:

A total of 260 patients were randomized between September 2019 and January 2021. Response rates for trial questionnaires and assessments at all study endpoints (baseline, end of radiation, 3, 6, and 12 months post RT) were evaluated. In response to the pandemic, adaptations were made, including the shift to phone and email administration of QOL surveys, resulting in increased compliance with data entry to meet study endpoints. Consequently, the overall completion rates for endocrine therapy toxicity and QOL questionnaires (FACT-B/ES and EQ-5D-5L) at 3 months post RT exceeded 79% (206/260) and remained high at other timepoints. This enabled the study to reach its target sample size for statistical significance. Conversely, assessments of radiation toxicity and cosmesis, which required physical breast exams (CTCAE5), were not adapted and were negatively affected by the transition to virtual care, resulting in less than 50% availability at the end of radiation and at 3- and 6-months post RT. Ultimately, 59% of assessments were insufficient to accurately evaluate differences in radiation toxicity at specific time points at the conclusion of the study.