Clinical trial NCT03948568: Evaluating Optimal Timing of Endocrine Therapy and Radiation Therapy in Early-stage Breast Cancer (REaCT-RETT)
Official title: A Pragmatic Randomised, Multicentre Trial Evaluating Optimal Timing of Endocrine Therapy and Radiation Therapy in Early-stage Breast Cancer (REaCT-RETT)
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Early-stage Breast Cancer
Keywords: Radiation Therapy
Endocrine Therapy
Lead sponsor: Ottawa Hospital Research Institute
Sponsor class: OTHER
First posted: 2019-05-14
Enrollment: 262
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: REaCT-RETT will demonstrate the non-inferiority of concurrent compared to sequential endocrine therapy in patients receiving post-operative radiotherapy for early stage breast cancer.

Detailed description: Clinical equipoise exists around the optimal time to start adjuvant endocrine therapy in patients who will receive post-operative radiotherapy for breast cancer. Patients receive either concurrent or sequential endocrine and radiation therapy, where concurrent therapy consists of endocrine therapy started before, with or during radiotherapy, while sequential treatment is defined as endocrine therapy starting after the completion of radiotherapy. A recent survey of Canadian oncologists showed that the main reason for prescribing sequential endocrine therapy was a concern that concurrent endocrine therapy and radiotherapy would worsen the toxicity of endocrine treatment. This is despite the absence of any clinical trial evidence to support this. Indeed, a recent systematic review by our group was unable to confirm or refute whether increased toxicities, related to the timing of endocrine therapy and radiotherapy actually exist in clinical practice. The investigators are therefore proposing a pragmatic randomised trial to assess whether or not concurrent endocrine therapy and radiotherapy worsens endocrine treatment-related symptoms in an era of modern endocrine and radiation therapy.

Eligibility criteria: Inclusion Criteria:

* Patients with newly diagnosed early stage, hormone receptor positive breast cancer
* Planned to receive both endocrine therapy and post-operative radiotherapy
* Able to provide verbal consent

Exclusion Criteria:

* Previous endocrine therapy for invasive breast cancer
* Previous radiotherapy for breast cancer in the same breast

Primary outcomes:
measure: Endocrine toxicity
timeFrame: 12 months (+/- 2 weeks) post final fraction of radiotherapy
Secondary outcomes:
measure: Radiotherapy toxicity
timeFrame: 12 months (+/- 2 weeks) post final fraction of radiotherapy
measure: Rates of starting endocrine therapy and compliance
timeFrame: 12 months (+/- 2 weeks) post final fraction of radiotherapy
measure: Direct Estimation of Health Utility Values
timeFrame: 12 months (+/- 2 weeks) post final fraction of radiotherapy
measure: Incremental cost-effectiveness ratios
timeFrame: 12 months (+/- 2 weeks) post final fraction of radiotherapy
measure: Exploratory analyses on evaluating radiotherapy toxicity
timeFrame: 12 months (+/- 2 weeks) post final fraction of radiotherapy
Other outcomes:
Locations:
city: Ottawa
country: Canada
facility: Ottawa Hospital Research Institute
state: Ontario
Study officials:
affiliation: Ottawa Hospital Research Institute
name: Jean Marc Bourque, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: Ottawa Hospital Research Institute
name: Sharon McGee, MD
role: PRINCIPAL_INVESTIGATOR
References: