Evaluating Harms and Benefits of Endocrine Therapy in Patients ≥70 Years of Age With Lower Risk Breast Cancer

Official Title

A Randomised, Multicentre Trial Evaluating Harms and Benefits of Endocrine Therapy in Patients ≥70 Years of Age With Lower Risk Breast Cancer (REaCT-70)

Summary:

The current standard of care for stage 1 hormone receptor-positive (HR+) breast cancer consists of breast-conserving surgery followed by adjuvant radiation therapy (RT) and endocrine therapy (ET) for at least 5 years. The benefit of adjuvant ET for older patients is mitigated because of their increase risk of death from other causes and shorter time horizon to live. Clinical and pathological factors such as low-intermediate grade, tumour size ≤2 cm, and older age have been used in a few studies to identify patients with a lower risk of recurrence that might benefit from adjuvant therapy de-escalation, i.e. omission of RT or ET. Since there is no dedicated randomized clinical trial (RCT) conducted to evaluate the omission of ET, there is clinical equipoise as to whether we can omit adjuvant ET in older patients with lower-risk early-stage breast cancer. Therefore, we propose a randomised, multicentre trial evaluating harms and benefits of endocrine therapy in patients ≥70 years of age with lower risk breast cancer.

Trial Description

Primary Outcome:

• Accrual of 100 participants across 8 centres within 2 years
• Participation rate of at least 60%
• 90% treatment allocation rate

Secondary Outcome:

• Significant adverse events
• Endocrine therapy related toxicity
• Health-related quality of life scores
• Rate of treatment discontinuation

The current standard of care for stage 1 hormone receptor-positive (HR+) breast cancer consists of breast-conserving surgery followed by adjuvant radiation therapy (RT) and endocrine therapy (ET) for at least 5 years. The benefit of adjuvant ET for older patients is mitigated because of their increase risk of death from other causes and shorter time horizon to live. This population is also more likely to have additional comorbidities which can lead to higher treatment-related adverse events impacting quality of life and precipitating functional decline. Clinical and pathological factors such as low-intermediate grade, tumour size ≤2 cm, and older age have been used in a few studies to identify patients with a lower risk of recurrence that might benefit from adjuvant therapy de-escalation, i.e. omission of RT or ET. The body of evidence from small prospective studies, mathematical modelling study and retrospective analyses would suggest that the omission of ET in older patients with favourable HR+ breast cancer who had optimal local therapy (i.e. breast conserving surgery followed by adjuvant radiation therapy) does not compromise locoregional and survival outcomes. Since there is no dedicated randomized clinical trial (RCT) conducted to evaluate the omission of ET, there is clinical equipoise as to whether we can omit adjuvant ET in older patients with lower-risk early-stage breast cancer. Therefore, we propose a randomised, multicentre trial evaluating harms and benefits of endocrine therapy in patients ≥70 years of age with lower risk breast cancer.

View this trial on ClinicalTrials.gov