Does extending hormonal therapy impact risk of breast cancer recurrence?

Questions To Ask Your Health Care Provider

• Would I benefit from extending hormonal therapy beyond the standard 5 years?
• What are the side effects and toxicity of hormonal therapies like tamoxifen?
• What are the side effects and toxicity of aromatase inhibitors?
• What are the added side effects of extending hormonal therapy beyond 5 years? 

Open Clinical Trials

The following are studies enrolling people with early stage ER-positive, HER2-negative breast cancer. 

• NCT04016935: EndoPredict® Extended Endocrine Trial (EXET). This study is looking at the 5 to 10-year outcomes of patients with hormone receptor-positive, HER2-negative early-stage breast cancer tumors with low EndoPredict® (a tumor test used to predict whether cancer will come back after 10 years) scores who did not continue hormone therapy after 5 years.
• NCT03053193: MammaPrint, BluePrint, and Full-genome Data Linked With Clinical Data to Evaluate New Gene EXpression Profiles (FLEX). The FLEX Registry is a large-scale, population based, prospective registry. All patients with stage I to III breast cancer who receive MammaPrint® and BluePrint testing on a primary breast tumor are eligible for entry into the FLEX Registry.
• NCT04129216: The Effects of Short-term Preoperative Treatment with Hormonal Therapy on Gene Profiles in Breast Cancer. This study is studying how the expression of the Ki-67, estrogen and progesterone receptor genes change after a short course of hormonal therapy before surgery in patients with breast cancer. The goal of this study is to advance personalized treatment for women with breast cancer.
• NCT03749421: Prosigna Assay on Neoadjuvant Clinical Decision-making in Women With HR+/Her2- Breast Cancer. This research study is evaluating a genomic analysis called Predictor Analysis of Microarray 50 (PAM50, by Prosigna®) as a tool to possibly guide the participant and the treating physician to choose the most personalized pre-operative treatment for breast cancer.
• NCT04875351: Breast Cancer Index (BCI) Registry. The purpose of the study is to evaluate long-term clinical outcome, clinical impact, medication adherence and quality of life in hormone receptor positive (HR+) early-stage breast cancer patients receiving BCI testing as part of routine clinical care to inform extended endocrine therapy.
• NCT03725059: Pembrolizumab Versus Placebo With Neoadjuvant Chemotherapy & Adjuvant Endocrine Therapy for Early-Stage Estrogen Receptor-Positive, HER2-Negative Breast Cancer (KEYNOTE-756). This study will assess how well pembrolizumab works compared to placebo in combination with neoadjuvant (pre-surgery) chemotherapy and adjuvant (post-surgery) hormonal therapy in the treatment of high-risk early-stage estrogen receptor-positive, HER2-negative breast cancer.

• NCT04852887: De-Escalation of Breast Radiation Trial for Hormone Sensitive, HER-2 Negative, Oncotype Recurrence Score Less Than or Equal to 18 Breast Cancer (DEBRA). This study evaluates whether breast conservation surgery and endocrine therapy results in a non-inferior rate of invasive or non-invasive ipsilateral breast tumor recurrence (IBTR) compared to breast conservation with breast radiation and endocrine therapy. 

A number of other clinical trials for patients with early-stage breast cancer can be found here.