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. 

• 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.
• NCT05607004: (Z)-Endoxifen for the Treatment of Premenopausal Women With ER+/​HER2- Breast Cancer (EVANGELINE). This study is looking at drug called (Z)-endoxifen as a possible treatment for pre-menopausal women with ER+/HER2- breast cancer. (Z)-endoxifen is a type of hormone therapy that blocks the body's natural estrogen from binding to cancer cells.
• NCT04584255: Treating Early-Stage HER2-Negative Breast Cancer with a PARP Inhibitor (Niraparib) and Immunotherapy (Dostarlimab) in People with a BRCA or PALB2 Mutation. This study will look at how well the drugs Niraparib (a PARP inhibitor) and Dostarlimab (an immunotherapy) treat early-stage breast cancer in people with an inherited BRCA1, BRCA2 or PALB2 mutation.  
• 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.
• NCT04567420: DNA-Guided Second Line Adjuvant Therapy For High Residual Risk, Stage II-III, Hormone Receptor Positive, HER2 Negative Breast Cancer. This study will monitor people with early-stage, high-risk breast cancer for possible recurrence using a test called circulating tumor DNA (ctDNA). People who test positive for ctDNA but who have no other signs of recurrence, will receive either the drugs palbociclib combined with fulvestrant or standard-of-care adjuvant hormone therapy.

• 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.