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 studies are 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 will be a large-scale, population-based, prospective registry. All patients with stage 1-3 breast cancer who receive MammaPrint and BluePrint testing on a primary breast tumor are eligible for this registry.
• NCT05607004: (Z)-Endoxifen for the Treatment of Premenopausal Women With ER+/​HER2- Breast Cancer (EVANGELINE). This study looks at the drug (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 looks at how well the PARP inhibitor niraparib and the immunotherapy drug dostarlimab 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 study evaluates a genomic analysis called Predictor Analysis of Microarray 50 (PAM50, by Prosigna®) as a tool that guides participants and treating physicians for 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 monitors 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 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. 

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