EMERALD: Endocrine Therapy oMission With Radiation in ER+ Breast Cancer: Assessing Quality of Life and Disease Control: a Prospective Phase II Trial

Eligibility Criteria

• 1. Diagnosis of pathologically-confirmed invasive breast cancer
• 2. Age ≥ 60 years
• 3. Treatment with breast conserving surgery
• 4. Pathologic T stage of T1 or T2 with total tumor size ≤ 3cm including any component of DCIS that may exist in conjunction with invasive disease
• 5. Ki-67 ≤ 20%
• 6. Final surgical margins negative, defined as no tumor on ink. Lobular carcinoma in situ involving the final surgical margin will be disregarded.
• 7. Tumor must be estrogen receptor positive, progesterone receptor positive and HER2Neu non-amplified as per current College of American Pathologists guidelines
• 8. Clinical nodal stage cN0
• 9. If pathologic nodal staging is obtained, then pN0 or pN0(i+)
• 10. Patients have had or have a scheduled discussion with a breast medical oncologist regarding adjuvant treatment options
• 11. Patients who have met criteria 4.1.1-4.1.9 who never initiate endocrine therapy OR who initiate adjuvant endocrine therapy but discontinue it within 6 months of initiation
• 1. Node positive disease (N1-3)
• 2. Metastatic disease (M1)
• 3. Grade 3 disease and lymphovascular space invasion in the tumor
• 4. Synchronous bilateral breast cancer
• 5. Receipt of neoadjuvant therapy
• 6. Diagnosis of a collagen vascular disease associated with an increased incidence of radiation toxicities such as scleroderma or systemic lupus erythematosis
• 7. Diagnosis of other cancer within the prior 5 years, excluding basal or squamous cell carcinoma of the skin that has been treated
• 8. Patient with psychiatric illness/social situations that would limit compliance with study requirements
• 9. Prior radiotherapy to the index breast or recurrent cancer of the breast
• 10. Known carrier of a mutation associated with predisposition to breast cancer development, including BRCA1 or BRCA2