Endocrine Treatment Alone for Elderly Patients With Estrogen Receptor Positive Operable Breast Cancer and Low Recurrence Score

Inclusion criteria

• Newly diagnosed histologically or cytologically confirmed operable invasive breast cancer defined as cT1 or T2, N0-1, and M0.
• Disease must be ER+ and HER2-.
• Ki67 score/proliferative index ≤ 30% or low to intermediate mitotic index
• Measurable disease defined as lesions that can be accurately measured in at least one dimension (longest diameter to be recorded) by ultrasound or mammogram.
• 70 years of age or older.
• ECOG performance status ≤ 3
• Able to understand and willing to sign an IRB approved written informed consent document (or that of legally authorized representative, if applicable).

Exclusion criteria

• Prior surgery for this cancer
• A history of other malignancy ≤ 5 years previous which would preclude endocrine treatment of their cancer.
• Currently receiving any other investigational agents.
• A history of allergic reactions attributed to compounds of similar chemical or biologic composition to any of the agents used in the study.
• Uncontrolled intercurrent illness as determined by their treating physician which would limit compliance with study requirements.
• Known HIV-positivity on combination antiretroviral therapy because of the potential for pharmacokinetic interactions with endocrine therapies. Appropriate studies will be undertaken in patients receiving combination antiretroviral therapy when indicated.