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

Multiple neoadjuvant endocrine trials demonstrate that women with good prognosis tumors can be identified. These trials have also demonstrated that there are not adverse effects on overall outcome if women are treated with neoadjuvant endocrine therapy for several months prior to definitive treatment. A new standard of care needs to be defined for elderly women with good prognosis estrogen receptor (ER)+ tumors, since these women may benefit from endocrine therapy alone to treat their cancer without compromising local and distant control. The investigators hypothesize that endocrine therapy alone provides adequate local and systemic control of breast cancer in a subpopulation of women 70 or older with ER+ breast cancer and low Ki67 scores.