Abstract P5-12-06: Non-adherence to endocrine therapy is associated with a significant increased risk of local recurrence in women ≥65 years with stage T1N0 breast cancer treated with adjuvant endocrine therapy alone after breast-conserving surgery

Abstract Purpose: Clinical guidelines recommend that for women ≥65 years with stage T1N0 breast cancer (BC) treated with breast-conserving surgery (BCS) that breast RT may be omitted and treatment with ET alone is acceptable. However, population-based studies report that up to two-thirds of women with T1N0 BC do not complete 5 years of ET. The effect of non-adherence to ET on recurrence risks in women treated with ET alone is …