The Integration of Conservative Surgery and Radiation for Stage I-II Breast Cancer with Adjuvant Systemic Therapy

: The timing of radiation with adjuvant systemic therapy in patients with stage I-II breast cancer treated with breast-conservation therapy may impact on ipsilateral breast recurrence rates, cosmesis, and complications. Delays to the initiation of radiation of more than 4 months result in breast recurrence rates of 20-25% at 5 years in patients with close or positive margins of resection. Patients with negative margins of resection do not have an increased risk of breast recurrence with delays to the initiation of radiation of 4-6 months. The concurrent use of tamoxifen and radiation has not resulted in an increased risk of breast recurrence; however, patients treated in this manner may experience more acute reactions during radiation, including breast edema and erythema. Symptomatic pneumonitis is more frequent in patients receiving concurrent chemotherapy with methotrexate and radiation to the breast and regional nodes. A higher incidence of arm edema, rib fractures, and cardiac events has been reported in patients receiving radiation and chemotherapy. Cosmesis may be adversely affected by the concurrent use of chemotherapy with methotrexate or tamoxifen during radiation. The optimal sequencing of radiation and adjuvant systemic therapy requires further study.