Abstract: | From 20-year follow-up results of two pioneering randomized controlled trials demonstrating equal survival after mastectomy and breast-conservation therapy, recent high-quality, evidence-based clinical practice recommendations have been made. Breast-conservation therapy undoubtedly represents substantial progress for a better quality of life for women with early-stage breast cancer. However, lumpectomy is associated with a substantial proportion, approximately 10–20%, of local recurrence in long-term follow-up studies even after accounting for postoperative radiotherapy. Risk factors for local failure include margin status, young age and an extensive intraductal component. Young age and family history strongly suggest the need for genetic testing before initiation of treatment. Women with BRCA1 or BRCA2 mutations should be informed about the increased risk of contralateral breast cancer and ipsilateral failure after breast-conservation therapy. Bilateral mastectomy should also be offered as a treatment option. There is controversy over whether current effective adjuvant treatment, including chemotherapy and endocrine therapy, beyond appropriate local treatment as surgery and radiotherapy, can improve local control. Instead of debate over whether an ipsilateral tumor after breast-conservation therapy is local recurrence or a new primary cancer by analyzing conflicting data lacking strong evidence, efforts should be focused on reducing this risk irrespective of origin. Selecting women for breast-conservation therapy and achieving margin control can reduce ipsilateral failures. |