The past 40 years have brought dramatic changes in breast cancer treatments, resulting in a 30% reduction in breast cancer mortality. This is largely the result of new concepts tested in a steady stream of large, well-designed, coordinated clinical trials. Early trials showed that extended surgery ("local therapy") does not improve mortality over less aggressive surgery. Trials conducted in the 1970s and 1980s clearly showed that radical surgery involving removal of the breast provides no outcome advantage over breast-conserving therapy (BCT). One concern with BCT has been a higher rate of local recurrence compared with mastectomy, with initial studies before the routine use of systemic therapy reporting rates of 10% to 20% with BCT. Modern series define a risk of local recurrence after BCT of 2% to 5%, about the same as with mastectomy. The improvement is partly due to improved standards in surgery, radiation oncology, and pathology. However, it is primarily due to the use of systemic endocrine and chemotherapy. BCT is appropriate for most women with breast cancer. This article explores the advancements in breast surgery over the past 10 years.