Some authors have investigated, in a retrospective fashion, the use of routine shave margins, where surgeons routinely take additional margins at the time of the initial partial mastectomy as a means of obtaining negative margins. While these retrospective studies have found that positive margin rates declined using this technique, opponents to this technique wonder if this truly results in a higher negative margin rate without compromising cosmesis or increasing tissue volume removed. As these studies were retrospective, it was possible that the initial resection was smaller than what those who do not routinely take shave margins would resect. No one had evaluated the impact of further resection on operative time, nor in a blinded fashion, evaluated cosmesis. Further, there had yet to be a prospective study to evaluate the impact of this on local recurrence rates. Hence, the investigators performed a prospective randomized controlled trial of this technique at Yale. The data from this study, published in the New England Journal of Medicine, found that the technique cut positive margin and re-excision rates in half. Some wondered, however, about the external generalizability of these findings, particularly in non-academic settings. Hence, a multicenter trial to validate these findings is warranted.