Controversies in the local management of invasive and non-invasive breast cancer.

Since the recent acceptance of partial mastectomy (lumpectomy or segmentectomy) as equivalent to mastectomy for survival, design of the local management of breast cancers has centered around concerns of local recurrence. There has been wide acceptance of the tumorectomy or lumpectomy approach by most authors in North America, while in Italy, following the Milan trials, there has been a preference for a segmental or quadrantectomy approach. The latter preferentially includes more ductal tissue toward and distant from the nipple and has shown a local recurrence rate less than 50% as great as that seen with lumpectomy. Radiotherapy dosages and techniques are of concern as well. If extensive ductal carcinoma in situ is a determinant of local recurrence, and if DCIS spreads preferentially along ducts in a radial fashion, then the extent of DCIS is most likely to be preferentially arrayed toward the nipple as well as in tissue on the other side of a tumor mass away from the nipple--such has been our knowledge of the ramifications of the ductal tree, in a radial fashion around the nipple. Acceptable cosmesis after a segmental approach to excision may be more difficult to obtain, but has been acceptable in some groups of patients. We may soon see a situation in which the operation is tailored to the specifics of an individual patient. The size of a resection, based on an even margin around a tumor mass (lumpectomy) or the number of degrees subtended by the arc representing the peripheral aspect of a segmental excision will depend on the size of the dominant lesion being resected, the size of the breast and any available data concerning the likely extent of the lesion, with DCIS having a special concern.