All women with breast conservation surgery for ductal carcinoma in situ should have radiation

Abstract

Women today who opt for breast conservation surgery for the treatment of ductal carcinoma in situ (DCIS) elect this treatment over the alternate surgery, that is simple mastectomy. They do so because they perceive that mastectomy, with removal of all of the breast tissue, is too radical a procedure for a diagnosis of non-invasive cancer. But these same women want assurance from their physicians that the breast-conserving surgery will not compromise their prognosis. Since DCIS by definition cannot spread beyond the treated breast at the time of diagnosis, but can return as a local failure, with a risk of invasive cancer in about one of every two local failures, minimizing this recurrent event is an important therapeutic goal. In the transition from treatment of DCIS with mastectomy to breast conservation surgery, several treatment schemas have been identified. The branches in the decisionmaking tree have become numerous over time, with increasing availability of detailed information on the extent of the lesion on imaging, the margin status and width, and other pathology details, and how these factors relate to a patient’s risk of local failure. An increasing knowledge about patient risk factors, such as age at the time of the diagnosis, and how this relates to local control or failure, also must be considered in the decision about the ‘best’ therapy. Finally, what is the impact of available treatment options on both the risk of local failure and the patient’s long-term health? As we have learned over time, breast cancer is a disease with a long natural history. Yet many of the ‘facts’ that we know today about DCIS were not recognized a decade ago, so trying to relate a given prognostic factor to long-term clinical outcome is problematic. An example of this is found in the work of the DCIS Collaborative Group, an informal working group of university hospitals in the USA and in Europe, which have pooled data on patients treated with breast-conservation surgery and radiation, to establish a large data base for the purpose of learning more about this disease. After an extensive central review of pathology material from 172 patients, multivariate analysis identified a significantly higher rate of local failure in patients whose tumors exhibited a nuclear grade of 3 and the histologic features of ‘comedo’ carcinoma, compared with those that did