Ductal carcinoma in situ of the breast: a surgeon's disease.

When I received my surgical training in the 1960s, breast cancer was a surgical disease. Surgeons made the diagnosis, surgeons treated the patient, and surgeons cured the disease, or so we thought. Our thinking was Halstedian; i.e., anatomical and mechanical. A few extra nodes, another centimeter or two of tissue, and the desired result (cure) would be achieved. Axillary node dissection was thought to be both therapeutic and prognostic and every node was important. By the 1970s, a new paradigm was starting to take hold; i.e., invasive breast cancer was a systemic disease at the time of diagnosis.1,2 Adjuvant chemotherapy was shown to work,3,4 and these results supported the new paradigm. The most likely effector of outcome (life or death) was now the existence of viable micrometastases, not the extent of primary surgery or the subtle technical nuances of the surgical procedure. Surgery took the first step toward becoming adjuvant therapy for invasive breast cancer. In the 1980s, the results of National Surgical Adjuvant Breast and Bowel Protocol (NSABP) B-04 suggested that axillary node dissection was largely prognostic and that it was no longer important to remove every node or to perform a three-level dissection.5 As the surgeon’s curative role with invasive breast cancer was questioned, there was a replacement lesion, i.e., a lesion that could be thought of in Halstedian terms, a lesion that surgeons could cure. Ductal carcinoma in situ (DCIS) of the breast is a proliferation of presumably malignant epithelial cells within the ductolobular system of the breast without evidence by light microscopy of invasion through the basement membrane into the surrounding stroma. I say “presumably,” because not every untreated DCIS lesion will go on to become an invasive breast cancer. Although we consider DCIS to be cancer, it lacks two components of the fully expressed malignant phenotype, i.e., invasion and metastasis.6 It is these defects, along with its distribution, generally within a single ductal system,7,8 that makes DCIS a surgical disease. For most of the 20th century, DCIS was a relatively uncommon lesion, representing less than 1% of all newly diagnosed cases of breast cancer.9 The introduction of high-quality mammography dramatically increased the detection rate. Today, DCIS is the most rapidly growing subtype of breast cancer, with a more than 500% increase in new cases from 1983 to 1992.10 During 1999, there will be an estimated 39,000 new cases of DCIS in the United States, 18% of all new cases of breast cancer.11 In centers that rely on mammography, this percentage could be as high as 30% to 40% or higher. During the last 10 to 15 years and without much warning, physicians have been inundated with a large number of new cases of a disease that, until recently, they knew little about. During the 1960s, DCIS was usually thought of as a single disease with one treatment, i.e., mastectomy. It was known to be a more favorable disease when compared with invasive breast cancer, and most surgeons treated DCIS patients with a modified radical mastectomy rather than the Halsted radical mastectomy, the Received July 15, 1999; accepted August 20, 1999. From the Harold E. and Henrietta C. Lee Breast Center, USC/Norris Cancer Center, University of Southern California, Los Angeles, California. Address correspondence and reprint requests to: Melvin J. Silverstein, MD, USC/Norris Cancer Center, 1441 Eastlake Avenue, Room 7415, Los Angeles, CA 90033; Fax: 323-865-3539; E-mail: melsilver9@aol.com Annals of Surgical Oncology, 6(8):802–810 Published by Lippincott Williams & Wilkins © 1999 The Society of Surgical Oncology, Inc.