Ductal carcinoma in situ (DCIS) of the breast: diagnostic and therapeutic controversies

Abstract

Melvin J Silverstein, MD, FACS: Ductal carcinoma in situ (DCIS) of the breast is a heterogeneous group of lesions with diverse malignant potential and a range of controversial treatment options. It is the most rapidly growing subgroup in the breast cancer family with an estimate of more than 42,000 new cases diagnosed in the United States during 2000. Most new cases are nonpalpable and discovered by mammography. The most contentious issue today is whether or not all patients with DCIS who elect breast preservation require postexcisional radiation therapy. Treatment ranges from simple excision to various forms of wider excision (segmental resection, quadrant resection, etc), all of which may or may not be followed by radiation therapy. If breast preservation is not an option, then mastectomy, with or without immediate reconstruction, is generally performed. Because DCIS is a heterogeneous group of lesions rather than a single entity, and because patients have a wide variety of personal needs that must be considered during treatment selection, it is obvious that no single approach will be appropriate for all forms of the disease or for all patients. At the current time, treatment decisions are based on a variety of measurable parameters (tumor extent, margin width, nuclear grade, comedotype architecture, etc). In other words, our approach to noninvasive breast cancer is phenotypic rather than genotypic. It is based on morphology rather than etiology. Genetic changes routinely precede morphologic evidence of malignant transformation. Using basic science, medicine must learn how to recognize these genetic changes, exploit them, and, ultimately, prevent them. DCIS is a lesion in which the complete malignant phenotype of unlimited growth, angiogenesis, genomic elasticity, invasion, and metastasis has not been fully expressed. With sufficient time, most DCIS lesions will learn how to invade and metastasize. We must learn how to prevent this. On October 24, 2000, in Chicago, at the annual meeting of the American College of Surgeons, a 3-hour symposium exploring the diagnostic and therapeutic controversies of DCIS was held. A typically structured session on DCIS might have covered mammographic appearance, pathologic classification, and surgical treatment. But the organizers wanted this to be a more cutting-edge session. So, controversial topics like minimally invasive breast biopsy and its transition from diagnosis to possible treatment modality were included. Skin-sparing mastectomy and breast conservation without postexcisional radiation therapy were main focuses of discussion, as was the meaning of micrometastases after sentinel node biopsy. Finally, there was a detailed discussion of hormone replacement therapy and the use No competing interests declared.