Noninvasive Breast Cancer Breast cancer develops as a series of molecular changes in the epithelial cells that lead to ever more malignant behavior. Increased use of mammography has led to more frequent diagnosis of noninvasive breast cancer. These lesions fall into two groups: ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (lobular neoplasia). The management of both entities is controversial. Ductal Carcinoma In Situ (DCIS) Proliferation of cytologically malignant breast epithelial cells within the ducts is termed DCIS. Atypical hyperplasia may be difficult to differentiate from DCIS. At least one-third of patients with untreated DCIS develop invasive breast cancer. | Chapter 086. Breast Cancer Part 12 Noninvasive Breast Cancer Breast cancer develops as a series of molecular changes in the epithelial cells that lead to ever more malignant behavior. Increased use of mammography has led to more frequent diagnosis of noninvasive breast cancer. These lesions fall into two groups ductal carcinoma in situ DCIS and lobular carcinoma in situ lobular neoplasia . The management of both entities is controversial. Ductal Carcinoma In Situ DCIS Proliferation of cytologically malignant breast epithelial cells within the ducts is termed DCIS. Atypical hyperplasia may be difficult to differentiate from DCIS. At least one-third of patients with untreated DCIS develop invasive breast cancer within 5 years. For many years the standard treatment for this disease was mastectomy. However treatment of this condition by lumpectomy and radiation therapy gives survival that is as good as the survival for invasive breast cancer treated by mastectomy. In one randomized trial the combination of wide excision plus irradiation for DCIS caused a substantial reduction in the local recurrence rate as compared with wide excision alone with negative margins though survival was identical in the two arms. No studies have compared either of these regimens to mastectomy. Addition of tamoxifen to any DCIS surgical radiation therapy regimen further improves local control. Data for aromatase inhibitors in this setting are not available. Several prognostic features may help to identify patients at high risk for local recurrence after either lumpectomy alone or lumpectomy with radiation therapy. These include extensive disease age 40 and cytologic features such as necrosis poor nuclear grade and comedo subtype with overexpression of erbB2. Some data suggest that adequate excision with careful determination of pathologically clear margins is associated with a low recurrence rate. When surgery is combined with radiation therapy recurrence which is usually in the same .
