Paradoxically, the standard of care for women with early invasive breast cancer is now breast-conserving therapy, but many women with DCIS, particularly with extensive disease, undergo mastectomy. Although DCIS can progress to invasive carcinoma, said Dr. William Wood of Emory University School of Medicine in Atlanta, Georgia, autopsy studies document a prevalence of DCIS that exceeds that of invasive carcinoma, suggesting that some cases do not progress and may therefore be overtreated. Wood stated that the surgical goal of DCIS treatment is to remove the entire tumor and to attempt a 1-cm margin.
Smaller margins are unwise, since the smaller the margin, the higher the risk of local failure.
Local failure is also related to nuclear grade and to age, with younger women associated with the greatest risk of local recurrence. When breast-conserving therapy is performed, postoperative radiation may be necessary to reduce local failure rates. Although axillary staging is not generally recommended for DCIS, sentinel node mapping is currently under investigation. Dr. Wood outlined a 2-step paradigm that can be used for making treatment decisions. Step 1 should focus on tumor size and margins.