Complete Regression of Ductal Carcinoma in Situ Following Chemotherapy and Trastuzumab: Should we Rethink Management?

Background: Ductal carcinoma in situ (DCIS) includes comedo-DCIS, which consists of high-grade DCIS associated with dilated ducts filled with intraluminal comedonecrosis.Current consensus opinion is that prognosis is excellent for all forms of DCIS and that no form of DCIS responds to chemotherapy.However, herein we describe a patient who had complete resolution of comedo-DCIS with the combination of paclitaxel, carboplatin and trastuzumab and results of a retrospective analysis that challenge current opinion. Materials and methods:The cancer registry of Hoag Hospital in Newport Beach, California, was used to indentify subset cohorts of patients with DCIS and local-stage invasive breast cancer.Survival curves were compared by the log-rank test.Results: There were 7,373 breast cancer patients diagnosed during 1983-2007 including 205 classified as comedo-DCIS, 1006 as non-comedo-DCIS, 46 as locally invasive comedocarcinoma and 3905 as other types of locally invasive breast cancer.Ninety-eight percent of the comedocarcinoma diagnoses were made prior to 1997.During 1991-2000 comedo-DCIS accounted for 134/505 (26.5%) of all DCIS compared to 61/565 (10.8%) during 2001-2007 (p<0.0001).Patients with comedo-DCIS had a worse overall survival than other DCIS patients (p<0.040),but survival was similar for comedo-DCIS and invasive comedocarcinoma (p=0.62). Conclusion: Neoadjuvant chemotherapy plus trastuzumab can completely eradicateHer2-positive comedo-DCIS.Survival for comedo-DCIS is worse than for noncomedo DCIS and similar to invasive comedocarcinoma.Because of changes in synoptic reporting and current terminology in pathology reports, comedocarcinoma is no longer being documented and the diagnosis of comedo-DCIS has decreased.Additional studies are warranted to determine whether women with large breast lesions that show only comedo-DCIS on biopsy, should be considered candidates for neoadjuvant therapy to facilitate breast-conserving surgery.