Is there a role for postmastectomy radiation therapy in ductal carcinoma in situ?

Background. DCIS treated by mastectomy ensures high local control rates. There is limited data on risk for relapse and lack of clear indication for adjuvant radiation therapy (RT). We report a retrospective review on a population of DCIS patients treated with mastectomy. The objective was to identify the overall incidence of relapse, risk factors for local recurrence, and accordingly for whom adjuvant postmastectomy RT may be considered. Methods. This is an IRB-approved retrospective study on a prospective breast cancer database. From 1997 to 2007, we identified 969 patients with diagnoses of DCIS, among them 211 breasts in 207 patients were treated with mastectomy and comprise the study group. Results. With a median followup of 55 months (4.6 years) the 10-year relapse-free survival is 97%. Two of 211 breasts (0.9%) treated with mastectomy developed a local-regional recurrence. Both the relapses were among patients defined as having <1 mm final mastectomy margin. Conclusions. The rare local relapse after mastectomy limits our ability to reliably identify risk factors for relapse. The consideration for postmastectomy RT should be based on an individualized risk evaluating surgical technique used, presence of BRCA mutation, grade and extent of tumor, and proximity of lesion to the margin of resection.

George Peters Award: How does breast-specific gamma imaging affect the management of patients with newly diagnosed breast cancer?

BACKGROUND: We sought to determine the number of patients with known breast cancer who were found to have an additional, mammographically occult lesion detected on breast-specific gamma imaging (BSGI). METHODS: An institutional review board-approved review of all patients who underwent BSGI at Beth Israel Medical Center from 2006 to 2008 was performed. RESULTS: A total of 82 patients underwent BSGI for newly diagnosed breast cancer. Of these, 18 had an additional abnormality, and 17 were biopsied. There were 4 cases of invasive ductal carcinoma, 1 invasive lobular carcinoma, 1 ductal carcinoma in situ, 1 lobular carcinoma in situ, 2 papillomas, and 8 benign biopsies. One patient proceeded directly to mastectomy and an area of ductal carcinoma in situ was found, corresponding to the BSGI. CONCLUSIONS: In our study group, 22% of patients had a surgical change in management based on BSGI findings. BSGI detected additional carcinoma in 9%. BSGI plays an important role in the clinical management of patients with known breast cancer.