Cytologic evaluation of lumpectomy margins in patients with ductal carcinoma in situ: Clinical outcome

Backround: Breast conservation therapy is controversial for ductal carcinoma in situ (DCIS) due to recently reported high recurrence rates. We believe that cytologic evaluation of lumpectomy margins improves efficiency and leads to a lower recurrence rate following lumpectomy for DCIS. Methods: A prospectively accrued database of 1255 breast cancer patients at the H. Lee Moffitt Cancer Center and Research Institute was found to have 218 patients with DCIS (17.4%). Of those 218 cases, 114 were treated with lumpectomy, axillary dissection, and radiation therapy; the remaining 104 patients were treated with mastectomy with or without reconstruction. Imprint cytology was used to evaluate all lumpectomy margins. Permanent sections and imprint cytology were reviewed by the same pathologist. Results: All lumpectomy specimens (116 tumors in 114 patients) were evaluated. The median follow up was 57.5 months (range 2-110 months). One hundred and three patients with 104 tumors were selected on the basis of pure DCIS (with or without microinvasion), and treated with lumpectomy, axillary dissection and radiation therapy, Of the 104 tumors utilizing attempted breast conservation therapy, 7 (6.6%) required mastectomy. There were 6 recurrences (6.1%) with a median time for recurrence of 47.5 months (range 27-85 months): four recurrences were comedo and two were noncomedo at original diagnosis. Conclusions: The determination of lumpectomy margins in DCIS patients using imprint cytology leads to an overall recurrence rate of 6.1% with reduction in operative time, and re-excision rate. Significant recurrence rates were associated with microinvasion and multifocal tumors (28%) versus simple DCIS at 5 years. Breast conservation therapy and surgical margin determination with imprint cytology for DCIS is a cost-effective and reliable method of treatment for simple DCIS.