Can We Skip Sentinel Lymph Node Biopsy in Patients Who Have Microinvasive Breast Cancer

Background: Sentinel lymph node(SLN) biopsy in patients with ductal carcinoma in situ(DCIS) was controversial. We may skip SLN biopsy when we performed conserving operation with small sized DCIS. But sometimes we can find DCIS with micro-invasive breast cancer (MIC) after operation. Should another operation be performed? We determined the incidence of positive axillary lymph node (ALNs) in patients with MIC, and the predictive factors of ALNs metastasis in these patients. Methods: Between July 1989 and January 2008, 9046 patients had operations performed on invasive breast cancers at Asan Medical Center. From July1989 to February 2003, ALND was performed to surgically stage the axilla. Since May 2003, SNB has been routinely performed for all cases. Patients who were treated with neoadjuvant chemotherapy and those who had no identifiable ALNs at surgery were excluded from the study. We retrospectively checked clinical and pathologic variables including diagnosis, patient demographics, size of DCIS, grade, multi-focal lesion, hormone receptor status, lymphatic invasion status etc. Results: 265 patients were identified with microinvasive (pathologic stage T1mic) breast cancer. Among these patients, 12 patients didn9t have ALN study. 2 patients had bilateral MIC. The research was conducted on the remaining 255 cases. There were 13 cases of ALN metastases identified in this group of patients(5%). Young age (p=0.006), multifocal lesion (p=0.040) and lymphatic invasion (p Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1019.