Risk factor for axillary lymph node metastases in microinvasive breast cancer.

Abstract

17 Background: Sentinel lymph node biopsy (SLNB) in patients with ductal carcinoma in situ (DCIS) was controversial. Usually we didn’t SLNB when we performed conserving operation with small sized DCIS. But sometimes we can find DCIS with microinvasive breast cancer (MIC) after operation. Must do reoperation in all patients? We determined the incidence of positive axillary lymph node (ALN) in patients with MIC and the predictive factors of ALN metastases in these patients. Methods: Between July 1989 and December 2008, 9.635 patients had operation on invasive breast cancer in Asan Medical Center. Among these patients 319 patients had MIC. The research conducted on the 293 patients except who didn’t performed axillary lymph node dissection or SLN biopsy. We retrospectively checked clinical and pathologic variables. Results: There were 22 cases of ALN metastases identified in this group of patients (7.5%). Lymphatic invasion (p<0.001) and positive estrogen receptor status (p=0.03) were independent significant predictors of axillary metastases. Conclusions: Microinvasive breast cancer is associated with a low rate of lymph node metastases. Some breast cancer patients with MIC at low likelihood of lymph node metastases may be spared lymph node evaluation.