[Prognostic Value of Basal Marker Expression in Early Stage Breast Cancer]

The expression of basal marker could be a significant factor for poor prognosis in early stage breast cancer. We evaluated the prognostic value of basal marker in each breast cancer subtype. According to immunohistochemistry assay, CK5/6-posi- tive and/or EGFR-positive was defined as basal marker-positive. A total of 497 consecutive, non-metastatic invasive breast cancers were evaluated, and 166 cases(33%)were defined as basal marker-positive. Overall, basal marker expression was not a significant prognostic factor for breast cancer recurrence. However, according to Cox regression analysis, basal markerpositivity was significantly associated with poor recurrence-free survival in 63 cases with TNBC(hazard ratio: 2.9, 95% confidence interval: 1.5-5.8, p=0.001). Therefore, evaluation of basal marker expression could be useful for the risk estimation of recurrence in TNBC.