Combined Detection of CK5/6, CK14 and EGFR in Diagnosis of Basal-like Subtype Triple Negative Breast Cancer

    Objective       To investigate the value of combined detection of CK5/6, CK14 and epidermal growth factor receptor (EGFR) in diagnosing basal-like subtype triple negative breast cancer (TNBC).

    Methods       The clinical and pathological data of 115 patients diagnosed with TNBC were recorded from January 2000 to December 2011. The expression of CK5/6, CK14 and EGFR were detected with immunohistochemical methods using paraffin specimens. Combined detection result of the three markers was used as gold standard, then the sensitivity and specificity of CK5/6, CK14 and EGFR were detected by single marker and two combined assays.The differences between basal-like and non basal-like subtype TNBC in age, tumor size, tumor histological type and other clinicopathological issues were compared.

    Results       The mean age of 115 patients with TNBC was (50.7±13.6) years. Immunhistochemical result showed that single marker positivity was 29.6% (34/115), 21.7% (18/83), and 60.9% (70/115) for CK5/6, CK14, and EGFR, respectively. Combined detection of the three markers, the positive rate was 67.8% (78/115). Taking three markers combination as a golden standard, the sensitivity and specificity of EGFR and CK5/6 combination were 98.7% and 100%. There were significant differences between basal-like and non basal-like subtype TNBC in histological type, tumor grade, lymph node metastasis and mortality(all P < 0.05). Survival analysis showed that the overall survival period of basal-like subtype TNBC was significant shortened(HR=0.363, 95% CI:0.139~0.947).

    Conclusions       Combined detection of CK5/6, CK14 and EGFR could identifiy the largest number of basal-like subtype TNBC. The prognosis of basal-like subtype TNBC is worse than that of non basal-like subtype TNBC, and it is important to identify the subtype.