Expression of high-molecular-weight cytokeratin (34betaE12) is an independent predictor of disease-free survival in patients with triple-negative tumours of the breast.

One-fifth of breast cancers have the triple-negative phenotype; a good prognostic marker has yet not been described for these tumours. Tumour microarrays from 58 triple-negative patients treated with surgery followed by chemotherapy were analysed for expression of cytokeratin 5/6 (CK5/6), epidermal growth factor receptor (EGFR), vimentin, p63 and cytokeratin 34betaE12. The mean patient age was 59.2 years with a follow-up from 39 to 168 months. Clinicopathological variables and survival data were correlated with biomarker expression. The frequency of expression of cytokeratin 5/6, EGFR, vimentin, p63 and 34betaE12 was 33%, 65%, 50%, 19% and 85%, respectively. Each of 34betaE12, p63, EGFR and T stage significantly correlated with both disease-free survival and overall survival. T stage and 34betaE12 were independent predictors of overall survival in a multivariate analysis. Expression of 34betaE12 predicts disease-free and overall survival in patients with triple-negative tumours. Additional studies are planned to confirm these initial findings.