Expression of 34 beta E12 may be an independent predictor of survival in breast cancer

Objectives: To investigate the relationship between high-molecular-weight cytokeratin (34 beta E12) and clinicopathological parameters (including HER-2, Ki67 and steroid receptors) in breast cancer to determine its usefulness as a prognostic marker. Methods: In this retrospective study, the expression level 34 beta E12 was assessed in surgically resected breast cancer specimens by immunohistochemical staining. Data were correlated with the patients' clinicopathological parameters. Results: Of the 348 breast cancer tissue samples, 232 (67%) showed positive expression of 34 beta E12. There were statistically significant differences between the positive and negative 34 beta E12 expression groups in tumour size, lymph node involvement, oestrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2) status. There were no differences between groups in age, tumour grade, or Ki67 status. In addition, patients who were positive for 34 beta E12 had significantly extended overall survival. In multivariate analysis, the expression level of 34 beta E12 was found to be a significant independent prognostic factor. Conclusion: These results suggest that positive 34 beta E12 expression is associated with a favourable outcome in breast cancer and so may be a useful prognostic factor. Further studies are required to confirm these results.