Immunohistochemical expression of human epidermal growth factor receptor (HER)-4 and prognosis in patients with metastatic breast cancer

Abstract

Purpose: The clinical value of HER4 - a cell surface receptor that belongs to the human epidermal growth factor receptor family - for predicting survival outcomes in patients with breast cancer remains controversial. Herein, we sought to investigate the prognostic significance of HER4 immunohistochemical expression with respect to progression-free survival (PFS) and overall survival (OS) in Turkish patients with metastatic breast cancer (MBC).Methods: MBC patients (N=45; mean age=50.5 +/- 12.7 years) were consecutively enrolled between 2000 and 2006 in the Department of Oncology at the Uludag University Medical Center, Bursa, Turkey. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded sections. The predictive value of HER4 expression was investigated by multivariate analysis after allowance for potential confounders.Results: The mean PFS in the study participants was 11.35 months (range:1-50), whereas the median OS was 22.18 months (range:1-76). The mean PFS in patients with a HER4 immunohistochemical score of 0, 1+, 2+, and 3+ was 11.0 +/- 4.8, 11.3 +/- 7.7, 11.7 +/- 8.1, and 10.4 +/- 7.4 months, respectively (p=0.99). The mean OS in patients with a HER4 score of 0, 1+, 2+, and 3+ was 13.3 +/- 6.8, 25.6 +/- 10.8, 22.9 +/- 10.7, and 13.5 +/- 9.9, months, respectively (p=0.44). The results of multivariate Cox regression analysis indicated that the presence of visceral metastases was the only independent prognostic factor for both OS (HR=3.01, 95% CI=1.56-3.99, p <0.01) and PFS (HR=2.91, 95% CI=1.51-3.78, p <0.01).Conclusion: HER4 immunohistochemical expression is not an independent predictor of OS and PFS in Turkish MBC patients.