Wnt7a Deficiency Could Predict Worse Disease-Free and Overall Survival in Estrogen Receptor-Positive Breast Cancer

Purpose: Wnt7a is a glycoprotein involved in embryonic development and the progression of different types of malignant tumors. This study aimed to detect the level of Wnt7a expression in breast cancer and explore its role in the disease progression and prognosis. Methods: A total of 258 patients diagnosed with invasive ductal carcinoma of the breast were included in this study. Using tissue microarray and immunohistochemical staining, we evaluated the association between Wnt7a expression and clinicopathological parameters, and the prognostic value of Wnt7a. Results: Wnt7a expression was significantly correlated with estrogen receptor (ER) expression (odds ratio, 3.95; 95% confidence interval [CI], 1.99-7.80; p<0.001). On univariate and multivariate analyses, loss of Wnt7a expression was associated with poor disease-free survival (DFS) (multivariate hazard ratio [HR], 9.12; 95% CI, 1.80-46.09; p=0.008), but not with poor overall survival (OS). In the ER-positive group (n=114), loss of Wnt7a expression was an independent prognostic factor for shorter DFS (multivariate HR, 13.54; 95% CI, 1.11-165.73; p=0.042) and OS (multivariate HR, 4.76; 95% CI, 1.29-17.61; p=0.019) on univariate and multivariate analyses. However, in the ER-negative group, there was no significant difference in DFS and OS according to Wnt7a expression. Conclusion: The loss of Wnt7a expression might be a meaningful factor in assessing DFS and OS, especially in ER-positive breast cancer.