Clinical significance of S100A7 protein in predicting recurrence of breast cancer in patients undergoing breast-conserving surgery with radiotherapy*

Abstract

Abstract Objective To investigate the relationship between the expression of S100A7 protein and prediction of recurrence and prognosis of breast cancer in patients undergoing breast-conserving surgery combined with radiotherapy. Methods 349 samples of carcinoma tissue wax blocks were selected from January 2011 to January 2014 in Qingdao Central Hospital. All the patients had undergone breast-conserving surgery. We analyzed S100A7 expression in tumor tissue by immunohistochemical staining. Using univariate and multivariate analyses, we evaluated the relationship between S100A7 and clinical results, to explore independent risk factors for local regional recurrence (LRR). Results The positive expression of S100A7 in the recurrence group (66.7%) was significantly higher than in the non-recurrence group (38.4%), P = 0.025. A log-rank test showed that high S100A7 expression was significantly correlated with 5-year regional recurrence free survival rate (RFS) (94.9% vs 89.5%, P = 0.0408), distant metastasis free survival rate (DFS) (95.4% vs 83.5%, P < 0.001), and overall survival rate (OS) (99.0% vs 92.5%, P = 0.0011). Histological grade, vessel carcinoma embolus, lymph node metastasis, S100A7 expression, and tumor size were factors that influenced RFS. Multivariate analysis of the Cox proportional hazard model showed that high S100A7 expression was an independent risk factor that affected breast cancer RFS (HR = 6.864, 95 % CI: 1.575 - 29.915, P = 0.01). Thus, we concluded that high S100A7 expression is associated with increased risk of LRR and distant metastasis of breast cancer after breast-conserving surgery and postoperative radiotherapy. S100A7 can be used as a molecular marker to screen for patients with high recurrence risk after breast-conserving surgery.