Correlation of sex‐determining region Y‐box 30 with tumor characteristics and its prognostic value in breast cancer

OBJECTIVE: Sex‐determining region Y‐box 30 (SOX30) suppresses progression of several cancers, whereas its role in breast cancer is unclear. Therefore, we aimed to determine the correlation of SOX30 with tumor characteristics and prognosis in breast cancer patients. METHODS: The tumor samples of 510 breast cancer patients who underwent resection were obtained, and SOX30 expression was analyzed by immunohistochemistry. Clinical characteristics, disease‐free survival (DFS), and overall survival (OS) of breast cancer patients were recorded. RESULTS: There were 368 breast cancer patients in SOX30 low‐expression group and 142 in SOX30 high‐expression group. SOX30 was negatively correlated with tumor size (P = .010), tumor (T) stage (P < .001), node (N) stage (P = .001), and tumor, node, metastasis (TNM) stage (P < .001) in breast cancer patients. For prognosis, patients in SOX30 high‐expression group had prolonged DFS (P = .011) and OS (P = .002); moreover, increased SOX30 grade (assessed by semi‐quantitative scoring method assessment) was correlated with better DFS (P = .015) and OS (P = .014). Univariate Cox's regression analysis disclosed that SOX30 high expression was correlated with enhanced DFS (P = .012, hazard ratio (HR) = 0.582) and OS (P = .002, HR = 0.389); however, multivariate Cox's regression analysis revealed that SOX30 could not independently predict DFS (P = .224, HR = 0.766) or OS (P = .087, HR = 0.582) in breast cancer patients, indicating it might interact with other independent predictive factors (such as pathological differentiation, T stage, and N stage) to influence DFS and OS in breast cancer patients. CONCLUSION: Sex‐determining region Y‐box 30 is a potential prognostic biomarker in breast cancer, which might contribute to the better outcome of breast cancer patients.