Clinicopathological significance of Sox2 expression in patients with breast cancer: a meta-analysis

Sex-determining region Y-box protein 2 (Sox2), an embryonic transcription factor located at chromosome 3q26.33, has been frequently demonstrated to be an important prognostic marker for various tumors, including breast cancer. However, its clinicopathological role in breast cancer has not been fully elucidated. To derive a more precise evaluation, we here performed a meta-analysis focusing on the association between Sox2 expression and various clinicopathological characteristics of breast cancer. Relevant publications were identified and retrieved using PubMed, Embase, Cochrane Library, Web of Science, Chinese National Knowledge Infrastructure, and Chinese Biomedical databases. Ten studies with a total of 1713 patients with breast cancer were included in our meta-analysis. Reported odds ratios (OR) and the corresponding 95% confidence intervals (95% CI) were pooled to assess the strengths of the analyzed associations. Our results revealed significant positive associations between Sox2 expression and increased tumor size (pooled OR=2.61, 95% CI=1.91-3.58), histological grade (pooled OR=2.28, 95% CI=1.72-3.03), lymph node metastasis (pooled OR=4.17, 95% CI=1.20-14.45), and the highly aggressive triple-negative phenotype (pooled OR=2.64, 95% CI=1.11-6.29). However, no associations were observed for TNM stage and estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 statuses. Overall, the results of this meta-analysis indicate that Sox2 may be considered as a prognostic marker for breast cancer. More well-designed studies with larger sample sizes are warranted to clarify the prognostic significance of Sox2 in breast cancer.