Prognostic significance of long noncoding RNA Z38 as a candidate biomarker in breast cancer

BACKGROUND: Long noncoding RNA (lncRNA) Z38 has been shown to promote cell proliferation and tumorigenesis in breast cancer. However, expression pattern and prognostic value of lncRNA Z38 in breast cancer patients remain elusive. METHODS: The expression levels of SPRY4-IT1 in 110 self-paired specimens of breast cancer and adjacent normal breast tissues were measured by quantitative real-time PCR (qRT-PCR), and its correlation with overall survival of patients with breast cancer was further statistically analyzed. RESULTS: Compared with normal breast tissues, Z38 was upregulated in breast cancer tissues. Furthermore, of 110 breast cancer patients, high Z38 expression was significantly associated with tumor-node-metastasis stage and lymph node metastasis. Further analysis using the Cox regression model revealed that Z38 expression was an independent prognostic factor of overall survival in patients with breast cancer (hazard ratio=4.74, 95% confidence interval 2.41-9.32). The nomogram presents a good prediction of the probability of overall survival of breast cancer patients (c-index: 0.792), and its predictive efficiency was further confirmed by the calibration curve. CONCLUSION: Our data highlighted the potential of lncRNA Z38 as novel candidate biomarker to identify patients with breast cancer at high risk of tumor death.