Clinicopathological association and prognostic value of long non-coding RNA CASC9 in patients with cancer: A meta-analysis

Several studies have reported a prognostic role of the long non-coding RNA (lncRNA) cancer susceptibility candidate 9 (CASC9) in various cancer types, but its clinical significance has remained inconclusive. The aim of the present meta-analysis was to evaluate the impact of CASC9 expression on the prognosis and clinicopathological features of patients with cancer patients. The PubMed, Embase, Cochrane Library and Web of Science databases were searched for relevant literature and eight studies, including 565 patients with cancer, were selected. The quality of these studies was appraised with the Newcastle-Ottawa Scale (NOS) and the association between CASC9 expression and prognosis or clinicopathological features was analyzed. Patients with high expression levels of CASC9 in their tumor tissues had a lower overall survival rate compared with those in the low CASC9 expression group (hazard ratio=2.25, 95% CI: 1.60-3.17, P<0.001). Furthermore, elevated CASC9 expression was significantly associated with deeper tumor invasion [odds ratio (OR)=2.66, 95% CI: 1.72-4.14, P<0.001], poor tumor differentiation (OR=2.44, 95% CI: 1.24-4.78, P=0.009), lymph node metastasis (OR=3.42, 95% CI: 1.98-5.92, P<0.001) and advanced clinical stage (OR=3.21, 95% CI: 2.21-4.66, P<0.001). In conclusion, CASC9 is a promising biomarker for predicting the prognosis of cancer patients and should be validated in the clinic.