The prognostic value of homeobox A9 (HOXA9) methylation in solid tumors: a systematic review and meta-analysis

Background: The prognosis of homeobox A9 (HOXA9) methylation have been assessed in a variety of cancers; nevertheless, the results remain undetermined due to discrete outcome and the limitations of small sample size. Therefore, we conducted a meta-analysis to explore the effect of HOXA9 methylation on the prognostic outcomes of patients with solid tumors. Methods: Qualified studies were verified by searching PubMed, Excerpta Medica Database and Web of Science until September, 2020. Clinicopathological factors and hazard ratio (HR) of 95% confidence interval (95% CI) were selected. Subgroup analysis including carcinoma category, analysis method and sample size were adopted. Results: In the meta-analysis 1,031 patients with solid carcinoma from 7 eligible investigations were involved. Among human cancer we discovered that the high HOXA9 methylation level was negative correlative with overall survival (OS) (HR =2.36; 95% CI: 1.70-3.26). In the subgroup analysis, we found HOXA9 methylation over-expression had statistical significance with poorer OS in lung cancer patients (HR =3.08, 95% CI: 1.70-5.55, P=0.002) and non-lung cancer (HR =2.10, 95% CI: 1.42-3.10, P=0.0002). Similar result was found in sample size. Greater than or equal to 100 (HR =2.31, 95% CI: 1.54-3.45, P<0.0001) and less than 100 (HR =2.45, 95% CI: 1.42-4.23, P=0.001). Discussion: HOXA9 methylation has a significantly estimable biomarker of predicting poor prognosis and a potential target for therapy in solid malignant carcinoma from our meta-analysis.