High expression of HOXB7 is an unfavorable prognostic factor for solid malignancies: A meta-analysis

BACKGROUND: HOXB7 is abnormally expressed in a variety of tumors, but its prognostic value remains unclear due to sample size limitation and outcome inconsistency in previous studies. This meta-analysis was performed to explore the effect of HOXB7 expression on prognoses and clinicopathological factors in range of the whole solid tumors. METHODS: PubMed, EMBASE, and Web of Science databases were searched to identify included studies. Hazard ratios (HR) with its 95% confidence interval (CI) and clinicopathological factors were extracted. Subgroup analyses were performed according to histopathological type, tumor occurrence systems, and HOXB7 detection methods. RESULTS: A total of 3430 solid tumors patients from 20 studies (21 cohorts) were included in the meta-analysis. The results showed that high HOXB7 expression was significantly associated with worse survival (overall survival: HR = 1.98, 95%CI: 1.74–2.26, P < .001 and disease-free survival: HR = 1.59, 95%CI: 1.21–2.09, P = .001), more advanced tumor-node-metastasis (TNM) stage (odds ratio [OR] = 2.14, 95%CI: 1.68–2.73, P < .001), positive lymph node metastasis (OR = 2.16, 95%CI: 1.74–2.70, P < .001), more distant metastasis (OR = 1.63, 95%CI: 1.01–2.63, P = .048), poorer differentiation (OR = 1.48, 95%CI: 1.14–1.91, P = .003), and higher Ki-67 expression (OR = 2.53, 95%CI: 1.68–3.84, P < .001). Subgroup analysis showed that survival of patients with HOXB7 high expression was worse in either squamous cell carcinomas or non-squamous cell carcinomas, digestive tumors or non-digestive tumors, and protein level or mRNA level. CONCLUSION: High HOXB7 expression might be a valuable biomarker of poor prognosis for solid tumors. HOXB7 promotes tumor proliferation and metastasis, and is associated with poorer differentiation, more advanced stage, even the chemotherapy resistance, suggesting that HOXB7 is a potential therapeutic target for solid tumors.