Homeobox protein CDX2 as a prognostic biomarker in solid malignancies: a meta-analysis.

Background: CDX2 is a caudal-homeobox gene and its expression is abnormal in numerous tumour cell types. Nevertheless, its prognostic value for solid tumours requires further investigation. Hence, we conducted a meta-analysis to determine the significance of CDX2 as a prognostic biomarker in solid malignancies systematically.

Materials and Methods: We performed a systematic literature search in PUBMED and EMBASE up to May 2017. Retrospective studies comparing the prognostic value of different CDX2 levels in human malignancies were included. Data extractions and methodological assessments were performed separately by two investigators using a standard procedure. The statistical procedures were performed using Review Manager 5.3 and STATA/MP 14.0.

Results: A total of 26 retrospective studies met the inclusion criteria and comprised 5008 participants. Patients with CDX2 overexpression had significantly better 3-year, 5-year, 10-year and disease-free survival outcomes in solid malignancies, regardless of the cancer type, mean age, and source region. Nevertheless, there was no significant difference in the patients from Europe. The expression level of CDX2 was not statistically associated with cancer relapse. Moreover, our analysis showed that CDX2 overexpression is correlated to better responses to chemotherapy in patients with TNM IV stage cancers. The stability of the pooled outcomes was verified by sensitivity analysis. The funnel plots, Egger's test and Begg's test jointly confirmed that there was no publication bias.

Conclusions: Overexpression of CDX2 is a reliable biomarker of a better prognosis in solid malignancies.