The association of HMGB1 expression with clinicopathological significance and prognosis in Asian patients with colorectal carcinoma: a meta-analysis and literature review

BACKGROUND: The association of high mobility group box 1 (HMGB1) expression with clinicopathological significance and prognosis in Asian patients with colorectal carcinoma (CRC) remains controversial. The purpose of this study was to conduct a meta-analysis and literature review to identify the role of HMGB1 in the development and prognosis of CRC in Asians. METHODS: All eligible studies regarding the association between HMGB1 expression in tissue with clinicopathological significance and prognosis in Asian patients with CRC published up to January 2015 were identified by searching PubMed, Web of Science, Chinese National Knowledge Infrastructure, and WanFang database. Analysis of pooled data was performed, while odds ratio (OR) or hazard radio with 95% confidence interval (CI) was calculated and summarized to evaluate the strength of this association in fixed- or random-effects model. RESULTS: The expression level of HMGB1 in CRC tissues was much higher than normal colorectal tissues (OR =27.35, 95% CI 9.32–80.26, P<0.0001) and para-tumor colorectal tissues (OR =10.06, 95% CI 4.61–21.95, P<0.0001). There was no relation between the HMGB1 expression and sex, age, clinical T stage, tumor size, and location (colon or rectum cancer). However, a significant relation was detected between the HMGB1 expression and clinical stage (American Joint Committee on Cancer 7), lymph node metastasis, distant metastasis, tumor invasion depth, and differentiation rate (P=0.002, P≤0.0001, P<0.0001, P<0.0001, and P=0.007, respectively). Patients with higher HMGB1 expression had shorter overall survival time, whereas patients with lower level of HMGB1 had better survival (hazard ratio =1.40, 95% CI 0.98–1.82, P<0.0001). CONCLUSION: In this meta-analysis, our results illustrated the significant relationship of HMGB1 protein overexpression in tissues with clinicopathological characteristics and prognosis of CRC. Thus, HMGB1 may be a promising marker in predicting the clinical outcome of patients with CRC. However, more well-designed studies of large sample size are warranted to validate the findings of current study.