Tumor expression of CXCL12 and survival of patients with colorectal cancer: A meta-analysis

C-X-C motif chemokine ligand 12 (CXCL12) has been suggested as a possible biomarker of poor prognosis in patients with various malignancies. However, the association between tumor expression of CXCL12 and survival of patients with colorectal cancer (CRC) remains to be comprehensively analyzed. A meta-analysis to systematically evaluate this association was performed in the present study. Relevant cohort studies were retrieved by searching the PubMed, Embase and Web of Science databases from inception to March 22, 2022. A conservative random-effect model incorporating the possible influence of between-study heterogeneity was used to pool the results. A total of 14 cohort studies that included 2,060 patients with CRC contributed to the meta-analysis, and 1,055 (51.2%) of them had higher tumor expression levels of CXCL12. Pooled results showed that a higher tumor expression level of CXCL12 was associated with poor overall survival [hazard ratio (HR), 1.74; 95% confidence interval (CI), 1.29-2.34; P<0.001; I², 33%] and progression-free survival (HR, 2.00; 95% CI, 1.47-2.73; P<0.001; I², 33%). Subgroup analyses showed that the association between higher cancer expression levels of CXCL12 and poor survival in patients with CRC was not significantly affected by the country of the study, the location of the tumor, the cancer stage or the methods used for measuring tumor CXCL12 levels (all P>0.05). In conclusion, the study found that a higher tumor expression level of CXCL12 was associated with the poor survival of patients with CRC. Studies are warranted to determine if CXCL12-targeted intervention could improve the prognosis of patients with CRC.