Supplementary Material for: Cytomegalovirus Infection Is a Risk Factor in Gastrointestinal Cancer: A Cross-Sectional and Meta-Analysis Study

<b><i>Background:</i></b> This study was planned to investigate the association between<b><i></i></b>human cytomegalovirus (HCMV) infection and gastrointestinal cancer (GIC) risk, by undertaking a meta-analysis and case-control cross-sectional study. <b><i>Summary:</i></b> A cross-sectional study analysis of 160 GIC patients and 100 control subjects indicated significantly higher HCMV prevalence in GIC patients based on the HCMV IgM test. However, a similar analysis based on an IgG test revealed no significant relationship. Further meta-analysis of 11 studies, including 1,044 patients and 991 healthy subjects, displayed HCMV infection as an important risk factor for not only colorectal cancer occurrence and development based on a HCMV DNA test, but also for GIC based on a HCMV IgM test. However, the IgG test again displayed no significant relationship between HCMV infection and GIC occurrence. <b><i>Key Message:</i></b> Overall, our study revealed that HCMV infection is associated with an increased GIC risk. However, additional studies are warranted to elucidate the molecular mechanism underlying this association.