Table 1. Characteristics of the studies included in the meta-analysis.
| First author | Year | Country | Ethnicity | Cancer type | Total number of patients | Median age (years) |
|---|---|---|---|---|---|---|
| Zhang | 2010 | China | Asian | LA | 112 | 57 |
| Ge | 2010 | China | Asian | HSCC | 85 | 60 |
| Chen | 2012 | China | Asian | Lung cancer | 113 | 57.2 |
| Dong | 2012 | China | Asian | Hepatocellular cancer | 152 | NR |
| He | 2012 | China | Asian | ESCC | 153 | 56.4 |
| Lilly | 2012 | America | Caucasian | HNSCC | 110 | NR |
| Li | 2012 | China | Asian | ESCC | 50 | 62 |
| Zhang | 2013 | China | Asian | Ovarian cancer | 74 | NR |
| Li | 2013 | China | Asian | Lung cancer | 102 | NR |
| Ji | 2014 | China | Asian | CSCC | 43 | 49.6 |
| Takako | 2014 | Japan | Asian | Breast cancer | 93 | NR |
Abbreviations: CSCC, cervical squamous cell cancer; ESCC, esophageal squamous cell carcinoma; HSCC, hypopharyngeal squamous cell carcinoma; HNSCC, head and neck squamous cell carcinoma; LA, lung adenocarcinoma; NR, not reported.