Table 1. Characteristics of the studies included in the meta-analysis.
| First author | Year | Country | Ethnicity | Cancer type | Total No. of patients | Median age (years) |
|---|---|---|---|---|---|---|
| Masao | 2009 | Japan | Asian | PC | 60 | 64.6 |
| Karsten | 2009 | Norway | Germanic | Prostate cancer | 104 | 62.0 |
| Chen | 2010 | China | Asian | Lung cancer | 52 | 58.2 |
| Shinichiro | 2010 | Japan | Asian | Lung cancer | 171 | 64 |
| Sadhna | 2011 | USA | Caucasian | GA | 159 | 63 |
| Mascolo | 2012 | Italy | Germanic | Oral cancer | 66 | 60.5 |
| Chen | 2014 | China | Asian | Lung cancer | 71 | 57.6 |
PC, pancreatic cancer; GA, gastric adenocarcinoma.