Table 1.
Characteristics of published studies included in this meta-analysis
| Authors | Year | Ethnicity | Tumor type | Definition of cases | Characteristics of controls (matched for) | Methods | Sample size |
|---|---|---|---|---|---|---|---|
| Bao [11] | 2011 | Asian | Colorectal cancer | Histologically confirmed | Healthy (age, gender, and residence) | PCR–RFLP | 544/533 |
| Fan [12] | 2008 | Asian | Colorectal cancer | Histologically confirmed | Healthy (age, gender, residence and ethnicity) | PCR–RFLP | 137/308 |
| Joes [13] | 2006 | Mixed | Colorectal cancer | Not described | Unclear (age, gender and ethnicity) | PCR–SSCP | 74/72 |
| Karpinski [14] | 2010 | Occident | Colorectal cancer | Not described | Healthy (age, gender, residence and ethnicity) | PCR–RFLP | 186/140 |
| de Vogel [15] | 2009 | Occident | Colorectal cancer | Histologically confirmed | Healthy (age, gender) | PCR–RFLP | 703/1,810 |
| Iacopetta [16] | 2009 | Occident | Colorectal cancer | Histologically confirmed | Healthy (age, gender, and residence) | PCR–RFLP | 828/949 |
| Reeves [17] | 2008 | Occident | Colorectal cancer | Not described | Healthy (age, gender, and ethnicity) | PCR–RFLP | 194/210 |
| Aung [18] | 2005 | Asian | Gastric cancer | Histologically confirmed | Healthy (age, gender) | PCR–RFLP | 152/247 |
| Hu [19] | 2010 | Asian | Gastric cancer | Histologically confirmed | Healthy (age, gender, and residence) | PCR–RFLP | 259/262 |
| Wang [20] | 2005 | Asian | Gastric cancer | Histologically confirmed | Healthy (age, gender, and residence) | PCR–RFLP | 212/294 |
| Succi [21] | 2013 | Occident | HNSCC | Histologically confirmed | Healthy (gender) | PCR–RFLP | 237/488 |
| Liu [22] | 2008 | Occident | HNSCC | Histologically confirmed | Healthy (age, gender) | PCR–RFLP | 832/843 |
| Ezzikouri [23] | 2009 | African | Hepatocellular carcinoma | Not described | Unclear (age, gender and ethnicity) | PCR–RFLP | 96/222 |
| Wu [24] | 2007 | Asian | Hepatocellular carcinoma | Histologically confirmed | Healthy (age, gender and ethnicity) | PCR–RFLP | 100/140 |
| Lao [25] | 2013 | Asian | Hepatocellular carcinoma | Not described | Healthy (age, gender) | PCR–RFLP | 108/216 |
| Eftekhar [26] | 2014 | Asian | Breast cancer | Histologically confirmed | Healthy (age) | PCR–RFLP | 100/138 |
| Montgomery [27] | 2004 | Occident | Breast cancer | Not described | Unclear (age) | PCR–RFLP | 352/258 |
| Li [28] | 2005 | Asian | Acute leukemia | Not described | Healthy | PCR–RFLP | 160/240 |
| Shen [10] | 2002 | Occident | Lung cancer | Histologically confirmed | Unclear (age, gender, residence and ethnicity) | PCR–RFLP | 319/340 |
| Singal [29] | 2005 | Occident | Prostate cancer | Not described | BPH | PCR–RFLP | 81/42 |
| Hernández-Sotelo [30] | 2013 | Occident | Cervical cancer | Histologically confirmed | Healthy (age) | PCR–RFLP | 70/200 |
| Mostowska [31] | 2013 | Occident | Ovarian cancer | Histologically confirmed | Healthy (age) | PCR–RFLP | 159/180 |
PCR Polymerase chain reaction, RFLP restriction fragment length polymorphism, HNSCC head and neck squamous cell carcinoma, BPH benign prostatic hypertrophy