Table 1.
Summary of eligible studies considered in the meta-analysis
| First author(year) | Case no. | Control no. | Ethnicity | Country | Cancer type | Matched variables | Type of study |
|---|---|---|---|---|---|---|---|
| Cozar (2007) | 125 | 176 | Caucasian | Spain | Renal Cell Cancer | Age, sex, and residence area matched | Hospital-based |
| Cozar (2007) | 96 | 176 | Spanish | Spain | Colon Carcinoma | Ethnically matched | Hostipal-based |
| Su (2007) | 139 | 375 | Taiwanese Women | China | Cervical Squamous Cell Carcinoma | Age and sex matched | Hostipal-based |
| Pavkovic (2003) | 30 | 100 | Caucasians | Macedonia | CLL (+)AIHA | Age, sex, and residence area matched | Hospital-based |
| Pavkovic (2003) | 100 | 100 | Caucasians | Macedonia | CLL (-)AIHA | Age, sex, and residence area matched | Hospital-based |
| Suwalska (2008) | 170 | 224 | Polish | Poland | B-CLL | Age and sex matched | Hospital-based |
| Wang (2007) | 117 | 148 | Han people | China | Breast Cancer | Age matched | Hospital-based |
| Bouwhuis (2009) | 762 | 734 | German | Germany | Malignant Melanoma | Age matched | Hostipal-based |
| Sun (2008) | 1163 | 1132 | Han people | China | Lung Cancer (Beijing) | Aex matched | Hospital-based |
| Sun (2008) | 1032 | 1021 | Han people | china | Lung Cancer(Jiangsu) | Age-sex and residential area matched | Hospital-based |
| Sun (2008) | 1060 | 1070 | Han people | China | Breast Cancer (Beijing) | Age-sex and residential area matched | Hospital-based |
| Sun (2008) | 1037 | 1070 | Han people | China | Breast Cancer (Jiangsu) | Age-sex and residential area matched | Hospital-based |
| Sun (2008) | 1010 | 1008 | Han people | China | Esophagus Cancer (Beijing) | Age-sex and residential area matched | Hospital-based |
| Sun (2008) | 530 | 530 | Han people | China | Gastric Cardia Cancer (Beijing) | Age-sex and residential area matched | Hospital-based |
| Hou (2010) | 205 | 262 | Han people | China | Gastric Cancer | ||
| Dilmec (2008) | 56 | 162 | Trukese | Turkey | Colorectal Cancer | Age, sex and ethnically matched | Hostipal-based |
| Welsh (2009) | 897 | 819 | New Hampshire people | American | Non-melanoma Skin Cancer BCC | Age and sex matched | Hospital-based |
| Welsh (2009) | 684 | 819 | New Hampshire People | American | Non-melanoma Skin Cancer SCC | Age, sex, and residence area matched | Hospital-based |
| Hadinia (2007) | 105 | 190 | Irani | Iran | Colorectal Cancer | Hostipal-based | |
| Hadinia (2007) | 43 | 190 | Irani | Iran | Gastric Cancer | Age and sex matched | Hostipal-based |
| Wong (2006) | 118 | 147 | Taiwan People | China | Oral Squamous Cell Carcinoma | Age and sex matched | Hostipal-based |
| Piras (2005) | 100 | 128 | Sardinia People | Sardinia | Non-Hodgkin's Lymphoma | Sex matched | |
| Ghaderi (2004) | 197 | 151 | Iranian Women | Iran | Breast Cancer | Age matched | Hostipal-based |
| Qi (2010) | 124 | 407 | Chinese | China | Colorectal Cancer | Age and sex matched | |
| Cheng (2006) | 62 | 250 | Han Chinese | China | MALT Lymphoma | Age and sex matched | |
| Solerio (2005) | 186 | 238 | Caucasian | Italian | Colorectal Adenomas | Age, sex, and residence area matched | Hospital-based |
| Solerio (2005) | 132 | 238 | Caucasian | Italian | Colorectal Cancers | Age and sex matched | |
| Monne (2004) | 44 | 76 | Caucasian | Italy | Non-Hodgkin's Lymphomas(NHL) | Age and sex matched | Hospital-based |
| Chuang (2005) | 79 | 173 | White Germans | Germany | Myasthenia gravis MG(+)Thymoma | Hospital-based | |
| Chuang (2005) | 46 | 173 | White Germans | Germany | Myasthenia gravis MG(-)Thymoma | Hospital-based | |
| Xiao (2009) | 457 | 485 | Han Chinese | China | Nasopharyngeal Carcinoma | Age and sex matched | Hospital-based |
| Gu (2010) | 367 | 407 | Han Chinese | China | HBV-related HCC | Hospital-based |