Table 1.
Characteristics of all included studies
| Study, year [ref] | Country | Age (year) (range or mean ± SD) | Study type |
Lung cancer cases |
Controls |
Method of copper measurement | |||
|---|---|---|---|---|---|---|---|---|---|
| n | Female (%) | Copper: mean ± SD | n | Copper: mean ± SD | |||||
| Sun et al. 1991 [8] | China | 30–75 | Case-control | 91 | 0.00 | 1.267 ± 0.278 (µg/mL) | 138 | 0.921 ± 0.198 (µg/mL) | AAS (IL-951, USA) |
| Sun et al. 1991 [8] | China | 30–75 | Case-control | 13 | 100.00 | 1.468 ± 0.416 (µg/mL) | 114 | 1.111 ± 0.324 (µg/mL) | AAS (IL-951, USA) |
| Cobanoglu et al. 2010 [13] | Turkey | 54 ± 8.29 | Case-control | 30 | 33.33 | 0.977 ± 0.316 (µg/dL) | 20 | 1.748 ± 0.198 (µg/dL) | UNICAM-929 spectrophotometer (Unicam Ltd., Cambridge, UK) |
| Diez et al. 1989 [19] | Spain | 60 ± 7 | Case-control | 64 | 7.81 | 1.4 ± 0.316 (µg/mL) | 100 | 1 ± 0.182 (µg/mL) | AAS (Perkin-Elmer 5.000) |
| Huhti et al. 1980 [20] | Finland | 37–80 | Case-control | 149 | 5.37 | 1.42 ± 0.3 (mg/L) | 19 | 1.03 ± 0.26 (mg/L) | AAS (Perkin-Elmer Model 303) |
| Jin et al. 2011 [9] | China | 34.9 ± 21.3 | Case-control | 154 | 10.39 | 1.624 ± 0.818 (µg/mL) | 154 | 1.285 ± 0.524 (µg/mL) | AAS (Wako Pure Chemical Industries, Osaka, Japan) |
| Oyama et al. 1994 [21] | Japan | 26–83 | Case-control | 109 | 34.86 | 122.9 ± 3.77 (µg/dL) | 53 | 109.5 ± 5.39 (µg/dL) | AAS (Wako Pure Chemical Industries, Osaka, Japan) |
| Zowczak et al. 2001 [22] | Poland | 42–87 | Case-control | 14 | 14.29 | 22.9 ± 6.2 (µmol/L) | 18 | 15 ± 1.5 (µmol/L) | Flame AAS (Perkin Elmer) |
| Feng et al. 2006 [23] | China | 18–82 | Observation trials | 13 | NA | 19 ± 2.36 (µmol/L) | 36 | 14.92 ± 2.71 (µmol/L) | Flame AAS |
| Zhang et al. 1997 [24] | China | 25–80 | Case-control | 64 | 40.63 | 1.512 ± 0.374 (mg/L) | 31 | 1.061 ± 0.157 (mg/L) | AAS |
| Jin et al. 2001 [25] | China | 45–70 | Case-control | 40 | 7.50 | 21.7 ± 6.55 (µmol/L) | 46 | 17.2 ± 2.48 (µmol/L) | AAS |
| Zhang et al. 1994 [26] | China | 59 ± 9 | Case-control | 40 | 10.00 | 29.67 ± 5.34 (µmol/L) | 24 | 18.84 ± 2.98 (µmol/L) | AAS |
| Xu et al. 1993 [11] | China | 56 ± 7.5 | Case-control | 42 | 9.52 | 19.14 ± 4.29 (µmol/L) | 40 | 19.61 ± 1.88 (µmol/L) | AAS |
| Zhou et al. 1995 [27] | China | 39–69 | Case-control | 186 | 31.18 | 1.481 ± 0.163 (µg/mL) | 150 | 1.035 ± 0.094 (µg/mL) | AAS |
| Chen et al. 1994 [28] | China | 37–72 | Case-control | 58 | 25.86 | 20.1 ± 5.6 (mol/L) | 100 | 18.5 ± 5.1 (mol/L) | AAS (MFX-ID) |
| Luo et al. 1996 [29] | China | 40–70 | Case-control | 35 | NA | 17.94 ± 4.09 (µmol/L) | 22 | 9.76 ± 1.89 (µmol/L) | AAS |
| Mo et al. 1995 [30] | China | 58.5 | Case-control | 57 | 21.05 | 153.44 ± 33.38 (µg/dL) | 46 | 93.77 ± 12.86 (µg/dL) | AAS |
| He et al. 1995 [31] | China | 34–72 | Case-control | 143 | 39.16 | 24.194 ± 9.135 (µmol/L) | 50 | 17.402 ± 5.264 (µmol/L) | AAS |
| Wei et al. 2002 [32] | China | 22–76 | Case-control | 79 | 41.77 | 1.093 ± 0.073 (µg/mL) | 32 | 0.867 ± 0.039 (µg/mL) | AAS ( p-100, PE Co., USA) |
| Huang et al. 1999 [33] | China | 40–72 | Case-control | 27 | 14.81 | 1.341 ± 0.304 (µg/mL) | 45 | 1.084 ± 0.182 (µg/mL) | AAS |
| Zhao et al. 1993 [34] | China | 43–62 | Case-control | 46 | 13.04 | 21.36 ± 4.6 (µmol/L) | 50 | 15.76 ± 4.2 (µmol/L) | AAS (BJKP-36, Beijing, China) |
| He et al. 2011 [10] | China | 38–69 | Case-control | 104 | 29.81 | 23.15 ± 3.16 (µmol/L) | 122 | 14.52 ± 1.75 (µmol/L) | AAS |
| Chen et al. 1998 [35] | China | 47–72 | Case-control | 43 | 32.56 | 19.08 ± 3.41 (µmol/L) | 180 | 13.85 ± 2.36 (µmol/L) | AAS (A670, Shimadzu, Japan) |
| Liang et al. 1992 [36] | China | 61 | Case-control | 57 | 21.05 | 28.75 ± 9.7 (µmol/L) | 80 | 19.76 ± 3.56 (µmol/L) | AAS (WFX-ID, China) |
| Huang et al. 1998 [12] | China | 25–65 | Case-control | 136 | 19.12 | 21.453 ± 5.783 (µmol/L) | 7101 | 20.713 ± 5.508 (µmol/L) | AAS (AA670/C2H2, Shimadzu) |
| Wang et al. 2003 [37] | China | 28–69 | Case-control | 50 | 40.00 | 1.04 ± 0.2 (µg/L) | 60 | 0.77 ± 0.22 (µg/L) | AAS |
| Cheng et al. 2011 [38] | China | 37–68 | Case-control | 197 | 32.99 | 1.19 ± 0.13 (µmol/L) | 93 | 0.87 ± 0.35 (µmol/L) | AAS |
| Xie et al. 2000 [39] | China | 35–68 | Case-control | 64 | 45.31 | 25.3 ± 6.3 (µmol/L) | 100 | 22.1 ± 1.7 (µmol/L) | AAS |
| Du et al. 1996 [40] | China | 22–73 | Case-control | 73 | 31.51 | 21.3 ± 4.3 (µmol/L) | 63 | 15.3 ± 3.4 (µmol/L) | AAS |
| Zhu et al. 1997 [41] | China | NA | Case-control | 56 | NA | 21.05 ± 3.56 (µmol/L) | 118 | 16.01 ± 2.13 (µmol/L) | AAS (3030, Perkin Elmer Zeeman, USA) |
| Zhang et al. 2000 [42] | China | 25–77 | Case-control | 310 | 17.74 | 1.151 ± 0.264 (µg/mL) | 48 | 1.068 ± 0.233 (µg/mL) | AAS (180-80, Shimadzu, Japan) |
| Hu et al. 2000 [43] | China | 36–77 | Case-control | 56 | 17.86 | 1.508 ± 0.379 (µg/mL) | 60 | 1.403 ± 0.148 (µg/mL) | AAS |
| Guo et al. 1994 [44] | China | 55.1 | Case-control | 26 | 26.92 | 2.81 ± 1.54 (µg/mL) | 26 | 0.82 ± 0.21 (µg/mL) | AAS (AA-40p, Varian, USA) |
| Han et al. 1999 [45] | China | NA | Case-control | 400 | NA | 1.12 ± 0.43 (µg/mL) | 100 | 0.87 ± 0.26 (µg/mL) | AAS (3030, PE Co., USA) |
AAS, atomic absorption spectrophotometry; SD, standard deviation; NA, not available