Table 1 Detailed characteristics of the 23 studies included in the meta-analysis
Publication year | Author | Nationality | Total cases | Cancer type | Therapy | Follow-up (months) | PDCD4 expression (cases) | Protein location | Examine methods | Dichotomic criteria | Cut-off value | Study variables |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
2003 | Chen et al. [22] | Germany | 124 | Lung cancer | NA | 24 (2–66) | 21 | NA | IHC | Positive/negative | IHC score = 1 | N category, clinical stage, histological differentiation |
2007 | Mudduluru et al. [28] | Germany | 71 | Colorectal cancer | Surgery | 36 (1–72) | 13 | Nucleus and cytoplasm | IHC | Positive/negative | IHC score = 1 | OS, DSS |
2008 | Wang et al. [34] | China | 43 | Ovarian epithelial carcinoma | NA | 50 (NA) | 18 | Nucleus and cytoplasm | IHC | Strong, moderate, weak, negative | IHC score = 3 | Clinical stage, DSS, histological differentiation |
2009 | Gao et al. [33] | China | 84 | Glioma | Surgery | 36 (NA) | 16 | NA | IHC | Positive/negative | Positive (+) | Clinical stage, DSS |
Wei et al. [35] | China | 79 | Ovarian invasive ductal carcinoma | Surgery + chemotherapy | 49 (26–97) | 40 | Total | Western blotting | High/low | Median | DFS | |
2010 | Motoyama et al. [23] | Japan | 105 | Gastric cancer | NA | 30 (1.2–134.4) | 28 | NA | QPCR | High/low | T/N ratio = 1 | N category, M category, clinical stage, histological differentiation |
Reis et al. [29] | Canada | 50 | Oral cancer | NA | 108 (NA) | 25 | NA | qPCR | High/low | Median | OS, DFS | |
2011 | Lim et al. [19] | Korea | 108 | Colorectal cancer | NA | NA | 64 | NA | IHC | Strong, moderate, weak, negative | IHC score = 2 | T category, N category, M category, clinical stage, histological differentiation |
|  | Feng et al. [20] | China | 54 | Laryngeal cancer | NA | NA | 33 | Nucleus and cytoplasm | IHC | Positive/negative | IHC score = 4 | N category, clinical stage, histological differentiation |
Kakimoto et al. [50] | Japan | 19 | Gastric cancer | NA | NA | 6 | Nucleus or cytoplasm | IHC | Strong, moderate, weak, negative | IHC score = 3 | Histological differentiation | |
2012 | Ding et al. [14] | China | 63 | Gastro-intestinal stromal tumor | NA | NA | 21 | NA | IHC | High/low | IHC score = 4 | Tumor size |
Nagao et al. [15] | Japan | 65 | Pancreatic ductal adenocarcinoma | NA | NA | 24 | Nucleus or cytoplasm | IHC | Strong, moderate, weak, negative | 30% cancer cells with PDCD4 (+) | Tumor size, T category, N category, OS, histological differentiation | |
Cao et al. [16] | Korea | 205 | Gastric cancer | NA | NA | 136 | NA | IHC | Positive/negative | 5% cancer cells with PDCD4 (+) | Tumor size | |
Li et al. [17] | China | 66 | Renal cell carcinoma | Surgery | 47.3 (18–65) | 31 | Nucleus & cytoplasm | IHC | High/low | IHC score = 2 | Tumor size, T category, M category, OS, histological differentiation | |
Wang et al. [21] | China | 60 | Laryngeal cancer | NA | NA | 26 | NA | IHC | Positive/negative | 30% cancer cells with PDCD4 (+) | N category, clinical stage, histological differentiation | |
|  | Meric-Bernstam et al. [30] | USA | 188 | Breast cancer | Surgery + endocrine therapy | 87 (1–197) | 78 | NA | IHC | Positive/negative | 5% cancer cells with PDCD4 (+) | Tumor size |
Horiuchi et al. [31] | Japan | 118 | Colorectal cancer | NA | 45 (2–89) | 61 | NA | qPCR | High/low | T/N ratio = 1 | OS, DFS | |
2013 | Guo et al. [7] | China | 122 | Gastric cancer | NA | 42 (3–84) | 36 | NA | IHC | Positive/negative | 6% cancer cells with PDCD4 (+) | Tumor size, N category, OS |
Zhen et al. [18] | China | 190 | Naso-pharyngeal cancer | NA | NA (4–126) | 73 | Cytoplasm | IHC | High/low | IHC score = 5 | T category, N category, M category, clinical stage, OS | |
Qi et al. [24] | China | 96 | Salivary adenoid cystic carcinoma | Surgery | 42 (3–68) | 34 | Nucleus and cytoplasm | IHC | High/low | IHC score = 4 | Clinical stage, OS, DSS | |
Ma et al. [26] | China | 195 | Digestive system cancer | NA | NA | 93 | Cytoplasm | IHC | Positive/negative | 30% cancer cells with PDCD4 (+) | Clinical stage, histological differentiation | |
2014 | Yu et al. [27] | China | 30 | Gastric cancer | NA | NA | 11 | NA | IHC | High/low | Stain index score = 6 | Histological differentiation |
Dou et al. [32] | China | 92 | Advanced rectal cancer | Surgery + nCRT | 60 (NA) | 40 | Nucleus and cytoplasm | IHC | High/low | 30% cancer cells with PDCD4 (+) | OS, DFS |