Table 1. Main characteristics and results of the eligible studies.
| First author | Year | Patients source | SCC/ADC/others | Stage | No. of Pts | Method | Cutoff | HR estimation | HR (95% CI) |
|---|---|---|---|---|---|---|---|---|---|
| Aresti | 2014 | Spain | 42/41/13 | I–IV | 96 | RT-PCR/ELISA | NA | HR | 0.70 (0.38–1.29) |
| Monica | 2012 | Italy | 34/57/15 | III–IV | 106 | IHC | NA | HR | 1.75 (1.00–3.03) |
| Navaratnam | 2012 | Canada | NA | I–IV | 79 | IHC | >60 score | HR | 0.41 (0.21–0.80) |
| Verma | 2012 | Japan | 36/129/4 | I–IV | 169 | IHC | >10% | HR | 0.721 (0.30–0.98) |
| Karlsson | 2011 | Sweden | 0/68/0 | I–V | 68 | IHC | >30% | HR | 0.47 (0.22–1.01) |
| Mah | 2011 | American | 93/226/58 | I–IV | 377 | IHC | ≥3 score | HR | 1.6 (0.84–2.09) |
| Stabile | 2011 | American | 62/103/18 | I–IV | 183 | IHC | ≥7 score | HR | 1.05 (1.00–1.10) |
| Mauro | 2010 | Argentina | 18/33/6 | I | 58 | IHC | ≥10% | HR | 0.57 (0.13–0.80) |
| Skov | 2008 | Denmark | 56/40/8 | I–III | 104 | IHC | ≥10% | HR | 0.63 (0.41–0.97) |
| Schwartz | 2005 | American | 13/231/35 | NA | 278 | IHC | ≥10% | HR | 1.01 (0.65–1.57) |
| Kawai | 2005 | Japan | 28/102/2 | I–IV | 132 | IHC | ≥5 score | HR | 1.49 (0.76–2.93) |
SCC, squamous cell carcinoma; ADC, adenocarcinoma; No. of Pts, number of patients; CI, confidence interval; RT-PCR, reverse transcription-polymerase chain reaction; ELISA, enzyme linked immunosorbent assay; HR, hazard ratios; IHC, immunohistochemistry.