Table 1.
Main characteristics of included studies.
| First author & Study year | Nationality | Age (yrs) | P16INK4a positive (n) | P16INK4a negative (n) | Detection method | Cut-off value | Follow-up time (yrs) | HR | 95% CI |
|---|---|---|---|---|---|---|---|---|---|
| Bethune 2012 | Canada | 63.0 mean | 23 | 20 | IHC | >0 | 3.9 mean | 0.53∧ | 0.26–1.06 |
| Gunia 2012 | Germany | 67.2 mean | 54 | 38 | IHC | >0 | 2.7 median | 0.44∧ | 0.23–0.84 |
| Ferrándiz 2013 | Spain | 69.0 median | 31 | 47 | IHC | H-score: 50 | 2.5 median | 0.13∗ | 0.02–0.98 |
| Bezerra 2015 | United States | 65.0 median | 23 | 30 | IHC | NM | NM | 0.54∧ | 0.13–2.19 |
| Zargar 2016 | United States | 60.0 median | 23 | 34 | IHC | Median | 1.8 median | 0.43∗ | 0.16–1.20 |
n, number; IHC, immunohistochemistry; yrs, years; NM, not mentioned; H-score, histological score; HR, hazard ratio; CI, confidence interval;
∧, HR outcome directly reported by studies; ∗, HR outcome extracted from survival curve.