Figure 2

Adjusted Relative Risk (RR) of the 5-year overall survival (OS) compared to the HPV⁺/p16⁺ subgroup. Forest plot of RR among included studies for the 5-year OS of the HPV⁺/p16⁺ subgroup compared to (A) HPV⁻/p16⁻, (B) HPV⁻/p16⁺ and (C) HPV⁺/p16⁻. Combined RR was calculated by a random mode.