Fig 1.
Flow diagram of cases included in the Taiwan retrospective cohort and study design.
1Results missing due to absent slide or tissue core, or major artifacts that prevented evaluation. 2Results missing due to absent DNA or invalid test. OPSCC, oropharyngeal squamous cell carcinoma; HPV, human papillomavirus; FFPE, formalin-fixed, paraffin-embedded; IHC, immunohistochemical staining; PCR-MA, multiplex PCR-MassArray.
Table 1.
HPV genotypes frequency.
Fig 2.
Yearly HPV occurrence among OPSCC cases by HPV DNA and/or p16 (A) or p16 alone (B).
The graphs show the correlation between the total frequency of HPV-positive (HPV+) and HPV-negative (HPV-) OPSCC cases, and the study years (see S3 Table). HPV status was assessed by (A) HPV DNA and p16 testing (N = 528) or (B) p16 scoring (N = 458). The association was evaluated in the Taiwan cohort from March 1998 to February 2016 by Spearman’s coefficient (ρ) and linear regression (R2). (A) HPV-: ρ = 0.6953, p = 0.0014; R2 = 0.5201, p = 0.0007. HPV+ ρ = 0.4093, p = 0.0917; R2 = 0.1952, p = 0.0664. (B) p16-: ρ = 0.6991, p = 0.0012; R2 = 0.5555, p = 0.0004. p16+ ρ = 0.4741, p = 0.0469; R2 = 0.2455, p = 0.0365.
Table 2.
Demographic and clinical characteristics.
Fig 3.
HPV-positive OPSCC is associated with increased survival time.
(A-B) Up to 5-year overall survival (OS) and disease-free survival (DFS) prognostic outcomes of the HPV variable in the whole OPSCC Taiwan cohort. HPV positivity is defined as HPV DNA-positive and/or p16-positive. (A) Table includes the multivariable hazard probabilities analyzed using Cox survival models and hazard ratio (HR) estimations, visualized by forest plots. The complete analysis is found in S6 Table, where estimates were reported for the full model with all covariates (HPV status, alcohol, smoking, betel quid, age, N- and T-stage) included as fixed effects. (B) Kaplan-Meier survival analysis. Plots represent the results for up to 5-year OS (left) and DFS (right) comparison between HPV-negative (HPV-) and HPV-positive (HPV+) groups. Log-rank analysis was used to compare the survival distributions (log-rank p-values are in the plots). HPV-, HPV-negative; HPV+, HPV-positive.
Fig 4.
Alcohol is associated with reduced OPSCC survival time.
(A-D) Prognostic outcomes of the alcohol, smoking, and betel quid variables within the whole cohort. We analyzed up to 5-year overall survival (OS) and disease-free survival (DFS) outcomes for high-risk habits. (A) Table includes the multivariable hazard probabilities analyzed using Cox survival models and hazard ratio (HR) estimations, visualized by forest plots, where estimates were reported for full model with all covariates (HPV status, alcohol, smoking, betel quid, age, N- and T-stage) included as fixed effects. The complete analysis is found in S6 Table. (B-D) Kaplan-Meier survival analysis. Plots represent the results for up to 5-year OS (left) and DFS (right) comparison between alcohol (B), smoke (C), and betel quid (D) groups. Log-rank analysis was used to compare the survival distributions (log-rank p-values are in the plots).
Fig 5.
In alcohol users, HPV is associated with improved OPSCC survival time.
(A-C) Prognostic outcomes of the alcohol, smoking, and betel quid variables within HPV risk groups. HPV positivity is defined as HPV DNA-positive and/or p16-positive. We analyzed up to 5-year overall survival (OS) and disease-free survival (DFS) outcomes. (A) Table includes the multivariable hazard probabilities analyzed using Cox survival models and hazard ratio (HR) estimations, adjusted for age, T- and N-stage, and visualized by forest plots. (B-C) Kaplan-Meier survival analysis. Plots represent the results for up to 5-year OS (B) and DFS (C) comparison between HPV groups stratified by alcohol groups. Log-rank analysis was used to compare the survival distributions (log-rank p-values are in the plots). The complete analysis is found in S7 Table and S3 Fig. HPV-, HPV-negative; HPV+, HPV-positive.