Fig. 4

Kaplan Meier estimates of overall survival stratified according to history of alcohol consumption in combination with HPV status. Patients with HPV-associated OPSCC were found to have better overall survival rates compared to HPV-independent OPSCC patients (Log-rank test, pooled over strata; p < 0.001; n = 131). Pairwise statistical comparisons between patients with HPV-associated OPSCC who had no history of alcohol consumption and those that did, showed no statistically significant difference (Log-rank test, pairwise over strata; p = 0.612; n = 131). Similarly, pairwise statistical comparisons between patients with HPV-independent OPSCC who had no history of alcohol consumption and those that did, showed no statistically significant difference (Log-rank test, pairwise over strata; p = 0.222; n = 131)