Table 6 Distribution of p53 codon 72 genotypes in human papilloma virus (HPV) positive and negative head and neck squamous cell carcinoma samples.

p53 codon 72 status	HPV+	HPV−	OR (95% CI)
P/P tumour tissue	6	9	Referent
R/P tumour tissue	23	8	4.3 (1.2 to 15.6)*
R/R tumour tissue	30	10	4.5 (1.3 to 15.4)†

P, Pro; R, Arg.

*p = 0.048, †p =  0.02, P_trend = 0.033.