Association between p53 codon 72 polymorphisms and clinical outcome of nasopharyngeal carcinoma

We conducted a cohort study to investigate whether polymorphisms in p53 at codon 72 are associated with tumor response and survival time of advanced nasopharyngeal carcinoma (NPC) patients treated with radiotherapy. The study population included 127 subjects with NPC who were enrolled at Binzhou Medical University between September 2008 and December 2009. Cox proportional hazard regression was used to assess the association between polymorphisms in the p53 gene and progression-free survival (PFS) and overall survival (OS) of NPC patients. During the follow-up period, 42 patients died and 72 patients showed progression at the end of the study. Of the 127 patients, median PFS was 22.5 ± 1.2 months (1-36 months), and the median OS time was 28.2 ± 1.1 months (2-36 months). The p53 codon 72 Pro/Pro genotype was associated with a longer median PFS time of 30.3 months compared with 18.2 months for patients with Arg/Arg variants. Moreover, the p53 codon 72 Pro/ Pro genotype was associated with a longer median OS time of 31.6 months compared with 25.8 months for those with Arg/Arg variants; the P value was marginally significant. We showed that variants in p53 codon 72 may be an independent predictor for PFS and OS of NPC patients.