MDM2 SNP 309 and p53p53 codon 72 polymorphisms are associated with the outcome of oral carcinoma patients receiving postoperative irradiation

Background and PurposeThe p53p53 tumor suppression pathway is important in effects associated with radiotherapy. The mouse double minute 2 (MDM2) plays a pivotal role in this pathway by down regulating p53p53. A functional T-to-G polymorphism at nucleotide 309 in MDM2   promoter intron 1 (SNP309) has been identified which influenced transcription activity. A G-to-C SNP at p53p53 codon 72 results in an Arg/Pro polymorphism, which is associated with apoptosis induction potential and p53p53 mutation status.Materials and methodsWe sequenced both MDM2   SNP309 and p53p53 codon 72 SNP in patients with oral squamous cell carcinoma (OSCC, n=189n=189), oral submucosal fibrosis (OSF, n=70n=70), and 116 controls.ResultsNeither MDM2   SNP309 nor p53p53 codon 72 SNP was associated with susceptibility to or the age at onset of OSCC or OSF. p53p53 codon 72 SNP Arg/Arg polymorphism was associated with the progression of OSCC, and the overall (OS) and disease-free survival (DFS) of irradiated patients. The MDM2 SNP309 G/G polymorphism was associated with poor OS in advanced OSCC, and the OS and DSF of irradiated patients. The combination of MDM2   SNP309 G/G and p53p53 codon 72 Arg/Arg polymorphism is associated with the worst OS and DFS.ConclusionsAdvanced OSCC has high mortality and recurrence. We identified that both MDM2   SNP309 and p53p53 codon 72 SNP could be useful factors for evaluating the outcome of advanced OSCC treated with adjuvant radiation.