Association of PIK3CA and MDM2 SNP309 with cervical squamous cell carcinoma in a Philippine population

Abstract

Background: PIK3CA and MDM2 SNP309 have been studied to be associated with cervical cancer. PIK3CA mutation is associated with poor treatment response and low survival rate while MDM2 is associated with tumorigenesis and poor prognosis in cervical cancer. Thus, we determined the prevalence of PIK3CA and MDM2 mutations in Filipino cervical cancer patients. Methods: Twenty-eight formalin-fixed paraffin-embedded cervical squamous cell carcinoma and 16 non-malignant cervix tissue biopsies of Filipino patients were subjected to PIK3CA gene and MDM2 SNP309 (rs2279744) analysis. Results: PIK3CA gene was found mutated in three (10.71 %) out of 28 cervical cancer patients included in this study. Among the HPV-negative cervical cancer patients, two (28.57 %) were positive for PIK3CA mutation and only one (4.76 %) tested positive among the HPV-positive cervical cancer patients. MDM2 SNP309 analysis revealed that T allele (71.43%) was more common in cervical cancer patients compared to the control group. TG genotype (p = 0.03; OR = 0.18, 95% CI 0.04-0.76) was associated with lower rates of cervical cancer when TT genotype was used as a reference point. Conclusion: PIK3CA gene mutation was present among Filipino cervical cancer patients and not in control patients. MDM2 SNP309 analysis revealed that TG genotype has lower association to cervical cancer when compared with the TT and GG genotypes.