A case‐control study on the SNP309T → G and 40‐bp Del1518 of the MDM2 gene and a systematic review for MDM2 polymorphisms in the patients with breast cancer

OBJECTIVE: The current research was conducted to study the association between the SNP309 and del1518 polymorphisms with the breast cancer in the patients with the Kurdish ethnic background from western Iran. Also, a systematic review of the relevant case‐control studies on the MDM2 polymorphisms in the patients with breast cancer was performed. METHODOLOGY: Two mL of peripheral blood was taken from 100 patients with breast cancer and 100 healthy individuals. The frequencies of MDM2 SNP309 and del1518 genotypes and alleles were determined using the PCR‐RFLP and PCR methods, respectively. RESULTS: The frequency of the TT, TG, and GG of MDM2‐SNP309 genotypes in the patients was obtained as 23%, 52%, and 25%, and they were equal to 22%, 40%, and 38% in the control group, respectively. Also, considering the MDM2‐del1518 polymorphism, the frequencies of ins/ins, ins/del, and del/del genotypes were equal to 52%, 41%, and 7% in the breast cancer group and they were equal to 62, 30, and 8% in the control group, respectively. Analysis of the results indicated that the GG genotype plays a protective role for the breast cancer in the recessive model (GG vs TT + TG) of SNP309 (χ(2) = 3.916, P = .048, and OR = 0.54). CONCLUSION: Our findings revealed that the GG genotype of MDM2‐SNP309 can play a protective role in the breast cancer disease. Also, our systematic review indicated that the SNP309, SNP285, and del1518 of MDM2 gene in different populations mostly did not have a significant association with the risk of breast cancer.