Association of MTHFR 677C>T polymorphism with breast cancer risk: A case–control study and meta‑analysis

Abstract

Background and Objectives: Breast cancer is a complex, multifactorial disease that arises as a result of interactions between multiple genes and environmental factors. Methylenetetrahydrofolate reductase (MTHFR) is a low susceptibility gene, involved in folate metabolism. It assists in conversion of 5,10‑methylenetetrahydrofolate to 5‑methyltetrahydrofolate which further leads to DNA methylation. 5,10‑methylenetetrahydrofolate assists in conversion of uracil to thymine and purine synthesis for DNA synthesis. MTHFR 677C>T polymorphism alters the activity of MTHFR enzyme potentially effecting DNA repair and synthesis, hence a potential risk for cancer like breast cancer. Hence, the present study was conducted to evaluate association of MTHFR 677C>T polymorphism and breast cancer in Punjabi population. Moreover, a meta‑analysis was conducted to address the same. Materials and Methods: A total of 247 breast cancer patients and 247 controls were selected from Punjabi population for analysis using PCR‑RFLP method. For meta‑analysis, 67 studies were selected, and allele contrast, homozygous, heterozygous, dominant, and recessive models were used to evaluate the association between MTHFR 677C>T and breast cancer. Results: The frequencies of CC, CT, and TT genotype were 68.4% versus 74.5%, 28.7% versus 23.5%, and 2.9% versus 2.0% in patients and controls, respectively. There was no significant difference found. In meta‑analysis, significant association was found in overall and Asian population while no significant association was found in Caucasians. Interpretation and Conclusions: MTHFR 677C>T polymorphism is not a risk factor for breast cancer in Punjabi population. Inconsistency with the meta‑analysis can be due to ethnic diversity.