@article {LIN3863, author = {WEI-YU LIN and YU-CHING CHOU and MEI-HSUAN WU and HAN-BIN HUANG and YI-LIN JENG and CHO-CHIEH WU and CHENG-PUNG YU and JYH-CHERNG YU and SAN-LIN YOU and TANG-YUAN CHU and CHIEN-JEN CHEN and CHIEN-AN SUN}, title = {The MTHFR C677T Polymorphism, Estrogen Exposure and Breast Cancer Risk: A Nested Case-control Study in Taiwan}, volume = {24}, number = {6}, pages = {3863--3868}, year = {2004}, publisher = {International Institute of Anticancer Research}, abstract = {Background: We evaluated the effects of the MTHFR C677T polymorphism and its interaction with estrogen exposure on breast cancer risk in a nested case-control study conducted in Taiwan. Materials and Methods: A total of 88 histologically confirmed breast cancer cases and 344 cancer-free controls were recruited between July 1992 and December 2000. The MTHFR C677T genotype was determined by a PCR-RFLP-based assay. All subjects completed in-person interviews. Results: There was a significant trend of breast cancer in relation to prolonged exposure to estrogens prior to the first full-term pregnancy (FFTP)(p for trend=0.0015). In contrast, there was no statistically significant association between the risk of breast cancer and the MTHFR C677T genotype. However, a significantly elevated risk of breast cancer predisposed by the MTHFR 677T variant genotype (CT and TT) was observed in women with prolonged exposure to estrogens prior to FFTP (adjusted OR=4.98, 95\% CI=2.00-12.43).Conclusion: The results of this study suggest that the MTHFR 677T variant genotype per se may have no overall association with breast cancer risk, but a sizable association could be observed in the presence of relevant environmental exposure. Copyright{\textcopyright} 2004 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved}, issn = {0250-7005}, URL = {https://ar.iiarjournals.org/content/24/6/3863}, eprint = {https://ar.iiarjournals.org/content/24/6/3863.full.pdf}, journal = {Anticancer Research} }