Predictive polymorphisms for breast cancer in postmenopausal Mexican women
Mónica Sierra-Martínez1, Leticia Hernández-Cadena2, José Rubén García-Sánchez3, Gustavo Acosta Altamirano4, Carmen Palacios-Reyes5, Patricia García Alonso-Themann6, Liliana García-Ortiz7, Laura Itzel Quintas-Granados8, Octavio Daniel Reyes-Hernández5
1 Laboratory of Genetics and Molecular Diagnostics, Juarez Hospital of Mexico; Postgraduate Studies and Research Section, School of Medicine, National Polytechnique Institute, Mexico City, Mexico
2 Department of Environmental Health, National Institute of Public Health, Research Center for Population Health, Mexico City, Mexico
3 Postgraduate Studies and Research Section, School of Medicine, National Polytechnique Institute, Mexico City, Mexico
4 Department of Finance, Institute for Social Security and Services for State Workers, Mexico City, Mexico
5 Laboratory of Genetics and Molecular Diagnostics, Juarez Hospital of Mexico, Mexico City, Mexico
6 Pediatric Monitoring, National Institute of Perinatology, Mexico City, Mexico
7 Division of Genomic Medicine, CMN "20 de Noviembre", Institute for Social Security and Services for State Workers, 7Genomic Sciences Postgraduate, Autonomous University of Mexico City, Mexico
8 Genomic Sciences Postgraduate, Autonomous University of Mexico City, Mexico
Octavio Daniel Reyes-Hernández,
5160 Avenue National Polytechnic Institute, Gustavo A. Madero, Magdalena de Las Salinas, ZP 07760 Mexico City. Laboratory of Genetics and Molecular Diagnostics at Juarez Hospital of Mexico
Source of Support: None, Conflict of Interest: None
Context: Several factors contribute to the increase in breast cancer (BC) incidence, such as lifetime exposure to estrogen, early menarche and older ages at first birth, menopause, and the increased prevalence of postmenopausal obesity. In fact, there is an association between an increased BC risk and elevated estrogen levels, which may be involved in carcinogenesis via the estrogen receptor alpha (ERa) encoded by the ESR1 gene. Interestingly, there is an antagonistic relationship between ERa and the aryl hydrocarbon receptor (AhR) in BC cells.
Aims: Herein, we explore the combined effects of the ESR1 (XbaI, PvuII) and AhR polymorphisms on BC development in Mexican women according to their menopausal status.
Settings and Design: Investigation was performed using a cases and controls design.
Subjects and Methods: In a group of 96 cases diagnosed with BC and 111 healthy women, the single-nucleotide polymorphisms ESR1 (XbaI, PvuII) and AhR gene were identified by qPCR.
Statistical Analysis Used: Chi-square test or Fisher's exact test were used. Statistical analyses were conducted using the STATA statistical package (Version 10.1, STATA Corp., College Station, TX, USA).
Results: The G/G XbaI genotype was more prevalent in the cases than in the controls (P = 0.008). Moreover, Mexican women carrying the XbaI (wild type [WT]/G or G/G) ESR1 genotype have higher risk (12.26-fold) for developing postmenopausal BC than individuals carrying the WT/WT genotype.
Conclusions: The presence of the G/G genotype of XbaI may be considered a susceptibility allele in Mexican women. Due to increased postmenopausal BC risk, the XbaI (WT/G or G/G) alleles may be used as a postmenopausal predictive factor for BC in Mexican women.