title: Association of the Alu insertion polymorphism in the progesterone receptor gene with breast cancer in a Mexican population.
abstract: BACKGROUND
  The progesterone receptor (PR) gene plays an important role in reproduction-related events. Data on polymorphisms in the PR gene have revealed associations with cancer, particularly for the Alu insertion polymorphism, which has been suggested to affect progesterone receptor function and contribute to tumor promotion in the mammary gland.
  
  
  METHODS
  We examined the role of the Alu insertion polymorphism in the PR gene by comparing the genotypes of 209 healthy Mexican women with those of 481 Mexican women with breast cancer (BC).
  
  
  RESULTS
  The genotype frequencies observed in the controls and BC patients were 0% and 4% for T2/T2 (Alu insertion), 16% and 21% for T1/T2, and 84% and 75% for T1/T1 (Alu deletion), respectively. The obtained odds ratio (OR) was 1.7, with a 95% confidence interval (95% CI) of 1.1-2.6, p = 0.009, for the T1/T2-T2/T2 genotypes. The association was also evident when the distributions of the T1/T2-T2/T2 genotypes in patients in the following categories were compared: obesity grade II (OR = 1.81, 95% CI: 1.03-3.18, p = 0.039) and the chemotherapy response (OR = 1.91, 95% CI: 1.27-3.067, p = 0.002).
  
  
  CONCLUSIONS
  The T1/T2-T2/T2 genotypes of the Alu insertion polymorphism in the PR gene are associated with BC susceptibility in the analyzed Mexican population.
authors.affiliation: Laboratorio de Genética Molecular, División de Medicina Molecular, Centro de Investigación Biomédica de Occidente (CIBO), Centro Médico Nacional de Occidente (CMNO), Instituto Mexicano del Seguro Social (IMSS), Guadalajara, Jalisco, México.
authors.forename: Martha Patricia
authors.initials: MP
authors.lastname: Gallegos-Arreola
authors.affiliation: División de Genética, CIBO, CMNO, IMSS, Guadalajara, Jalisco, México ; Doctorado en Genética Humana, CUCS-U de G, Guadalajara, Jalisco, México.
authors.forename: Luis E
authors.initials: LE
authors.lastname: Figuera
authors.affiliation: Laboratorio de Genética Molecular, División de Medicina Molecular, Centro de Investigación Biomédica de Occidente (CIBO), Centro Médico Nacional de Occidente (CMNO), Instituto Mexicano del Seguro Social (IMSS), Guadalajara, Jalisco, México ; Doctorado en Genética Humana, CUCS-U de G, Guadalajara, Jalisco, México.
authors.forename: Liliana Gómez
authors.initials: LG
authors.lastname: Flores-Ramos
authors.affiliation: Laboratorio de Inmunofarmacología, CUCEI, U de G, Guadalajara, Jalisco, México.
authors.forename: Ana María
authors.initials: AM
authors.lastname: Puebla-Pérez
authors.affiliation: Laboratorio de Mutagénesis, División de Medicina Molecular, CIBO, CMNO, IMSS, Guadalajara, Jalisco, México.
authors.forename: Guillermo Moisés
authors.initials: GM
authors.lastname: Zúñiga-González
keywords: Mexican population; PROGINS; breast cancer; polymorphism; progesterone receptor