The expression of the estrogen receptor in obese patients with high breast density (HBD).

Objective: Obesity has been associated with increased risk for breast cancer (BC) mortality. Verifying in women with high breast density (HBD) post-menopausal, the frequency of polymorphisnns of estrogen receptor (ER)alpha-Pvull, ER alpha-Xbal and if they influence the body mass index (BMI). Methods: Study with 308 women with HBD post-menopause divided into two groups according to BMI: 1st group = BMI <25 kg/m(2), 2nd group = BMI >= 25 kg/m(2). It was characterized in the clinical history: menarche, menopause, parity, family history of BC, smoking and alcohol intake. Results: Allele and genotype frequencies for the ER alpha-397-Pvull and ER alpha-351-Xbal: P =43.99%, p =56.01%, pp =32.14%, Pp =47.73%, PP =X =20.13% and X=41.56%, x=58.44%; xx = 33.44%; Xx =50.00%; XX =16.56%, respectively. Both Pvull and Xbal influenced BMI. When Xbal is mutated the tendency is toward higher BMI (0.039), and women with lower BMI were more frequent in Pvull genotype (p = 0.002). More frequent risk factors for BC: menarche before the age of 12 years (35.38%), nulliparity or 1st child after 28 years old (41.66%), family history of BC (19.16%) and overweight/obesity (62.01%). Conclusion: Variations in the ER alpha gene affected the BMI in women with HBD, who already are at increased risk for BC.