EFFECT OF OBESITY ON ESTRADIOL DEPLETIONIN POSTMENOPAUSAL WOMEN WITH HORMONE-SENSITIVE EARLY BREAST CANCER TREATED WITHADJUVANT ANASTRAZOLE.

Background: Obesity increases the risk of all-cause and breast cancer mortality. As obese patients have higher levels of aromatase enzyme activity, conflicting results on the effect of body mass index (BMI) with the standard dose of Anastrazole on estradiol depletion have been reported.Aim of the work:The aim of this study was to assess the Effect of obesity on estradiol depletion in postmenopausal women with hormone-sensitive early breast cancer treated with Adjuvant Anastrazole Patients and Methods:The present study is a prospective cohort study conducted at the Clinical Oncology and Nuclear Medicine Department -Zagazig University Hospitals between June 2013 and June 2015. The study included 100 postmenopausal women with hormonal receptors positive early breast cancer who received Anastrazole as an upfront adjuvant treatment with standard dose of Anastrozole 1mg/d . Patients were classified into two groups according to BMI, normal weight or non obese (BMI<30kg/m2) and obese (BMI?30kg/m2) according to the WHO and a baseline serum estradiol and FSH were obtained for every patient prior starting Anastrazole therapy. Patients were followed up and monitored after 6 months for changes in serum estradiol, and FSH . Results:One hundred patients were included, half of them were classified being obese with (BMI?30) with mean BMI(35±5.8) while the other half was considered non obese (BMI<30) mean BMI(24.5±4.4). Both groups were compared regarding patient measures and tumor characteristics, regarding all ( 100 ) patientsAnastrazole significantly redued the mean ESL from19.45±4.1 ?pg?ml?1 to 11.13 ±3.1 ?pg?ml?1 after 6 months of treatment (P <0.001). On the other hand, inverse changes in FSH serum levels as the mean FSH serum level initially was 70.91±20.7?mIU?ml?1 and then significantly increased to 75.78±19.3?mIU?ml?1 after 6 months of treatment with Anastrazol (P <0.001). however after 6 months of Anastrazole treatment the mean ESL of obese patients was significantly higher in obese compared to non-obese patients (11.95 ?pg?ml?1 VS 8.78?pg?ml?1 ) (P <0.001). and this difference reflected by significantly low serum FSH level compared to non-obese patients(64.98±14.7?mIU?ml?1 vs 87.53±17.6?mIU?ml?1) (P <0.001). Conclusion: Anasrazole is less effective in suppressing the ESL in obese when compared with non-obese patients.