Hemeda R, Sarhan A, Sawy WE, Aidaros M, Gharib A, Hagag H, Farghly A and Ismail K
Background: Obesity increases the risk of 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 aromatase inhibitors on estradiol depletion have been reported. Adjuvant aromatase inhibitors (AIs) therapy is associated with significant bone loss and increased fracture risk in postmenopausal women. Objective: To evaluate the adjuvant aromatase inhibitors therapy in postmenopausal breast cancer patients, focusing on changes in serum estradiol level and bone mineral density (BMD) and their relations to BMI and treatment outcome.
Methods: The present study is a prospective cohort study conducted at the Clinical Oncology and Nuclear Medicine Department, Zagazig University Hospitals between June 2014 and June 2018. This study included 100 postmenopausal women with early breast cancer who received AIs. Patients were classified into 50 non-obese (BMI<25 kg/m2 ) and 50 obese (BMI>25 kg/m2 ) groups. Baseline serum estradiol, FSH and Bone Mineral Density (BMD) levels were obtained for every patient before starting treatment with AIs and 6, 12 and 24 months thereafter. Bone related adverse events, relapse pattern, disease free and overall survival at 2 years were reported and analyzed.
Results: There was significant lowering of serum estradiol level in each group from the pre-treatment values (19.35 ± 7.04 for obese and 17.81 ± 4.25 for non-obese patients) then at 24 months post treatment values (for 11.1 ± 4.12 obese and 10.0 ± 3.17 for non-obese patients) but the difference, in these values between the two groups of patients was not statistically significant. There was reduction in BMD values in both groups over the 24 months follow up time but with no statistically significance. Arthralgia was seen more in obese group 17 patients (34%) than in non-obese 13 (26%). Spontaneous fractures occurred in 3 patients, one of obese and 2 of non-obese patients. Two years disease free survival (DFS) was 82% in obese patients and 93% in non-obese patients with overall survival (OS) equals 92% in obese patients and 95% in non-obese patients.
Conclusion: Within 2 years of adjuvant AIs in postmenopausal women with early breast cancer, there was significant reduction in serum estradiol levels and nonsignificant lowering of BMD in both obese and non-obese patients, the difference in thus values in relation to BMI were not statistically significant. Adverse event related to bone relapse rate and overall survival also showed no statistical difference in relation to BMI.