Association of serum leptin with serum estradiol in relation to breast carcinogenesis: a comparative case-control study between pre- and postmenopausal women

Background/aim: The aims of this study were to observe the interhormonal relationship of serum leptin with serum estradiol and to compare pre- and postmenopausal women for possible implications in breast carcinogenesis. Materials and methods: This comparative case-control study encompasses 175 breast cancer patients and 175 age-, sex-, and BMI- matched healthy controls. For comparison, the subjects were divided into pre- and postmenopausal groups according to their menstrual history. Blood samples were analyzed for serum leptin and serum estradiol by the ELISA method. Results: Higher mean values of serum estrogen and leptin were observed in breast cancer cases among both the pre- and postmenopausal groups. While estimating the association of serum leptin with serum estradiol, a weak positive (r = 0.186) but statistically significant (P = 0.022) correlation was found among the premenopausal subjects, while a moderate positive association (r = 0.556) was found among the postmenopausal subjects, which had high statistical significance (P = 0.001). Furthermore, correlation coefficients (r) of the pre- and postmenopausal groups were compared using Fisher r-to-z transformation and found to have a statistically significant difference (z = 4.03, P = 0.0001). Conclusion: The findings of this study suggest the mitogenic effects of leptin on mammary tissue via augmenting peripheral estrogen production more significantly among postmenopausal subjects. Thus, the therapeutic modulation of leptin may be a potential adjuvant treatment for breast cancer patients with high levels of leptin along with high estrogen concentration as a consequence.