Title:Circulatory Estrogen Level Protects Against Breast Cancer in Obese Women
VOLUME: 8 ISSUE: 2
Author(s):Zsuzsanna Suba
Affiliation:National Institute of Oncology, Surgical and Molecular Tumor Pathology Centre, Address: H-1122 Rath Gyorgy str. 7-9, Budapest, Hungary.
Keywords:Androgen, breast cancer risk, estrogen, insulin resistance, menopause, metabolic syndrome, obesity, type-2 diabetes,
visceral adiposity
Abstract:Literary data suggest apparently ambiguous interaction between menopausal status and obesity-associated
breast cancer risk based on the principle of the carcinogenic capacity of estrogen. Before menopause, breast cancer incidence
is relatively low and adiposity is erroneously regarded as a protective factor against this tumor conferred by the
obesity associated defective estrogen-synthesis. By contrast, in postmenopausal cases, obesity presents a strong risk factor
for breast cancer being mistakenly attributed to the presumed excessive estrogen-production of their adipose-tissue mass.
Obesity is associated with dysmetabolism and endangers the healthy equilibrium of sexual hormone-production and regular
menstrual cycles in women, which are the prerequisites not only for reproductive capacity but also for somatic health.
At the same time, literary data support that anovulatory infertility is a very strong risk for breast cancer in young women
either with or without obesity. In the majority of premenopausal women, obesity associated insulin resistance is moderate
and may be counteracted by their preserved circulatory estrogen level. Consequently, it is not obesity but rather the still
sufficient estrogen-level, which may be protective against breast cancer in young adult females. In obese older women,
never using hormone replacement therapy (HRT) the breast cancer risk is high, which is associated with their continuous
estrogen loss and increasing insulin-resistance. By contrast, obese postmenopausal women using HRT, have a decreased
risk for breast cancer as the protective effect of estrogen-substitution may counteract to their obesity associated systemic
alterations. The revealed inverse correlation between circulatory estrogen-level and breast cancer risk in obese women
should advance our understanding of breast cancer etiology and promotes primary prevention measures. New patents recommend
various methods for the prevention and treatment of obesity-related systemic disorders and the associated breast
cancer.
