Related Experiment Video
Updated: Jun 3, 2026

An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
Published on: August 13, 2019
[Hormone therapy and risk for breast cancer in Finnish postmenopausal women]
Heli Lyytinen1, Olavi Ylikorkala
1HYKS:n naistenklinikka, HUS.
Abstract:
Breast cancer is a heterogenous disease and hormonal factors are involved. Since national differences exist in the use of postmenopausal hormone therapy (HT) and other risk factors, associations between HT and breast cancer should be studied nationally. In Finland, estrogen-progestin therapy is associated with higher breast cancer risk than estrogen-only therapy. Also tibolone and levonorgestrel releasing intauterine device combined with estrogen are accompanied with an increased risk of breast cancer. Hormone therapy possibly promotes the growth of the existing undetectable cancer.
Related Concept Videos
Menopause
Hormonal Regulation of the Menstrual Cycle
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
Disorders of the Female Reproductive System
Hormonal Regulation
Hormonal Regulation
Hormonal Control of the Ovarian Cycle
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
