Related Experiment Video
Updated: Jun 4, 2026

06:18
An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
Published on: August 13, 2019
Estrogens in the postmenopausal woman.
Canadian Family Physician Medecin De Famille Canadien
|February 10, 2011
Summary
Recent studies suggested a link between estrogens and cancer, but this review found no evidence to support this claim. Further research explores estrogens
Area of Science:
- Endocrinology and Oncology
- Medical Journalism Ethics
Background:
- Widespread media reports in 1975-1976 linked estrogens to cancer, primarily citing articles in the New England Journal of Medicine.
- Public health concerns and medical discourse were significantly influenced by these publications.
Purpose of the Study:
- To critically evaluate the scientific evidence for and against a causal relationship between estrogens and cancer.
- To review the established effects of estrogens on osteoporosis, thromboembolism, and arteriosclerosis.
Main Methods:
- Comprehensive review of existing scientific literature and published studies on estrogen-cancer relationships.
- Analysis of the evidence presented in key medical journal articles from 1975-1976.
Main Results:
- The review found no scientific basis to support the accusation of a causal link between estrogens and cancer.
- Established associations between estrogens and other conditions like osteoporosis, thromboembolism, and arteriosclerosis were examined.
Conclusions:
- The purported link between estrogens and cancer lacks sufficient scientific evidence.
- Estrogen's role in other physiological and pathological processes requires continued investigation.
Related Concept Videos
Menopause
Menopause, a natural biological process marking the end of a woman's fertility, typically occurs between the fifth and sixth decade of life. This phase is characterized by the exhaustion of the ovarian follicle pool, leading to less responsive ovaries despite the high levels of Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH). The consequential decrease in estrogen production results in symptoms like hot flashes, heavy sweating, headaches, hair loss, muscle pains, vaginal...
Hormonal Regulation of the Menstrual Cycle
The ovarian cycle regulates endometrial changes throughout a single menstrual cycle via the coordinated action of gonadotrophin-releasing hormone (GnRH) and gonadotrophins.
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.
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.
Hormonal Control of the Ovarian Cycle
The ovarian cycle is meticulously regulated by the hypothalamic-pituitary-gonadal axis. This cycle orchestrates the release of a mature oocyte, essential for reproduction.
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...
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...
Gonadal and Placental Hormones
The gonads, namely the testes in males and the ovaries in females, are pivotal in producing gonadal hormones that orchestrate the intricate processes of sexual development and reproduction.
In males, testosterone is the primary gonadal androgen. It plays a central role in the maturation of male reproductive organs — the penis and testes. Additionally, testosterone is instrumental in the development of secondary sexual characteristics — a deep voice as well as facial and pubic hair growth — and...
In males, testosterone is the primary gonadal androgen. It plays a central role in the maturation of male reproductive organs — the penis and testes. Additionally, testosterone is instrumental in the development of secondary sexual characteristics — a deep voice as well as facial and pubic hair growth — and...
Oogenesis
In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from the equivalent procedure of spermatogenesis in males. First, meiotic divisions during oogenesis are asymmetric, meaning that a large oocyte (containing most of the cytoplasm) and minor polar body are produced as a result of meiosis I, and again following meiosis II. Since only oocytes will go on to form embryos if fertilized, this unequal...
Oogenesis
Oogenesis, the process of developing egg cells (female gametes), occurs within the ovaries and is fundamental to female fertility. This sequence begins during fetal development when diploid oogonia in the developing ovaries undergo mitotic divisions to produce primary oocytes. By birth, these primary oocytes enter prophase I of meiosis but become arrested in this stage, remaining suspended until puberty.
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is known...
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is known...
