Related Experiment Video

Updated: Jul 9, 2026

Changes in Mammary Gland Morphology and Breast Cancer Risk in Rats
09:36

Changes in Mammary Gland Morphology and Breast Cancer Risk in Rats

Published on: October 16, 2010

Pregnancy and the risk of breast cancer

Kara Britt1, Alan Ashworth, Matthew Smalley

  • 1Institute of Cancer Research,, The Breakthrough Breast Cancer Research Centre, 237 Fulham Road, London SW3 6JB, UK. kara.britt@icr.ac.uk

Endocrine-Related Cancer
|November 30, 2007
PubMed

It is well established that childless women and women having children later in life are at an increased risk of developing breast cancer. In particular, women having a first child before 20 years of age have a 50% reduction in lifetime breast cancer risk when compared with women who do not have children. This protective effect is specific for estrogen receptor positive breast cancer. Nevertheless, it remains unclear how parity decreases breast cancer risk. Possible mechanisms of action include changes to the hormonal profile of parous women, a more differentiated and so less susceptible mammary gland or changes within specific epithelial cell subpopulations. In this review, we discuss the epidemiological evidence for the protective effects of parity on breast cancer. We also explore the mechanisms by which parity protects, with a particular emphasis on the role of stem cells and the interactions between stem cells and estrogen.

More Related Videos

In Vivo and Ex Vivo Approaches to Study Ovarian Cancer Metastatic Colonization of Milky Spot Structures in Peritoneal Adipose13:04

In Vivo and Ex Vivo Approaches to Study Ovarian Cancer Metastatic Colonization of Milky Spot Structures in Peritoneal Adipose

Published on: October 14, 2015

Related Concept Videos

Cancer Prevention02:59

Cancer Prevention

Several factors can increase the risk of cancer in an individual. About 50% of cancer cases can be prevented by adopting a healthy lifestyle, regular exercise, eating healthy, and following a modest cancer prevention diet. Epidemiological studies have consistently shown that populations with vegetable and fruit-rich diets have reduced the incidence of cancer. On the other hand, populations who have a diet rich in animal fat, red meat, junk food, or high calories are predisposed to cancer.
Some...
Cancer Prevention02:59

Cancer Prevention

Several factors can increase the risk of cancer in an individual. About 50% of cancer cases can be prevented by adopting a healthy lifestyle, regular exercise, eating healthy, and following a modest cancer prevention diet. Epidemiological studies have consistently shown that populations with vegetable and fruit-rich diets have reduced the incidence of cancer. On the other hand, populations who have a diet rich in animal fat, red meat, junk food, or high calories are predisposed to cancer.
Some...
Disorders of the Female Reproductive System01:24

Disorders of the Female Reproductive System

The female reproductive system can be affected by several disorders, including Premenstrual Syndrome (PMS), Premenstrual Dysphoric Disorder (PMDD), endometriosis, and various forms of cancer. PMS and PMDD are cyclical conditions that cause physical and emotional distress, with symptoms that include edema, mood swings, and food cravings. PMDD is a more severe form of PMS characterized by increased symptom severity that peaks during the luteal phase and tends to improve or resolve shortly after...
Psychoneuroimmunology: Diabetes and Cancer01:19

Psychoneuroimmunology: Diabetes and Cancer

Chronic stress has been linked to both the onset and progression of serious health conditions, including Type 2 diabetes and cancer. Type 2 diabetes, a widespread chronic illness, is closely associated with obesity and insulin resistance, both of which often worsen under stress. Studies indicate that men experiencing high levels of chronic stress face a 45% higher risk of developing diabetes compared to those with minimal stress. Stress triggers physiological responses that elevate blood...
Pathophysiology of Diabetes01:20

Pathophysiology of Diabetes

Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycemia. The four categories of diabetes are type 1 diabetes, type 2 diabetes, other specific types of diabetes, and gestational diabetes.
Type 1 diabetes is characterized by autoimmune-mediated destruction of pancreatic β cells, with environmental factors potentially triggering this process in genetically susceptible individuals. Despite many not having a family history, certain genes increase susceptibility, suggesting a...
Teratogenicity01:07

Teratogenicity

The ability of a drug to produce structural deformations and functional abnormalities in the developing embryo or the fetus is called teratogenicity, and the drug producing this effect is known as a teratogen. Teratogenic effects include stillbirth, miscarriage, intrauterine growth restriction, and neurocognitive delay. A teratogen may affect the embryo at different stages of development, which is important in determining the type and extent of the damage. During blastocyst formation, the early...