Perinatal factors increase breast cancer risk

Area of Science:

• Endocrinology
• Developmental Biology
• Oncology

Background:

• Breast cancer may originate in early life, with prenatal exposures potentially increasing offspring risk.
• Maternal behaviors such as high-fat diet, alcohol intake, and stress are linked to higher breast cancer incidence.

Purpose of the Study:

• To investigate the impact of early life exposures on mammary tumor development.
• To explore the role of maternal diet and stress in offspring breast cancer vulnerability.
• To understand the mechanisms underlying early estrogen action on mammary tumorigenesis.

Main Methods:

• Neonatal handling of rats to improve stress coping abilities.
• Maternal high-fat diet exposure during pregnancy.
• Induction of mammary tumors using 7,12-dimethylbenz(a)anthracene (DMBA).
• Analysis of serum 17 beta-estradiol (E2) levels.
• Studies in transgenic mice overexpressing transforming growth factor alpha (TGF alpha).

Main Results:

• Neonatal handling reduced DMBA-induced mammary tumors in rats.
• Maternal high-fat diet increased DMBA-induced mammary tumors in female offspring.
• High-fat diet elevated maternal serum E2 levels, suggesting a role for in utero estrogens.
• Transgenic mice showed elevated E2, stress intolerance, alcohol intake, and tumors.

Conclusions:

• Early life exposures, particularly in utero estrogen concentrations, critically influence breast cancer vulnerability.
• Maternal diet and stress can alter offspring's susceptibility to mammary tumors.
• Animal models are valuable for studying the timing of risk behaviors and early estrogen effects on breast cancer.