A proposed unified mechanism for the reduction of human breast cancer risk by the hormones of pregnancy

Cancer Prevention Research
Herbert I JacobsonThomas T Andersen

Abstract

Parity in women is associated with reduced lifetime risk of breast cancer, and hormones of pregnancy [estrogen (E), progesterone (P), human chorionic gonadotropin (hCG)] are implicated. Parity also reduces mammary cancer risk in carcinogen-exposed rats, and administering pregnancy hormones to these animals is similarly effective. Because pregnancy hormones are also able to stimulate cancer growth, we proposed to resolve this dichotomy by determining whether administered pregnancy hormones elicit the cancer-inhibiting agent alpha-fetoprotein (AFP) from the liver, which would implicate AFP as a proximal effector of hormonal anticancer activity. Accordingly, we treated groups of nitrosomethylurea-exposed rats with saline, E(3), E(2) + P, E(3) + P, hCG, or allowed them to experience pregnancy, and then monitored mammary cancer incidence and serum levels of AFP over time. Each hormone treatment reduced mammary cancer incidence and elevated serum AFP levels. To challenge human tissues, human HepG2 liver cells in culture were treated with the same hormonal agents. Each hormone regimen increased the levels of AFP in the culture medium. Medium containing AFP elicited by hCG inhibited the E(2)-stimulated proliferation of cultured human M...Continue Reading

References

Sep 1, 1977·Journal of Reproduction and Fertility·P C LaiF L Lorscheider
Aug 1, 1990·Journal of the National Cancer Institute·I H RussoJ Russo
Aug 1, 1990·British Journal of Cancer·I H RussoJ Russo
Mar 15, 1985·International Journal of Cancer. Journal International Du Cancer·E J Sarcione, D Hart
May 1, 1989·American Journal of Epidemiology·H I JacobsonD T Janerich
Apr 1, 1980·Proceedings of the National Academy of Sciences of the United States of America·A M Soto, C Sonnenschein
Aug 16, 1984·Biochemical and Biophysical Research Communications·M J VillacampaJ Uriel
Nov 1, 1982·American Journal of Epidemiology·D T Janerich, M B Hoff
Jan 1, 1993·Epidemiologic Reviews·J L KelseyE M John
Oct 24, 1998·American Journal of Epidemiology·B E RichardsonJ A Calvin
Mar 3, 1999·Proceedings of the National Academy of Sciences of the United States of America·R C GuzmanS Nandi
Mar 23, 2000·Biochimica Et Biophysica Acta·F B MesfinT T Andersen
Sep 29, 2001·The Journal of Peptide Research : Official Journal of the American Peptide Society·F B MesfinJ A Bennett
Dec 31, 2002·Expert Review of Anticancer Therapy·Gerald J Mizejewski
Dec 19, 2003·Breast Cancer Research : BCR·Lakshmanaswamy RajkumarSatyabrata Nandi
Dec 3, 2005·Clinical Cancer Research : an Official Journal of the American Association for Cancer Research·Rahul R ParikhThomas T Andersen
Mar 16, 2006·Breast Cancer Research and Treatment·James A BennettThomas T Andersen
May 24, 2008·Advances in Experimental Medicine and Biology·Herbert I JacobsonThomas T Andersen
Oct 9, 2008·Journal of the National Cancer Institute·Bahi TakkoucheMahyar Etminan
Nov 4, 2008·Breast Cancer Research and Treatment·Ya-shuang ZhaoXia Li

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