Germline EDC Exposure &amp; Breast Cancer Risk in the 3Gs Study
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: Non-technical overview of the research topic and relevance to breast cancer: A mother’s exposure to
 environmental chemicals during pregnancy can affect three generations: the mother, her daughter in the
 womb, and the daughter’s reproductive cells that will create the granddaughter. These are three life stages (or
 windows) when the breast is susceptible to errors that can cause cancer later. Chemicals that disrupt the
 endocrine system (EDCs) are suspected to cause problems during these windows. The Child Health and
 Development Studies have found that exposure to the pesticide DDT either in pregnancy or in the womb
 predict breast cancer. In this project we propose the first study to test if the grandmother’s DDT exposure can
 impact breast cancer risk in her granddaughter. This study requires observing three generations over nearly 60
 years. Data like this are rare, but there is one opportunity for this research in California: the Child Health and
 Development Studies (CHDS). The CHDS enrolled 20,000 pregnant women in the Kaiser Foundation Health
 plan in the 1960s and has continued to follow these families for three generations. The original CHDS mothers
 are now grandmothers in their 70s, the CHDS daughters are now in their 50s, entering the period of substantial
 breast cancer risk, and the CHDS granddaughters are in their 20s, before the primary period of risk. This
 allows us to examine characteristics and exposures that precede the initiation of breast cancer in the
 granddaughters. In particular, we can test whether EDC exposure during the grandmother’s pregnancy is
 linked to age at menarche (first menstrual period) in her granddaughters. Age at menarche is an established
 early risk factor for breast cancer. Young age at menarche predicts breast cancer after menopause, and older
 age at menarche predicts breast cancer before menopause.
 
 
 Research question(s) or central hypotheses: We will test the hypothesis that EDCs found in the pregnancy
 serum of the grandmother’s generation predict age at menarche in the granddaughter’s generation.
 
 
 General methodology: The study population is the unique three-generation breast cancer study (3Gs) based
 on the CHDS and funded by the California Breast Cancer Research Program Special Research Initiative. The
 3Gs Study collected data on the daughter’s and granddaughter’s generations of the CHDS. The 363
 granddaughters who were over age 18 and reported their age at menarche are the basis of the proposed
 study. We will measure the grandmothers’ exposure to EDCs in pregnancy using stored serum samples,
 allowing us to directly measure exposure without depending on participants recalling exposures 60 years ago.
 
 
 Innovative elements: This will be the first study to link the grandmother’s exposures to EDCs during
 pregnancy with the granddaughter’s age at menarche, a risk factor for breast cancer. CHDS members in three
 generations will work with researchers and our community partner to design prevention messages, a unique
 collaboration.
 
 
 Advocacy involvement and relevance to the human issues associated with breast cancer: We need to
 know if EDCs, such as chemicals like DDT, can affect multiple generations. Although DDT is now banned in
 the US, the three generations exposed to high levels of DDT during pregnancies in the 1960s are still alive.
 There were many other EDCs used in the 1960s and many continue to be used. We need to understand
 whether EDCs have the capacity to affect reproductive cells, because these cells are passed down the line to
 many generations to come. If we see an effect on the granddaughter’s age at menarche, this study will show
 the potential of EDCs to impact the breast cancer risk of many generations. If we have this information, it may
 lead to changes in behavior and also community decisions to protect future generations by limiting EDC
 exposure. We will design a careful education campaign that is appropriate for three generations of women:
 grandmothers (age 70), daughters (age 50) and granddaughters (age 20). To accomplish this we will work with
 Zero Breast Cancer (Catherine Thomsen), our community partner, and will also consult with the Participant
 Advisory Council (PAC) of the CHDS, which currently has members from the first two generations;, this
 proposal will fund contribution and input from the third generation. With Catherine Thomsen’s leadership, we
 will craft a series of digital messages to explain how women can protect themselves and future generations
 from potential harmful exposures.