Every day we are exposed to chemicals, many of which are found in the consumer products we use. As girls go through puberty and their breasts develop, the mammary tissue becomes particularly susceptible to these environmental influences because the breast cells are dividing rapidly. So it is crucial that we understand which chemicals are best to avoid during this important period of life.
To explore this issue, we have launched the Early Life exposures in Latina Adolescents (ELLA) project—an innovative and timely research project focused on the impact of environmental chemicals on breast development in adolescent girls and how this may influence breast cancer risk later in life. The study is a collaboration between four major research institutions: Brigham and Women’s Hospital/Harvard Medical School, Fox Chase Cancer Center, University of Chile, and Silent Spring Institute.
The project is innovative because it is the first study ever to conduct breast density assessments in young teenage girls using a novel low dose x-ray technology called DXA (Dual-energy X-ray absorptiometry). With these assessments, we will be able to see how changes in breast composition track with exposures to certain common chemicals. ELLA is also timely because, in recent years, we have come to appreciate more than ever the fact that breast cancer is a disease that may originate early in life. Evidence is accumulating that perinatal and early life factors can affect the risk of breast cancer in later life. Now, we’re beginning to understand that puberty is also an important “window of susceptibility”—much more important than we previously realized.
The beauty of the ELLA study is that we are exploring these environmental exposures in an ongoing cohort of 500 young teenage girls in Chile. These girls have been followed since the age of four as part of a long-term project called the Growth and Obesity Cohort Study. I was in Chile recently and had the privilege of meeting some of our young study participants. I was very impressed with the girls’ attitudes toward making a contribution to research. They visit the study center on a regular basis and for many of them the exams have become a routine part of their lives. The prospect of participating in cutting-edge research and helping to advance science aimed at preventing breast cancer is both exciting and empowering to the girls.
Another key aspect of the project is that the study in girls is paralleled with an animal study, where we have the luxury of a controlled experimental setting. The animals will be exposed to chemicals (the same as those we are measuring in the girls) during the equivalent of their puberty, and the effects on their mammary gland morphology and their breast cancer risk will be examined. These animal experiments will be conducted at the world renowned laboratory of Professor Jose Russo who has been a leader in mammary gland morphology for several decades.
Results from our study will be disseminated in the U.S. through Silent Spring Institute, which has unique expertise in communicating the impacts of environmental chemicals on health, and to the Chilean population through our collaborators at the University of Chile in Santiago. A Parent Advisory Council in Santiago was recently formed to help engage participating families and the larger community. The girls will also be involved in helping to develop educational and outreach materials focused on environmental chemicals and reducing breast cancer risk through healthy activities.
This is an exciting and unique project, the results of which could have a tremendous impact on our understanding of the influence of chemicals during this critical period of development, on breast cancer prevention, and on public health overall.
Karin Michels is a professor and Chair of the Department of Epidemiology at UCLA Fielding School of Public Health. She is a principal investigator and the project leader for ELLA.