Our food and environment has increasing amounts of hormone disruptors and imitators. I understand it's even in the air, from cars burning gasoline with ethanol in it which was made from GMO corn.
You might believe it, but you don't understand it, as it isn't true. There is a lot of fear mongering about gmos, and it unfounded.
You clearly have not looked into it. I recommend starting with the heavily documented book, "Altered Genes, Twisted Truth" by Steven M. Druker, ISBN-13 978-0-9856169-0-8, and the documentary video, "Seeds of Death," available at
https://www.youtube.com/watch?v=aFVF3MJNOHg . Druker, author of the book, is a public-interest attorney who initiated a lawsuit that forced the FDA to divulge its files on genetically engineered foods. This exposed how the agency had covered up the warnings of its own scientists about the risks, lied about the facts, and then ushered these foods onto the market in violation of federal law. He has served on the food-safety panels at conferences held by the National Research Council and the FDA, presented lectures at numerous universities, met with government officials throughout the world, and conferred at the White House Executive Offices with a task force of President Clinton's Council on Environmental Quality.
I don't know how much might be known about GMOs' effects on breast growth, but they definitely do a lot of other damage, and my wife and I are avoiding them for many reasons. One of the reasons to genetically modify a plant is to make it able to tolerate a lot of weed killer and pesticide; but then people ingest these weed killers and pesticides, resulting in health problems. Also, they kill helpful bacteria in the soil that convert the nutrients into forms the plant can absorb; so even if the plant looks big and green, it won't have the nutrition it should. Next, these chemicals impair humans' ability to absorb what little nutrition there might be left in the plant, so we get even less.