A few months ago, Raymond-Whish held a traditional Kinaalda ceremony for her daughter, Darby, to mark her passage into puberty. One of the most important Navajo rituals, it celebrates fertility, the natural order and harmony with the earth through song and prayer. Raymond-Whish's mother was there along with dozens of other relatives, and Dyer from the biology department at NAU also attended. For Raymond-Whish, it was a happy, soulful event, but shadowed by the uncomfortable realities of her career in cancer research. From now until late middle age, Darby will produce the large pulses of estrogen that have been linked to breast and other cancers in so many women. And natural harmony, as her mother knows, is not what it used to be, especially now that pollutants are acting like even more estrogen in our bodies. Raymond-Whish can only hope that Darby's cells have the normal number of receptors, and that her genes and her environment haven't somehow conspired to reprogram her development.

"What does artificial estrogen do to the breast?" she asks. "It depends on the time of exposure. If you look at cells of a younger individual who's not yet through puberty, and you expose them to uranium, then that could promote earlier onset of puberty, earlier breast budding. And if they're exposed in the womb, you could be changing the way the receptors are expressed through life."

In breast cancer research in general, there is a fundamental shift from large epidemiological studies that look at women's current lifestyles and exposures to an examination of what the women were exposed to as children. "Most epidemiology starts with the moment a tumor is diagnosed," said Irma Russo, a molecular biologist at the Fox Chase Cancer Center in Philadelphia. "We need to look at when normal cells may have transformed many years earlier."

Suzanne Fenton, a research biologist at the U.S. Environmental Protection Agency, agrees. "We think one of the main drivers of breast cancer is what changes occurred in very early life to alter breast development. It's a fairly radical re-thinking."

Among other experiments, Raymond-Whish is exposing pregnant rats to uranium in order to track what happens in their offspring. When she tried this earlier with mice, the female pups exposed in the womb entered puberty approximately two days earlier, just as they did when exposed to DES. It's a subtle difference, but when combined with other real-life exposures, it may add up.

Explains Fenton: "It's important to remember that breast cancer risk is likely determined by a number of compounds interweaving with genetic factors and not just any one exposure."

Certainly, lifestyles on the reservation have changed in many ways over the past 50 years. "Once upon a time there was no diabetes here, no diverticulitis, no colon cancer," says physician Drouhard. "We are now exposed to the same things you are: plastics, fast food, obesity. Now everybody I know eats at Kentucky Fried Chicken." One way to learn more is by working with all those nose-twitching rodents in the lab. In the coming months, Raymond-Whish will repeat her experiments, prepare to publish again, and spend more time staring at the nauseating giant ovaries on the computer screen. The rats are euthanized before they actually get sick. Still, she says, they do have to offer up their organs to science. It's not easy for her to kill the animals. "Culturally, it's an issue," she says. "But I'm searching for something that's going to help somebody or even lots of people. I always say, 'Thank you for your life.' "

Florence Williams is a 2007-2008 Scripps Fellow at the University of Colorado, where she is researching endocrine disruption and cancer. A former HCN staffer, she currently serves on the HCN board.

This story was funded by a grant from the McCune Charitable Foundation.

Sidebars

A patient

Kathleen Tsosie, who has devoted her life to helping others, now faces the frightening possibility that her breast cancer has returned.

A well

Glenda Rangel and her family grew up drinking from and swimming in water tanks dangerously polluted with uranium.

An activist

Nellie Sandoval, the mother of scientist Stefanie Raymond-Whish, has become an outspoken activist as a result of her own struggle with breast cancer.