On Cancer’s Trail [Uranium Linked to Estrogen]

The women in Stefanie Raymond-Whish’s family have a history of breast cancer. Now the young Navajo biologist is asking why.

May 26, 2008

by Florence Williams

High Country News

FLAGSTAFF, ARIZONA

Stefanie Raymond-Whish was 9 years old when her grandmother was diagnosed with breast cancer. A traditional Navajo who raised 15 children after her husband died in a car wreck, Raymond-Whish’s ama’ sa’ ni seldom spoke about her illness. Even after her surgery, when she lived with the grandchildren and their mother, she always acted strong around the kids. It became a pattern: When Raymond-Whish was 13, her 38-year-old mother, Nellie Sandoval, was also diagnosed with breast cancer. And Sandoval was equally reserved on the subject. "My mother was really good about not appearing sick in front of us," says Raymond-Whish, now 32. "As a little girl, I knew about cancer, but didn’t understand the impact of it at the time."

She understood it better by the time she was in college, in Flagstaff, Ariz., when a new tumor appeared in her mother’s other breast. "When my mom had her recurrence, that’s when it really hit me ... it was really upsetting. I went home to Farmington for her lumpectomy." Sandoval survived the disease, but not without a long struggle that included chemotherapy, radiation, and finally a double mastectomy. "My breasts were pretty mangled," says Sandoval, now 58. "So I said, ’Just get rid of them.’ "

Both Sandoval and her daughter have made breast cancer and its impact on Navajos the focus of their lives. Sandoval became an activist and filmmaker, working out of her papaya-colored home in Farmington, N.M. Raymond-Whish has taken her mission a step further: She works as a molecular biologist at the University of Northern Arizona, searching for breast cancer’s root causes. "Is there any difference in how breast cancer develops in Native Americans and non-Native Americans?" she asks. One possible - and provocative - answer is emerging from her lab at the university: uranium.

Scientists have long known that uranium damages human cells. But in over six decades of atomic health testing, no one had ever noticed that uranium, at low doses, can act like an estrogen. No one, that is, until recently, when Raymond-Whish and her coworkers observed some unusual effects in lab animals.

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The lab’s discoveries have already demolished the conventional wisdom on the properties of uranium. Not only does the heavy metal appear to alter mammary cells at very low doses, but it also seems to interfere with normal hormonal signals. Sometimes the uranium follows the same pathways as estrogen, but sometimes it doesn’t, which means it’s triggering other endocrine responses as well. "We don’t yet know the mechanism of how uranium is affecting these cells," Raymond-Whish says, "but we do know an estrogen receptor is involved. We see it in both animals and MCF-7 cells."

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