The typical U.S. woman diagnosed with breast cancer is about 60 years old. She’s also white and affluent, at least according to government data.

But breast cancer defies statistics every day.

Katherine Henderson, left, discusses ongoing studies with Leslie Bernstein (Photo by p.cunningham)

The disease can touch almost any adult woman, whatever her ethnicity or age.

And when cancer develops in women younger than 50, it tends to be more aggressive. The outcome likely will be poorer, too.

Yet scientists have run relatively few breast cancer studies looking at younger women, so they are unsure why some of them develop breast cancer, why it is so invasive and how to reduce their risk for it.

City of Hope’s Katherine Henderson, Ph.D., assistant research professor in the Division of Cancer Etiology, is tackling this complex issue through her role in the Young Women’s Health History Study (YWHHS).

Michigan State University researchers head up YWHHS, and Henderson leads data collection for women in Los Angeles County who are participating in the study.

“This area is ripe for research, because there is so much we still need to learn about the risk factors for breast cancer in this younger population,” Henderson said. She hopes the work will lead to strategies to improve women’s chances of avoiding disease.

YWHHS researchers will study 1,000 African-American and 1,000 white women diagnosed with breast cancer before age 50 from 2010 to 2014. They’ll compare the women — all of whom come from Los Angeles County and metropolitan Detroit — to 2,000 similar women without breast cancer.

Scientists will focus on factors related to “energy balance” during childhood and adulthood. They’ll look at each woman’s diet and exercise habits over time, as well as patterns in growth, body fat and how her body matured during puberty. The team also will examine insulin resistance — a diabetes-associated condition in which the body’s cells cannot adequately use insulin to absorb blood sugar.

And by looking at women’s DNA, the scientists will try to determine if common genetic differences related to energy balance may be linked to breast cancer development.

In addition, recent research suggests that women with less education and income also may be more likely to develop certain aggressive breast cancers. Through YWHSS, scientists hope to better understand the relationships between energy balance factors and risk for these aggressive tumors, as well as breast cancer risk overall.