Black Women Are Prone To Aggressive Type Of Cancer

Lorie Williams thought for months that she might have a lump in her breast. But when the doctor said it was cancer, she was still stunned. After all, she was just 29 years old, no one in her family had ever had breast cancer, and she had never heard of anyone getting the disease so young.

"I was just numb," said Williams, who lives in Holly Springs, N.C. "I couldn't believe it was really happening. Then I just became hysterical."

Women such as Williams have become the focus of an intense effort to solve one of the most pressing mysteries about breast cancer: Why are black women, who are less likely to get the disease than white women, more likely to get it when they are young - and much more likely to die from it?

Now, researchers have uncovered a crucial clue: Black women, particularly young ones, get hit much more often by an aggressive form of breast cancer that is invulnerable to many of the latest treatments.

That discovery, however, has raised a thicket of questions and an intense debate. Are black women prone to the deadlier cancer for genetic reasons? The same deadly form of breast cancer turns out to be extremely common in parts of Africa where the slave trade was centered, indicating that genes play a role. Researchers also have found evidence that other factors, such as breast-feeding patterns, may be key.

The emerging picture of breast cancer marks a transforming development in the battle against the disease, some experts say, particularly for black women.

"It's a sea change for how we think about the problem of breast cancer in African-American women," said Rowan T. Chlebowski, who studies breast cancer at Harbor-UCLA Medical Center. "It's really changing the debate."
'Triple-Negative' Cancer Traced

Researchers have long thought that the reason black breast cancer patients were more likely to die was the stubborn inequities in the quality of care that minorities receive. Black women tend to get fewer mammograms, to get their diagnosis after their cancer has spread and to receive less aggressive treatment once diagnosed, many studies have shown.

Those factors do play a significant role. But recent research has found that even when everything is equal, black women are less likely to survive.

At the same time, researchers using the latest molecular tools have discovered that breast cancer comes in at least five variations. One, called "triple-negative" because it lacks three key markers that distinguish tumors, grows quickly, recurs more often and kills more frequently. It is much harder to prevent and treat because it does not respond to the newest drugs, including those that block estrogen and targeted therapies such as Herceptin.

A key insight came last year when a detailed genetic analysis of 496 breast tumors showed that a "basal-like" form of triple-negative cancer was startlingly more common among young black women, accounting for 39 percent of their cancers, compared with 16 percent of white women's.

"We found an important piece of the puzzle," said Lisa A. Carey of the University of North Carolina, who led the study. "This indicates that biology is important."

Other studies subsequently confirmed the findings, including one published last month that found triple-negative tumors about twice as often among black women as among white women. It also found that triple-negative is also more frequent in Hispanics than in whites, though still less common than in blacks.

Some researchers, suspecting that the higher rate among African-Americans might stem from a genetic predisposition, have begun studying women in parts of Africa. They discovered that triple-negative is extremely common, accounting for some 70 percent of breast cancers in women tested in Nigeria and Senegal, for example.

"This suggests that there may be a genetic contribution," said Olufunmilayo Olopade of the University of Chicago, who is leading the research. "Is it because of genes common to African ancestry? Maybe there's a genetic contribution that we didn't appreciate."
Breast-Feeding Is A Variable

But other research suggests that social factors may be more crucial. One study published online this week, for example, found that women who did not breast-feed their children are especially prone to triple-negative cancer.

"Our data show that is has nothing to do with genetics but really has to do with environmental factors," said Robert Millikan of the University of North Carolina, noting that black women are less likely than white women to breast-feed.

source : www.tbo.com