By Diane Loupe
Tuesday, June 22, 2010
Doctors debate the screening implications of triple-negative breast cancer, a particularly deadly form of breast cancer that strikes earlier, produces larger tumors, resists common treatment and is prevalent among women of West African descent.
(WOMENSENEWS)--After Laurie Stewart's boss died of breast cancer five years ago, she and five other women at the funeral each vowed to do what they could to prevent the disease.
That night, Stewart--who has asked that her first name be changed--found a lump in her breast.
A week later, she learned that she had a particularly nasty type of breast cancer. Hers was "triple negative," meaning it's not traced to any of three common culprits: estrogen, progesterone or human epidermal growth factor receptor 2 (HER2).
Among black women in the United States with breast cancer, the incidence of triple-negative breast cancer is higher and the disease strikes at even earlier ages, spurring some doctors to urge earlier breast cancer screenings. In particular, women of West African descent are more likely to develop triple-negative breast cancer at younger ages with larger tumors.
The median age at diagnosis for triple-negative breast cancer is 53, compared with 58 for other types of cancer, said Dr. Lisa A. Newman, professor of surgery and director of the Breast Care Center at the University of Michigan in Ann Arbor.
At the time she was diagnosed, Stewart said very little was known about the disease and for many it was basically a death sentence. "Just pack your bags, because you're going quick, sister," she said.
Luck was with her, as last November Stewart finished radiation treatment and early this year she got a clean bill of health from her oncologist.
"As far as I know, I'm okay," said Stewart, who is active in online discussion groups sponsored by the Triple Negative Breast Cancer Foundation, based in Norwood, N.J. A central figure on the foundation's board is Malaak Compton-Rock, the model and spouse of comedian Chris Rock and a Women's eNews 21 Leader 2009.
Stewart joins an estimated 30,000 women each year who are diagnosed with this form of breast cancer, according to experts.
Doctors have considered triple-negative breast cancer as a separate subtype for approximately the last decade, said Kathryn J. Ruddy, an oncologist at the Dana-Farber Cancer Institute in Boston.
"Our understanding of the underlying biology of triple-negative disease is somewhat more limited, and some of our triple-negative breast cancer treatments are less well tested," said Ruddy, who is also an instructor at Harvard Medical School.
"Most of us know the words breast cancer, but it's not until the doctor hands us the first pathology report that we hear about triple-negative breast cancer," said Stewart, a kitchen designer in eastern Washington state. "What does this mean?"
One thing it means is a higher rate of mortality.
While most breast cancers develop from the milk ducts, which are lined with epithelial cells, triple-negative cancers seem to arise from basal cells, which lie under the epithelial cells. Basal-cell cancers appear to be more aggressive.
Although only 10 to 20 percent of all breast cancer cases are diagnosed as triple negative, they account for as many as 25 percent of all breast cancer deaths, according to a variety of studies, including one published in 2009 in the Journal of the National Cancer Institute.
"Triple-negative breast cancers are, on average, occurring in younger women, with bigger tumors and the cells are dividing more quickly," said Dr. Rebecca Dent, an assistant professor at the University of Toronto, who also works at Sunnybrook Odette Cancer Center in Toronto. These cancers tend to spread into the lung, brain and liver, and are less likely to go to bone, Dent says.
Since the incidence of this type of cancer is higher among black women, particularly those of West African descent, they should be getting earlier screening for breast cancer, says Dr. Bert M. Petersen, Jr., a leading researcher of triple-negative breast cancer and managing partner of Global Cancer Control in New York City.
Petersen says he finds any way he can to screen African American women for breast cancer starting at the age of 35.
"While white women have the highest rate of breast cancer in this country, African American women have the highest rate of breast cancer under the age of 50," said Petersen. Black women are the least likely to be screened for breast cancer, he adds.
Newman recommends that African American women get mammograms starting at age 40. Among women with a strong family history of early onset breast cancer, Newman recommends starting mammograms when a woman is five to 10 years younger than the youngest age of a breast cancer diagnosis in her family.
But the push for earlier screening is controversial.
Dr. Ned Calonge, chairman of the U.S. Preventive Services Task Force and chief medical officer of the Colorado Department of Public Health and Environment, says early detection does not necessarily extend lives.
Calonge's group, which provides recommendations on a wide range of preventive services, ignited a firestorm of criticism last year when it recommended against routine screening mammography for women under the age of 40. The group argued that these screenings are more likely to result in false-positive test results, over diagnosis and unnecessary earlier treatment.
Routine mammograms for women between the ages of 40 and 50 are associated with a 15 percent reduction in mortality, according to a study looking at eight years of data that was published in November in the Annals of Internal Medicine.
"This means that of seven women who participate in mammographic screening and have breast cancer, six will die of their breast cancer, in spite of mammography," Calonge said.
Despite the tentative status of the research into triple-negative breast cancer, University of Michigan's Newman argues in favor of more, earlier screening. For one thing, mammography technology was not as sophisticated in previous trials, Newman says.
"There are many reasons to suspect that the benefits of mammography may actually be substantially greater for younger age women as well as for older age women compared to what was documented in those older studies," she said.
Unless women have a significant family history, it may be difficult for African American women under the age of 40 to get screened, says Global Cancer Control's Petersen. Some insurance plans won't cover diagnostic mammograms at this age, unless accompanied by some other symptom, such as breast pain.
To learn more about the disease, Petersen plans to start collecting tissue of women in West Africa who have been diagnosed with breast cancer. He is talking with Ghanaian officials to create a tissue bank of normal tissue, not just to study breast cancer, but other diseases prevalent among those of African ancestry, such as hypertension, diabetes and tuberculosis. Such data could lead to more effective ways to treat these diseases.
Diane Loupe is a freelance writer and editor in Decatur, Ga.
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