Breast Cancer's Color Divide
WHY YOU SHOULD CARE
Because understanding the race gaps in breast cancer is our first step in closing them, and saving more lives in the process.
By Melissa Pandika
“I started doing calculations in my head,” remembers Melanie Nix. At 38, she’d been diagnosed with triple-negative breast cancer — an especially aggressive form that disproportionately strikes African-American women. Breast cancer had killed her own mother, and Nix figured, “If I died at the age my mother did, that only gave me 11 years with [my kids].”
After chemotherapy and a double mastectomy, Nix now lives cancer-free with her family in Maryland, but she considers herself lucky. Black women are 41 percent more likely than white women to die of breast cancer, according to the Centers for Disease Control. Black and Latina women seem to be diagnosed with breast cancer at a more advanced stage, according to a recent Cancer Epidemiology, Biomarkers & Prevention study. And for reasons still unclear, triple-negative breast cancer affects Black women three times more than it does white and Latina women. Promising new research could help narrow these disparities. In a newly released TED Talk, for instance, MIT chemical engineer Paula Hammond discusses her efforts to design nanoparticles that weaken the defenses of drug-resistant triple-negative breast cancer tumors.
But where do the disparities come from in the first place? Experts blame everything from poor health care access to physician bias — which is to say that cultural, social and economic factors may count for more than biological ones. Linda Goler Blount, president and CEO of the Black Women’s Health Imperative, points to the “lived experiences of Black women.” These include barriers to prevention, disparities in treatment and prevention and a lack of research.
In low-income communities of color, breast health often remains enshrouded in myth. (Blount recalls one woman who thought mammograms caused cancer to spread.) Black women also have denser breast tissue, which can obscure mammography results. Blount notes that low-income hospitals typically don’t house advanced technology to screen dense breast tissue.
Disparities also pervade treatment. Lu Chen, author of the Cancer Epidemiology study, found that Black and Latina women were 30 to 40 percent more likely than white women to receive inappropriate treatments. Earlier research suggests that physicians might not share certain treatment options with Black patients, since they might view them as less likely to comply than white patients. But doctors might also lack knowledge about racial differences in breast cancer, like how young Black women have a higher risk of suffering from the aggressive triple-negative subtype. Given her family history of breast cancer, Nix sought a mammogram in her mid-20s, but her doctor “was very dismissive,” insisting she was “too young.”
There also just isn’t as much research on minorities. A 2014 Cancer study found that less than 2 percent of clinical cancer trials focus on people who are not white. Of the $74 million the American Cancer Society is investing in breast cancer grants, around $500,000 funds grants specially concerned with triple-negative breast cancer, although spokesperson David Sampson notes that the society doesn’t fund projects based on subtype and that scientists themselves choose promising areas of research. Minorities also remain underrepresented in cancer trials: Blacks and Latinos have the lowest rates of cancer clinical trial participation. They face a number of barriers, such as transportation. Many are also wary of the ivory tower, says Oscar Streeter, a medical director at the Center for Thermal Oncology. “How many people have asked that community, ‘What do you want?’”
Still, some researchers are racing to thwart cancer subtypes that disproportionately affect racial minorities, like triple-negative breast cancer. Triple-negative tumors lack the three receptors most commonly targeted by currently available drugs, making treatment especially challenging. Hammond has designed a multilayered nanoparticle that silences the genetic mutations that normally allow these tumors to survive chemotherapy. Her superweapon consists of a core capsule containing chemo drugs, wrapped in a thin layer of a molecule called siRNA to silence the survival genes. A third polymer layer protects the siRNA from degradation, while the outermost layer renders it invisible to the immune system and binds to tumor cells, which then take up the nanoparticle. Hammond says she hopes to move forward with applying for human trials in the next three or four years.
Blount thinks Hammond’s work has “potential for reducing disparities — if people have access to it.” Nix, who has a daughter, remains hopeful. “It’s most encouraging as a mother … It may not even be an issue for my kids in their lifetime.”
- Melissa PandikaContact Melissa Pandika