For years, Dr. Judith Hurley had noticed something odd in her Bahamian breast cancer patients — they were all so young. Most American women are diagnosed with breast cancer in their 60s, but many of Hurley’s patients had not even reached menopause.
“When you have an observation, you have to start chasing it,” said Hurley, an oncologist at Sylvester Comprehensive Cancer Center in the University of Miami Miller School of Medicine.
Since 2002, Hurley has studied racial and ethnic disparities in breast cancer rates, seeking to understand why women of different backgrounds are more likely to develop breast cancer and what can be done to better treat them.
“If you don’t look at all of the factors, then you can never address the disparities,” Hurley said. “And disparities are an issue of social justice.”
Clues to Bahamian women’s cancer
Hurley’s studies have been part of a broader effort by researchers to target racial and ethnic disparities in breast cancer, including a major initiative in 2016 by the National Institutes of Health to study risks for black women, who have historically faced higher cancer mortality rates.
Initially, Hurley and researchers from Sylvester and the Bahamas studied hundreds of Bahamian women. They discovered the average age of breast cancer onset in these women was just 42.
Pressing further, they realized that more than a quarter of the breast cancer cases in their study were caused by mutations in two genes, BRCA1 and BRCA2, which help repair broken DNA strands when cells divide. The mutations prevent cells from being effectively fixed, leaving them vulnerable to cancer. In the U.S., these mutations account for less than 5 percent of breast cancer cases.
Later research confirmed that there are seven main potential mutations in the genes of Bahamian women that make them more susceptible to breast cancer. Genetic testing could focus on these mutations so Bahamian women can know whether they are at risk, and take preventative measures or get the most effective treatment.
The American Cancer Society advises women to start screening for breast cancer in their 40s. Hurley’s research revealed that those guidelines won’t work for Bahamian women, said Dr. Raleigh Butler, director of gynecology and women’s health at the University of West Indies in the Bahamas.
“In the Bahamas, we have changed our recommendation as a direct result of this work,” Butler said. “The new recommendation is for women who have a first-degree relative with breast cancer, you should begin having ultrasounds between 25 and 30.”
Hurley said the team has approached their work with great care, recognizing the sensitivity of handling people’s genetic and medical histories. They clearly explain genetic testing results to patients and have trained Caribbean clinicians in genetic counseling to continue the work, she said.
Expanding beyond the Bahamas
The researchers didn’t stop with the Bahamas. They also looked at women in Haiti, Trinidad and Tobago, Jamaica and other islands. Throughout the Caribbean, women develop breast cancer at up to twice the rate of U.S. women, according to the Centers for Disease Control and Prevention. One out of 8 American women develop breast cancer, but in the Bahamas that jumps to nearly 1 in 3.
“[Breast cancer] is really kind of an epidemic in the Caribbean right now,” Hurley said. “It’s the leading cause of cancer death in every island except Haiti.”
Women in the Bahamas and across the Caribbean develop breast cancer two decades before the average American woman.
While island nations have isolated gene pools — making it easier to pass on harmful mutations — inherited genetics do not account for all disparities in breast cancer rates.
Breast cancer is most prevalent in more developed countries, due, in part, to higher obesity rates, which increase the risk of breast cancer. Over the past 25 years, Caribbean nations have been industrializing and adopting more Westernized lifestyles, which may be increasing rates, Hurley said.
Where someone lives makes a difference not only in the treatment they receive but in the emergence of the breast cancer itself.
Breast cancer in Haitian-born women recently immigrated to the U.S. differs from the disease in women living in Haiti, according to a Sylvester study. In Haiti, women developed breast cancer earlier and had much worse outcomes.
Sophia George, Ph.D., works with Hurley and analyzes genetic mutations in cancer patients using breast and Fallopian tubes tissue. She also focuses her research on epigenetics, or how external factors like stress and diet impact the body’s genetic expression.
She studies the personal and medical histories of Caribbean women to further understand the impact of their environment on cancer outcomes.
“That’s really telling us about the story of that person, their lived experience, and how that will affect their outcome,” George said.
Past research has shown that black women in the U.S. are diagnosed at more advanced stages and with more aggressive forms of breast cancer than white women in the U.S. Black women have historically had their breast cancer diagnosed later than white women, accounting for the higher mortality rates. Lack of healthcare access for many blacks has contributed to the disproportionate death toll.
Disparities within disparities
Black women aren’t all the same and there are additional disparities within this demographic that need to be broken down, George said. Black women come from a variety of ethnic backgrounds, each with particular genetic predispositions and cultural backgrounds that influence their cancer and require further analysis.
Through their work, for instance, George and Hurley have learned that black Caribbean immigrants living in the Miami area are more likely to survive breast cancer than U.S.-born black women. They are still searching for answers about why this happens.
George and Hurley plan to study breast cancer in other immigrant populations in the U.S. and Africa to gain more insight into cancer development in women of African descent.
This is far from the only instance of disparity in outcomes that has raised important questions for medical researchers. Another Sylvester study found Hispanic ethnicity to be one of the main factors in breast cancer survival in South Florida women — contrary to the mixed results from national studies.
The reason for the higher survival rate remains unclear, said Dr. Neha Goel, who conducted the soon-to-be published study of breast cancer in South Florida women. But understanding why South Florida Hispanic women fare better against cancer can help improve their treatment and that of women in other demographics, she said.
“The goal is to develop targeted interventions to eliminate breast cancer disparities in South Florida,” Goel said.
If you go
The 24th annual Susan G. Komen MORE THAN PINK walk in Miami-Fort Lauderdale will take place from 6:30 a.m. to 12 p.m. Saturday at Bayfront Park, 301 Biscayne Blvd. The walk aims to raise money for breast cancer treatment, research and advocacy.
Registration begins at 6:30 a.m., the Procession of Hope begins at 8:15 a.m., and the walk starts at 8:45 a.m.