A study from seven Caribbean countries found that an average of one in seven Caribbean-born people on the islands diagnosed with breast or ovarian cancer carries at least one inherited gene mutation.
Of the seven areas – Jamaica, Trinidad and Tobago, Cayman, Bahamas, Barbados, Dominica, and Haiti – Cayman had the second lowest rate of hereditary breast and ovarian cancer at 6.3%, after Jamaica at 4.9%. The Bahamas had the highest share with 23%, Barbados with 18%, Trinidad and Tobago with 12%, Dominica with 8.8% and Haiti with 6.7%.
The oncologist Dr. Judith Hurley, a researcher at the Sylvester Comprehensive Cancer Center at the University of Miami’s Miller School of Medicine, has been studying racial differences in breast cancer rates since 2002. She was asked to do the study after noting so many of her Bahamian breast cancer patients were unusually young. You and your colleague Dr. Sophia George teamed up with fellow colleagues from Sylvester, the University of Toronto, and the Bahamas to find out why.
Dr. Judith Hurley
They found that more than a quarter of the women studied had mutations in two genes, BRCA1 and BRCA2. In comparison, these mutations account for less than 5% of US breast cancer cases. They also found that the median age for breast cancer in Bahamian women was 42 years – about 20 years younger than American women.
The team’s research was then expanded to six other English- and Creole-speaking Caribbean islands, including Cayman.
Their findings, entitled “Gene Sequencing for Pathogenic Mutations in Adults with Breast and Ovarian Cancer in the Caribbean,” were published March 1 in the JAMA Network Open Medical Journal. It is the largest cross-sectional study of its kind.
They hope the results of the study will lead to better screening and treatment for cancer patients in the Caribbean in their home countries and in South Florida. Breast cancer is the leading killer of women in the Caribbean, while ovarian cancer ranks fourth.
The mean age of the patients with BRCA mutations was 40.7 years, younger than the 47.5 years without the mutation.
Speaking to the Cayman Compass, Hurley and George said the research team found different mutations between each island in the study.
“We found it was different from island to island,” said George. “Every country had its own spectrum of mutations. Each country had its own genetic fingerprint. “
The team first came to Cayman in 2012 to perform genetic testing on 62 women who had either recovered from or suffered from breast or ovarian cancer. A second round of advanced testing was done later when advancing technology made it possible to study more gene sequencing.
In Cayman, Hurley and George tested women who had at least one Cayman grandparent for the purpose of the study. “6.3% were found to have one of the breast cancer genes that is in the range of the US or European numbers. It’s a lot lower than other Caribbean countries, ”said George.
The gene mutations found in Cayman were BRCA1 and BRCA2, the scientists said.
Hurley said that people diagnosed with either of these mutations had a 65-80% chance of developing breast cancer and up to a 40% chance of developing ovarian cancer by the age of 70.
Dr. Sophia George
She and George advise anyone with a family history of breast or ovarian cancer to consider getting gene screening so they can take action to reduce the risk.
In total, the Sylvester researchers tested 1,018 adults with breast or ovarian cancer.
Initially, the researchers only looked for the BRCA1, BRCA2, PALB2, and RAD51 mutations. However, towards the end of the study, study participants underwent full next-generation sequencing on a panel of 30 as multi-gene panel testing became cheaper and more available genes.
In the Bahamas, the work of researchers has already changed the guidelines for breast cancer screening. The American Cancer Society recommends starting screening when women are over 40 years old. However, Bahamian women with a first-degree breast cancer relative are recommended to start ultrasound in their mid-20s.
Unlike the UK, where women over 50 are invited to have a mammogram every three years, Cayman has routine mammography screenings every two years from the age of 40 or as recommended by a doctor.
Dr. Sook Yin, medical director of the Cayman Islands Cancer Society who was in contact with the study’s authors through the Cayman portion of the research, said back in 2012, when the tests were first run, that some Caymanian patients were unwilling to this to take part.
This was due to two factors, she said – the perceived stigma of having cancer in the family and concerns that their health insurance company would penalize them if a test found they had an inherited gene that they identified for breast or breast cancer Ovarian Cancer Predisposed Companies.
“They feared that they could face higher premiums or be excluded from insurance,” said Yin.
While genetic sequencing tests are not currently done on the island, they are readily available in the US and swab samples can be mailed to anyone who wishes to take them. Yin said she had a number of patients who had done these type of genetic tests and found that they inherited genes that made them susceptible to certain types of cancer.
“Now that genetic testing is so easily available, people can request it from their doctor and just send it off,” she said. As a result, she had a few patients with BRCA genes and close relatives with breast cancer who chose to have a double mastectomy because they knew their risk of cancer was so high.
Actress Angelina Jolie was known to undergo a double preventive mastectomy in 2013 after a test showed she had the BRCA1 gene. Her mother had battled cancer for a decade and died at the age of 56. Jolie said her doctors have an 87% risk of developing breast cancer and a 50% risk of developing ovarian cancer.
Other factors involved
Hurley said while research found that 25% of the cancer patients in the Bahamas study had the mutated genes, it meant that it was not yet known why the other 75% developed breast or ovarian cancer. “The women who had the mutation developed cancer an average of 33 to 35 years old. for the other women with no mutation it was 48. That’s really young. There is much more to this story.
“Now that genetic sequencing is so cheap, it can be commercially available and viable in Caribbean islands. Once you know you have one of these genes, you can reduce your risk, and that is a very powerful thing – being able to take control of your life and develop risk reduction strategies. “
Hurley said over 90% of women tested in the Caribbean Islands had found their own breast cancer through self-tests or because their doctor found a lump rather than through routine mammography screening. The majority of the women in the study were also stage 3 or 4 at diagnosis, she said.
“Maybe we need to work on a different way women become aware of their own breasts,” Hurley said. “Instead of finding a mass the size of a grapefruit, which happens, maybe if it’s the size of a grape, they might find it. Maybe instead of a monthly breast check, there is a checkup that you can do every day while you put your bra on – look in the mirror, check your breasts daily to see if anything has changed from the day before – something that takes less than 10 seconds. “
Janette Fitzgerald, director of the Breast Cancer Foundation, said the charity is seeing many more women under 40 with breast cancer than expected.
To help with early detection and timely treatment, she said, “We can only target women of all ages. We go to schools and talk to the 14+ age group. Our awareness program emphasizes that all age groups are at risk. “
Dr. Ginny Hobday, the medical director of the Breast Cancer Foundation, said the Hurley / George study highlighted that geography plays a role in cancer risk factors, and the study’s results could be used to identify and guide previous diagnoses and groups at risk Treatments, especially for younger women.
The exact prevalence of breast or ovarian cancer in Cayman is unknown as the only island-wide record of cases is kept in the cancer registry. However, it is not mandatory for medical professionals to register every case.
“Since we don’t have a mandatory cancer registry, it’s all anecdotal,” Hobday said. “It’s been a problem for a long, long time.”
According to the Cancer Society, most local insurance plans include at least $ 200 in wellness benefits that can be used for the cost of mammography screening, and they urge women to take advantage of these benefits.
Having recently published their results, Hurley and George are now investigating the study group’s “epigenetic factors”. Hurley explained, “Inherited mutations called germline mutations are hundreds or even thousands of years old. However, the epigenetic changes can be observed in days, weeks, or months. This interaction between the DNA you inherited from your parents and the epigenetic changes in your DNA caused by fertility factors, environmental factors, your diet, and your lifestyle is fascinating. “
Age of Breast Cancer Diagnosis in Cayman
Total number of cases: 245
Source: Breast Cancer Foundation
Percentage of cancer patients with breast or ovarian cancer genes
Trinidad and Tobago: 12%
Source: Hurley and George Gene Sequencing Study
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