An aggressive form of breast cancer that is killing mostly black women is in the crosshairs of a young Barbadian scientist who is determined to fight it.
Shawn Hercules told Barbados TODAY that women affected by Triple Negative Breast Cancer (TNBC), have no targeted therapies currently to ensure their survival.
In these circumstances, women with TNBC are likely to have the cancer spread beyond the breast tissue and after treatment it is likely to recur.
“TNBC means the tumour doesn’t have oestrogen receptor, progesterone receptor or human epidermal growth factor receptor 2 (ER, PR, Her2). The tumour is not positive for these receptors and is therefore deemed triple negative. Some tumours that are ER positive or Her2 positive can be treated with targeted therapies. TNBC lacks those receptors and have no targeted therapies, which drives its aggressiveness,” he explained.
Hercules said his goal was to investigate the epidemiological and genetic signatures of TNBC in women of African descent and hopefully identify a genetic profile that these women can be tested for this type of cancer.
With a background steep in science, in 2012 Hercules completed a Bachelor of Science degree in Biochemistry and Chemistry and later a Master of Science degree in Public Health. And to further strengthen his research skills he spent time at the Chronic Disease Research Centre (CDRC).
However, it was a trip to the earthquake ravaged Haiti in 2010 that truly ignited his desire to pursue the area of public health and changed his career plan.
“I was moved to understand the disparities that I observed and a subsequent trip in 2013 solidified this and drew me to apply for and pursue a Master’s in Public Health at Cave Hill Campus,” he recalled.
“At that time, I was very interested in chronic diseases and CRDC bases its research on chronic diseases in the Caribbean. I was part of the National Institutes of Health in America project which conducted systematic reviews and we published two reviews under the supervision of Professor Ian Hambleton, Dr. Natasha Sobers-Grannum and Dr. Madhuvanti Murphy,” he said.
Currently pursuing PhD in Biology at McMaster University in Canada, the Barbadian has zeroed in on breast cancer due to the racial disparity observed in breast cancer rates and mortality.
“In the United States and the United Kingdom, breast cancer incidence has been higher in white women, whereas breast cancer mortality has been higher in black women,” he pointed out.
Hercules said some studies show that socio-economic factors may be contributing to this striking difference between cancer death rates among whites when compared to black women, while others believe there is a biological component driving these trends.
“Despite the fact that the overall incidence is higher in white women, there is a higher prevalence of a very aggressive form of breast cancer called triple negative breast cancer (TNBC) in black women.
“This subset of breast cancer typically leads to higher mortality and recurrence rates,” he said, noting there was no targeted therapeutic agents for TNBC which is also driving the fatality rates for the cancer.
“My research seeks to answer this racial disparity observed in TNBC. I want to know what are the genetic and epidemiological risk factors for TNBC in women of African ancestry. So currently, we have collaborators (hospitals and health centres, pathologists, oncologists and cancer societies) in Nigeria, Ghana, Barbados, hopefully Jamaica soon and here in Toronto to help us identify patients and locate tissue samples. We are hoping to also invite collaborators from other Caribbean islands,” Hercules told Barbados TODAY.
Nigeria and Ghana, two of the participating countries were specifically chosen. He explained: “We are investigating the route from the transatlantic slave trade. We believe that there is a unique genetic signature observed from West Africa (Nigeria and Ghana) across the Caribbean and into North America that is predisposing black women to aggressive TNBC.
“I am collecting breast cancer tissues from women in these cohorts, clinical information from pathology, patient notes and I’m interviewing women in the study about their lifestyle habits.
“One of our most recent publications with tissues from Barbados and Nigeria showed that Kaiso which is a protein that is implicated in various cancers (breast, prostate, lung, colorectal) and its expression is often linked to the overall aggressiveness of the cancer and there was more Kaiso present in TNBC tissues of Nigerian women, linking it African ancestry.
“Kaiso was more highly expressed in Nigerian tissues than Bajan TNBC tissues compared with African American and Caucasian American TNBC tissues. This was an interesting finding since it suggests that Kaiso may have a role in the racial disparity observed in TNBC,” the Barbadian scientist and cancer researcher disclosed.
He explained the protein was identified and named Kaiso by Dr Juliet Daniel some 20 years ago (as an ode to the kaiso music that kept her up late at night in the lab).
“Being in Dr Daniel’s lab is like a dream come true for me as after my trip to Haiti, I said I wanted to travel to underdeveloped countries to undertake life changing health research and I went to Nigeria for my project and I probably will be back sometime soon to make a difference in this aspect of cancer,” he said.
According to Hercules, Dr Daniel started this cancer research in 2011 with teams in Barbados.
“More work is being done to explore other proteins that also drive cancer’s aggressiveness, but we need more tissues to fully understand the biological relevance of what we’re seeing.
“We also found that Nigerian and Bajan women in our study were diagnosed with TNBC at a younger age than African American and Caucasian American women.
“For my study, I will be looking for mutations in DNA of these tissues to see if there is a common genetic signature across these women of African ancestry in the study which may be linked to TNBC similarly to what is observed for BRCA1 (protein) mutations in women of Jewish ancestry. Additionally, novel mutations can help us identify targeted therapies for TNBC,” said Hercules.
Noting that the work could not be done without the help of health institutions, he thanks local health teams for their assistance.
“The doctors at the Queen Elizabeth Hospital have been extremely helpful, particularly Dr Desiree Skeete a pathologist at the Department of Pathology and Dr Suzanne Smith Connell from the Department of Radiation Oncology who helped us collect the tissues and get women with TNBC enrolled in the study,” he said.
Hercules said he was equally pleased with the work being done in Barbados to raise awareness about breast cancer.
“I was happy to see the turn out at the CIBC Walk for the Cure event and I hope that Bajan women take heart to really know their bodies and if there are any abnormalities, go to the doctor and get it checked out as soon as possible. We don’t have much of an excuse when healthcare is provided for by the Government,” he insisted.
In five years, the medical trailblazer sees himself making a difference in the fight against cancer.
“Whether it’s by training and mentoring younger scientists from under-represented groups to embark on these types of projects or by being employed by a larger organization that can send me and others to do this type of work – I’m not sure but I’d be happy with either right now,” said Hercules who is hoping to be finished his PhD by 2020 the latest.
The former Combermere student said when he was younger he just wanted to be a doctor, but it was that trip to Haiti in 2010 that completely altered his ambition and it was a decision with which he has no regrets.
“I have to thank the folks at CDRC, Healthy Caribbean Coalition and UWI for laying a solid public health foundation for me to work on my project. My People’s Cathedral church family back home for their prayers and support. My brother, who is a research assistant on the project, for collecting clinical information as well as tissue specimens. My supervisor Dr Juliet Daniel for taking me into her lab and my family for always being supportive and helping me to get where I am today,” said Hercules.