Exploring the genetic landscape of breast cancer in Ghana

Lily Paemka is a lecturer at the department of Biochemistry, Cell and Molecular Biology at the University of Ghana. She is also a DELTAS Africa Postdoctoral Fellow at WACCBIP. WACCBIP (West African Centre for Cell Biology of Infectious Pathogens) is one of the eleven Developing Excellence, Leadership, and Training in Science in Africa (DELTAS Africa) programmes. DELTAS Africa funds Africa-based scientists to amplify the development of world-class research and scientific leadership on the continent while strengthening African institutions. DELTAS Africa is implemented through the AESA Platform. AESA (The Alliance for Accelerating Excellence in Science in Africa) is a funding, agenda-setting, programme management initiative of the African Academy of Sciences (AAS), the African Union Development Agency (AUDA-NEPAD), founding and funding global partners, and through a resolution of the summit of African Union Heads of Governments. DELTAS Africa is supported by Wellcome and the United Kingdom Foreign, Commonwealth and Development Office (FCDO formerly DFID).

Summary

Breast cancer is the most common cancer in women both in the developed and less developed world. This study explores why breast cancer manifests aggressively in black women and provides a comprehensive genetic landscape to develop resources that could lead to novel molecular therapies.

A genetics affair

As cliché as it sounds, I experienced a “Eureka!” moment the first time I was introduced to the Human Genome Project as an undergraduate at the University of Ghana. That moment crystalized my life goals and steered my foray into human genetics. I went on to train as a human molecular geneticist at the University of Iowa and studied complex and Mendelian human genetic diseases as a doctoral student and a postdoc. I characterized genes involved in autism spectrum disorders, epilepsy and cystic fibrosis. I’m primarily interested in human genetic traits, particularly in describing genetic variations and elucidating pathways in genetic diseases. While planning to return to Ghana three years ago, I was struck by the dearth of research data on genetic diseases in that country, in particular breast cancer. Considering that breast cancer is a global public health challenge, I was motivated to focus my efforts on the disease. Before returning to Africa, I went on to train as a postdoc in a cancer lab at the University of Iowa. I subsequently won a WACCBIP DELTAS Africa Postdoctoral fellowship (2017-2020) to characterize breast cancer genetic risk factors in Ghanaian women. This fellowship has been instrumental in bringing me back to Ghana, setting up my laboratory, building an invaluable biospecimen collection and generating preliminary results.

Breast cancer: a black crisis

The burden of cancer in Africa is a growing public health challenge. Breast cancer in the indigenous black population presents with an aggressive biology and is associated with a disproportionately high mortality rate in Africa. Worldwide, 2.1 million women are affected annually; in 2018, 627,000 of them succumbed to the disease. Over 19.3 million women are estimated to suffer from the disease by 2025, with the majority from Africa. In Ghana, breast cancer mortality is as high as 50%, accounts for 16% of all cancer cases, and is responsible for the majority of cancer-related deaths in women. The aggressive triple negative breast cancer (TNBC) sub-type is overrepresented in people of West-African ancestry and accounts for a disproportionate number of metastatic cases and deaths. Largely Eurocentric studies are not particularly representative of our population due to racial and ethnic differences in breast cancer pathology. The goal is to provide a more comprehensive genetic landscape of breast cancer in black women and develop resources that could lead to novel molecular therapies. Breast cancer is a global problem and studying the genetically diverse Ghanaian population will provide valuable resources in the global fight against breast cancer.

Finding a Ghanaian solution

Unique breast cancer characteristics in black women suggest peculiar genetic changes associated with African ancestry. Breast cancer develops from complex genetic modifications in breast cells and is known to have a complex cause involving genetic and environmental factors that include bacteria and viruses. As these risk factors are unknown in Ghanaian women, my lab is involved in identifying inherited and sporadic genetic changes that predispose Ghanaian women to breast cancer and pathogens (bacteria and viruses) associated with the disease in the population. Breast tumour samples from consenting women were subjected to methodologies including Next-Generation Sequencing and pathway analyses. Preliminary results show interesting genetic variations and the presence of oncogenic viruses. Also, breast microbiome analyses have revealed some fascinating signatures associated with breast cancer in Ghanaian women. Ultimately providing data relevant to the African population ensures that relevant findings will have clinical impact by way of genetic counselling and treatment modalities in our population.

Also, to mitigate the high rates of late presentation of breast cancer in Ghanaian women, my lab, with support from the WACCBIP Communications and Public Engagement team, has established and spearheaded the Nufu FestivalÒ to engage the public, raise breast cancer awareness, and provide free breast examinations. We have reached close to 2,000 women within two years, and our free breast examinations have helped identify several cases of possible early breast cancer manifestation. With the firm belief that public engagement can make a world of difference in the prevention of complications relating to late presentation of breast cancer, we have focused our efforts on reaching larger groups of women and men with targeted messages intended to encourage regular self-examination. We do this through dedicated conversations on popular radio and TV talk shows in Ghana, on which we also actively address myths traditionally associated with the disease.

A luta continua

We aim to continue our work in elucidating genetic variations and pathogenic risk factors associated with breast cancer in African women. I was recently fortunate to win the 2021 Organization for Women in Science for the Developing World (OWSD) Fellowship to support my research efforts, which will provide funding support for the next two years. We hope to reach more women with our message of breast health and to expand the Nufu FestivalÒ to become a national event attracting hundreds of thousands of women and placing the conversation on breast cancer firmly on the national agenda.