Unraveling the Mystery: Cancer in Populations of African Ancestry

Exploring the unequal cancer burden and the groundbreaking research by the African Caribbean Cancer Consortium

Health Disparities Cancer Research African Ancestry

The Unequal Burden of Cancer

Imagine two neighborhoods, side by side, where residents of one community consistently face more aggressive forms of cancer, are diagnosed at later stages, and have fewer survival opportunities. This isn't merely a hypothetical scenario—it's the reality for millions of people of African ancestry around the world. While cancer touches lives in every community, its impact falls disproportionately on people of African descent across the United States, the Caribbean, and Africa 6 .

4x Higher

Cervical cancer rates in Caribbean women compared to U.S. women 1

Highest Rates

Prostate cancer incidence in the Caribbean globally 1

Elevated Mortality

Cancer mortality rates in African ancestry populations worldwide 6

For decades, these alarming disparities persisted without receiving the scientific attention they warranted. Then, in 2006, a dedicated group of researchers decided to confront this challenge head-on by forming the African Caribbean Cancer Consortium (AC3) 3 .

Understanding the Disparity: The Mission of the AC3

The African Caribbean Cancer Consortium emerged from a simple but powerful recognition: cancer in populations of African ancestry had been chronically understudied, leaving critical gaps in our understanding of how and why cancer develops differently across populations. Founded by Dr. Camille Ragin and now comprising researchers from the United States, Africa, and the Caribbean, the AC3 has built a multidisciplinary approach to address this complex challenge 3 .

Genetic Factors

African-ancestry-associated variants and differences in tumor mutational profiles 2

Viral Factors

Higher prevalence of cancer-associated viruses in Caribbean populations 1

Healthcare Systems

Limited screening access and underdeveloped cancer registries 6

Social & Economic

Lower socioeconomic status and cultural barriers to care 6

Cancer Registry Development in the Caribbean

Country Type of Registry Year Established Estimated Population (2007)
Cuba National Cancer Registry 1964 11,416,987
Jamaica Urban Cancer Registry 1959 2,780,132
Martinique National Cancer Registry 1983 439,202
Trinidad and Tobago National Cancer Registry 1994 1,056,608
Bahamas National Cancer Registry Unknown 305,655

The Viral Connection: Uncovering Infectious Links to Cancer

One of the AC3's key research areas explores the role of viruses and other infectious agents in driving the high rates of certain cancers in Caribbean populations. Early in their work, AC3 researchers noted a striking pattern: several cancers that occur more frequently in the Caribbean compared to the United States have known links to infectious agents 1 .

Cervical Cancer Rates Comparison

Caribbean women experience cervical cancer rates more than four times higher than women in the United States 1

HPV-Associated Cancers

High frequency of HPV infection among Jamaican women corresponds with high cervical cancer rates 1

Research Impact

Understanding which HPV types are most common in Caribbean populations helps determine how effective current HPV vaccines will be in these regions. Similarly, confirming viral links to cancers opens possibilities for prevention through vaccination and targeted screening in high-risk populations.

Decoding the Genetic Blueprint: Ancestry-Associated Genomic Differences

While social and healthcare factors explain part of the cancer disparity story, AC3 researchers recognized that biological differences also play a crucial role. Until recently, however, cancer genomics research has predominantly focused on populations of European ancestry, creating critical knowledge gaps about how cancer develops and progresses in people of African descent 2 .

Targetable Mutations by Ancestry

Recent research revealed depletions for targetable driver mutations in tumors from patients with African ancestry 2

Key Genomic Findings

Genomic Feature Finding in African Ancestry Populations
Targetable Mutations Depletions in KRAS G12C and EGFR L858R mutations 2
Tumor Mutational Burden Significant differences compared to other ancestries 2
Triple-Negative Breast Cancer Higher prevalence in women with African ancestry 2
Prostate Cancer Risk Association with short Androgen Receptor alleles 1

Clinical Implications

These genetic findings help explain why triple-negative breast cancer (TNBC)—a more aggressive subtype that is harder to treat—is more prevalent in women with African ancestry. The higher frequency of this aggressive breast cancer subtype contributes to the disproportionate mortality experienced by Black women with breast cancer, even when diagnosed at similar stages as women of other racial backgrounds 2 6 .

A Closer Look at a Key Experiment: The Kaiso Biomarker Study

To understand how AC3 researchers are uncovering the biological underpinnings of cancer disparities, let's examine a pivotal study on triple-negative breast cancer (TNBC) that compared breast cancer tissues from Caucasian, African American, Caribbean, and African women 6 8 .

Methodology: A Step-by-Step Approach

Sample Collection

The research team gathered breast cancer tissue samples from multiple sources, ensuring representation across the African diaspora: Caucasian women (primarily from the U.S.), African American women (from the U.S.), Caribbean women (specifically from Caribbean nations), and African women (from specific African nations) 6 8 .

Biomarker Selection

Previous research had identified a protein called Kaiso as potentially correlated with aggressiveness in triple-negative breast cancer. Kaiso is a transcription factor that can regulate how genes are expressed, potentially influencing cancer behavior 6 8 .

Tissue Analysis

Using specialized laboratory techniques, the researchers measured and compared Kaiso expression levels in the different groups of breast cancer tissues. This allowed them to determine whether Kaiso was present at higher or lower levels in tumors from women of different ancestries 6 8 .

Statistical Comparison

The team then statistically analyzed the differences in Kaiso expression across the various population groups, controlling for other factors that might influence the results 6 8 .

Results and Analysis: What They Discovered

Kaiso Expression in Breast Cancer Tissues

Significantly higher expression of Kaiso in breast cancer tissues from women of African descent compared to Caucasian women 6 8

Research Significance

The elevated Kaiso expression in tumors from women of African descent provides an important clue to understanding why triple-negative breast cancer is more common and often more aggressive in these populations. Since Kaiso is associated with cancer aggressiveness, higher levels of this protein might contribute to the more aggressive disease course observed in women of African ancestry.

This experiment exemplifies the power of comparative studies across different populations of African descent. By examining samples from Africa, the Caribbean, and the United States, researchers could distinguish patterns consistent across the African diaspora from those unique to specific geographic regions. This approach helps separate the influences of genetics from environmental and lifestyle factors, providing a more complete picture of what drives cancer disparities.

Beyond the Laboratory: The Path Forward

The work of the African Caribbean Cancer Consortium represents more than just scientific discovery—it's a comprehensive effort to transform cancer outcomes for populations of African ancestry. Their research has already yielded practical applications, from informing HPV vaccination strategies in the Caribbean to revealing why certain targeted therapies may be less effective for patients of African descent 1 2 .

The LIFE Project

The LIFE Project (Living In Full HEalth) is an island-wide cohort study in Jamaica that will enroll 8,000 participants to understand the roles of genetics, social, environmental, and lifestyle factors in cancer, cardiovascular disease, and diabetes 9 .

IRONMAN Registry

The International Registry for Men with Advanced Prostate Cancer (IRONMAN) now includes several Caribbean and African countries, creating the first large-scale database on advanced prostate cancer in these populations 9 .

Recognition

The consortium's efforts have not gone unnoticed—in 2023, the AC3 received the American Association for Cancer Research Team Science Award, recognizing their innovative collaborative approach to addressing cancer disparities 5 .

Comprehensive Approach

Perhaps the most important lesson from the AC3's work is that addressing cancer disparities requires a multifaceted approach that includes everything from fundamental genetic research to community education, from improving cancer registries to advocating for better access to screening and treatment. As their research continues to reveal, the solutions to cancer disparities in populations of African ancestry will be found not only in sophisticated laboratories but also in strengthened health systems, engaged communities, and international collaborations dedicated to health equity.

As Dr. Camille Ragin and her colleagues continue to build this scientific bridge across the African diaspora, their work offers hope that the disturbing patterns of cancer in populations of African ancestry can be changed—and that the insights gained may ultimately contribute to better cancer care for all people, regardless of their ancestry.

References