The Exposome: A New Framework for Understanding Global Cancer Disparities
Cancer risk is determined by a lifetime of environmental, social, and biological exposures—collectively known as the “exposome”—rather than genetics alone, according to a new book chapter by Kamal Saini and colleagues. Published in “The Exposome in Cancer Disparities,” the research argues that air pollution, infectious diseases, and socioeconomic conditions create cumulative risks that disproportionately affect low- and middle-income countries (LMICs). Addressing these disparities requires a shift toward integrated public health policies that account for the lifelong interaction between environment and human biology.
Why Do Environmental Exposures Drive Cancer Risk?
Environmental factors remain a primary driver of cancer incidence, particularly in regions with rapid industrialization. According to the research team led by Kamal Saini, the Global Head of Oncology Therapeutic Expertise at Fortrea, air pollution, hazardous chemical exposure, and the widespread use of pesticides are significant contributors to the global cancer burden. Unlike genetic predispositions, these environmental factors are often modifiable through policy and infrastructure improvements. The authors note that as urbanization continues, these risks are becoming increasingly concentrated in vulnerable populations, widening the health equity gap between high-income and low-income nations.
The “exposome” encompasses every exposure a person experiences from conception to death, including diet, physical activity, and social stressors, acting as a crucial counterpart to the human genome.
How Do Infectious Diseases Influence Cancer Outcomes?
Infectious agents are a leading, yet preventable, cause of cancer in many LMICs. Kamal Saini and his co-authors, including Professor Zodwa Dlamini, identify viruses such as Human Papillomavirus (HPV), Hepatitis B and C, Epstein-Barr Virus (EBV), and HIV as major drivers of cancer mortality in these regions. These infections often intersect with poor healthcare access, meaning that cancers which are treatable in high-income settings frequently progress to advanced stages in LMICs. The research emphasizes that expanding vaccination programs and early screening initiatives is essential to lowering these specific, high-burden cancer rates.
What Role Do Social Determinants Play?
Social conditions serve as an “amplifier” for cancer risk, according to the findings published by Academic Press. Poverty, limited access to medical facilities, poor nutritional standards, and high rates of tobacco and alcohol consumption create a cycle of vulnerability. The authors argue that these social determinants are not merely background factors but are active participants in biological disease progression. By treating social and economic realities as part of the cancer risk profile, public health officials can better design interventions that target the root causes of health inequities.
How Can We Reduce Global Cancer Disparities?
Closing the gap in cancer outcomes requires a shift from isolated risk assessment to a holistic, evidence-based approach. The researchers outline five priorities for global health systems:
- Strengthening primary prevention strategies.
- Implementing earlier detection and screening programs.
- Investing in robust healthcare infrastructure.
- Enacting evidence-based policy reforms.
- Fostering global collaboration across research and public health sectors.
When reviewing patient risk, clinicians are increasingly encouraged to look beyond family history and consider the patient’s geographic and socioeconomic environment to identify potential environmental triggers.
Frequently Asked Questions
What is the exposome in the context of cancer?
The exposome represents the total sum of environmental exposures an individual experiences throughout their life, including pollution, diet, infections, and social conditions, which interact with genetics to influence cancer risk.
Why are cancer outcomes worse in low- and middle-income countries?
Outcomes are often worse due to a combination of higher exposure to infectious agents, limited access to early screening and detection, and social determinants like poverty and poor healthcare infrastructure, according to the research by Kamal Saini.
Is cancer mostly genetic?
No. While genetics play a role, the research highlights that a significant portion of cancer occurrence is driven by the cumulative impact of environmental and social exposures that occur over a lifetime.
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