World Cancer Day: Prevention and Care for Everyone

This World Cancer Day, let’s commit to closing the cancer care gap and ensuring that everyone, no matter where they live, has a fair chance at prevention, early detection, and effective treatment.

Here we take a closer look at the global landscape of cancer, the disparities between high- and low-income countries, and the critical role of prevention and early detection.

The Global Burden of Cancer: A Growing Challenge

Cancer continues to rise globally, becoming one of the leading causes of death. In 2022, an estimated 20 million new cases and 10 million deaths were reported, according to the International Agency for Research on Cancer (IARC). The numbers continue to rise due to aging populations, environmental exposures, and lifestyle factors. Alarmingly, recent data suggest a rise in cancer cases among young adults, particularly colorectal and breast cancer, pointing to the potential influence of diet, obesity, sedentary lifestyles, and environmental exposures. However, the impact of cancer is not distributed evenly across the globe.

Cancer Disparities Across the World

Cancer incidence and survival rates vary significantly depending on where you live. High-income countries (HICs) tend to have a higher cancer burden due to longer life expectancy and more comprehensive screening programs. However, survival rates are also higher because of better healthcare infrastructure, early detection, and advanced treatments. In contrast, low- and middle-income countries (LMICs) face a growing cancer crisis, with significantly lower survival rates due to late diagnoses and limited access to care.

Source: IARC.

A striking example is breast cancer: in North America and Western Europe, five-year survival rates exceed 85%, whereas in sub-Saharan Africa, they can be as low as 40% due to delayed diagnosis and lack of treatment facilities.

Cancer incidence is deeply shaped by social inequities also within countries, with major cancers such as lung, stomach, and cervical cancer disproportionately affecting socioeconomically disadvantaged populations due to differences in exposure to risk factors, healthcare access, and preventive measures. While disparities in diagnosis and treatment are well-documented globally, evidence from countries with universal public healthcare systems, such as Spain, suggests that treatment-related inequities may be smaller, although differences in early detection and quality of care can still persist.

The Role of Infections in Cancer: A Disproportionate Burden

While lifestyle factors such as smoking, diet, and physical inactivity play a major role in cancer risk worldwide, infections are a key driver of cancer in LMICs. Up to 25% of cancer cases in low-income settings are linked to infections, compared to less than 10% in high-income countries.

Some of the most common infection-related cancers include:

• Cervical cancer, caused by the human papillomavirus (HPV), remains a leading cause of death among women in many low-income countries due to limited access to screening, HPV vaccination and adequate treatment.
• Liver cancer, linked to hepatitis B and C infections, is more prevalent in parts of Africa and Asia where vaccination and antiviral treatments are less widespread.
• Stomach cancer, associated with Helicobacter pylori infection, disproportionately affects populations with poor sanitation and healthcare access.

Expanding vaccination programs, such as the HPV vaccine for cervical cancer and hepatitis B vaccine for liver cancer, could prevent hundreds of thousands of cases each year.

Climate Change and Cancer: An Emerging Threat

Climate change is increasingly recognized as a factor influencing cancer risk and outcomes. Rising temperatures, air pollution, and extreme weather events contribute to increased exposure to carcinogens and disrupt healthcare services. Strengthening environmental policies, reducing emissions, and ensuring resilient healthcare systems will be key in mitigating these impacts.

Prevention: The Most Powerful Tool Against Cancer

While cancer is a complex disease with multiple causes, up to 50% of cases could be prevented through lifestyle changes and public health policies addressing tobacco control, air pollution (both outdoor and indoor), healthy diet and physical activity, alcohol consumption, sun protection, and occupational safety. Recent research continues to uncover new risk factors for cancer. Ultra-processed foods, rich in additives, emulsifiers, and artificial sweeteners, have been linked to an increased risk of colorectal and other cancers. Microplastics, now found in human tissues, raise concerns about their long-term health effects, including potential carcinogenic properties. Additionally, disruptions to circadian rhythms, such as night shift work and chronic sleep deprivation, have been associated with higher risks of breast and prostate cancer. As scientific knowledge advances, addressing these emerging risks through policy changes, lifestyle interventions, and further research will be key to cancer prevention.

Cancer in Spain: Current Challenges and Advances

Spain, like many high-income countries, faces a significant cancer burden. According to recent estimates, more than 280,000 new cancer cases were diagnosed in Spain in 2023. The most common cancers include colorectal, breast, lung, and prostate cancer.

Key trends and challenges in Spain include:

• An aging population, which is increasing cancer incidence, particularly for age-related cancers such as prostate and colorectal cancer.
• Lung cancer remains a major issue, particularly among women, as smoking rates have historically been high.
• Obesity and lifestyle factors, including diet and physical inactivity, are contributing to rising cases of certain cancers.
• Environmental exposures, including air pollution, water pollution, radiation and occupational risks, play a role in cancer incidence.

Spain has made significant strides in early detection and treatment, with widespread screening programs for breast, colorectal, and cervical cancer. However, disparities remain in access to advanced therapies and care, particularly between different regions.

This World Cancer Day, let’s commit to closing the cancer care gap and ensuring that everyone, no matter where they live, has a fair chance at prevention, early detection, and effective treatment.

Work on Cancer by ISGlobal researchers

Environmental, Occupational, and Radiation Exposures:

• Non-ionizing radiation, including extremely low frequency and radio frequency exposures (e.g., mobile communication, occupational settings).
• Ionizing radiation from occupational and medical sources (CT scans, cardiology, radiotherapy).
• Ongoing development of a childhood cancer survival cohort in Spain, 
• Air pollution, environmental, occupational, and climate-related exposures, including global cancer burden assessments.
• Chemicals in drinking water and swimming pools.
• Endocrine disruption, anogenital distance, and prostate cancer.

Circadian Rhythms and Nutrition:

• Shift work, circadian rhythms, sleep, and cancer chronotherapy.
• Nutrition and nutrition patterns -omics, including links between nutrition and circadian regulation (chrononutrition)
• Exposome-genetics interactions in circadian disruption.

Cancer Prevention, Screening, and Survival:

• HPV screening strategies for low-resource settings, applying AI and imaging applications for cervical cancer.
• Urban health and habitat-related factors in breast and prostate cancer survival.

Molecular, Genetic, and Biomarker Research:

• Bioinformatics and genomics in cancer research.
• Molecular characterization and biomarkers of disease progression in human papillomavirus (HPV)-related cancers.
• Immunology in exposome studies using high-throughput serology technologies.

Evidence Synthesis and Methodological Expertise:

• Evidence synthesis across climate, environmental, and occupational exposures