A recent significant study has identified that eleven types of cancer are experiencing an increase in individuals aged 20 to 49. The specific cancers on the rise include bowel, breast, ovarian, liver, kidney, gallbladder, pancreatic, thyroid, multiple myeloma, endometrial, and oral cancers. Researchers have noted that with the exception of oral cancer, all these cancers are associated with obesity, likely due to higher levels of insulin and inflammation.
Professor Montse Garcia-Closas, from the Institute of Cancer Research, London, emphasized the urgency for further research and immediate action. Addressing obesity, especially among children and young people, through enhanced public health policies and increased access to effective interventions, is crucial to slowing down the cancer rate increase and preventing many cases.
Analyzing data from the ICR and Imperial College London, experts found that while several cancer rates have been rising in younger adults over the past two decades, traditional risk factors such as smoking, alcohol consumption, red or processed meat intake, low fiber consumption, and lack of physical activity have remained stable or decreased before diagnosis. This suggests that these factors are unlikely to fully account for the surge in cancer cases, while the steady increase in overweight and obesity since 1995 appears to be a major contributing factor.
Despite the rise in body mass index (BMI) being connected to the increase in cancer among younger adults in England, the study published in BMJ Oncology revealed that other unknown or suspected causes must also be at play. Notably, nine of the eleven cancers studied showed increasing rates in younger adults as well as in older adults, with bowel and ovarian cancers being exceptions, rising solely in the younger age groups.
The research highlighted a faster increase in bowel cancer rates linked to BMI in younger women compared to those not linked to BMI, indicating that other factors are likely influencing this rise. Factors like ultraprocessed foods, antibiotic usage, and air pollution have been suggested but do not fully explain the trend, underscoring the need for a comprehensive examination of all potential causes.
In England in 2023, approximately 31,000 cancer cases were diagnosed in individuals aged 20 to 49, with breast cancer being the most prevalent (8,500 cases), followed by bowel cancer (3,000 cases) and melanoma skin cancer (2,800 cases). Professor Garcia-Closas estimated that a portion of bowel cancer cases in younger individuals can be attributed to being overweight or obese, alongside other known risk factors like lack of exercise, alcohol consumption, and smoking.
Emphasizing the complexity of the situation, the team proposed that a combination of multiple factors rather than a single cause could be driving the increase in cancer cases among young adults. They called for extensive, long-term research studies to identify all potential biological and environmental contributors to the rising cancer rates.
The researchers stressed the urgency of prioritizing public health actions to combat obesity, especially in children and young people, as a crucial step in addressing the escalating cancer rates. Utilizing national cancer registry data from 2001 to 2019, the team underscored the need for concerted efforts to reverse the trend.