Over the past decade, certain cancers have been on the rise among younger patients, while the rates in older patients have remained stable. This increase in cancer among patients aged in their 20s, 30s, and 40s is naturally a cause for concern, and the underlying reasons behind this trend are not yet fully understood. Although they have been linked to environmental and lifestyle factors, the underlying reasons behind this trend are not yet fully understood.
At the Union for International Cancer Control Congress in Geneva in September, researchers from the American Cancer Society and the World Health Organization’s International Agency for Research on Cancer assessed data from 50 countries to try to determine what was happening to the rates of certain cancers. They reported that in 14 countries, the increase was observed solely in younger adults, while rates in older adults remained stable. The report highlighted rising cases of several cancers in younger age groups, including breast cancer and colorectal cancer. Over the past 10 years, rates of colorectal cancer among 25- to 49-year-olds have increased in 24 countries, including the UK, US, France, Australia, Canada, Norway, and Argentina.
Other studies have also indicated a rise in digestive tract cancers among younger patients in recent years, including pancreatic and liver cancers.
Breast cancer diagnoses have also increased among younger patients. Although the death rate has dropped by around 10% in the past decade due to advancements in diagnosis and treatments, incidence rates are rising by 1% annually overall and by 1.4% per year for women under 50. Breast cancer is known to have genetic risk factors, such as the BRCA1 and BRCA2 gene mutations, but many younger patients presenting with breast cancer have no obvious genetic predisposition to the disease.
Researchers are concerned about the rise in cancer rates in young people and are urging doctors to be more aware of this growing trend, as symptoms can be overlooked in younger patients and not immediately linked to cancer. Often, cancers such as bowel cancer or pancreatic cancer are regarded as diseases of older patients and not the main cause of symptoms in a young, healthy adult. Additionally, tumours in younger patients tend to be more aggressive, making prompt diagnosis important.
Why are cancer rates rising among young people, and what can be done?
With a rise in cancers of the digestive tract, examining dietary habits would be an obvious place to start, particularly the rise in ultra-processed foods and some components of our diet. One theory is that these foods are changing the environment within the gut, causing damage and inflammation that leads to alterations in the DNA of the cells lining the intestines and colon. Another factor could be changes to the gut biome due to dietary shifts; more processed foods, artificial sweeteners, and less fibre, fruit, and vegetables can affect the range of bacteria that naturally colonise our guts.
Research shows that the bacteria in our guts are important for our health in various ways, from aiding digestion to producing essential nutrients and helping with immunity. This relationship has evolved over many years, and the bacteria are not designed to process many of the compounds found in modern processed foods. Related to this is the use of antibiotics, which can also affect the gut biome by killing off healthy bacteria and allowing other pathogens to proliferate instead.
Another factor is the rise in obesity and metabolic syndrome over the past few decades, which have been associated with increasing inflammation in the body and affecting hormonal pathways (e.g., diabetes, polycystic ovary syndrome). Studies have shown that excess body weight increases the risk of several cancers, including ovarian, liver, pancreatic, kidney, and gallbladder cancers. A sedentary lifestyle and poor diet are often underlying causes of weight gain.
However, issues such as obesity do not explain everything, as many patients who are diagnosed are young and fit and otherwise seem healthy. This suggests that other environmental factors could be contributing. Microplastics have emerged as a potential candidate; in recent years, the widespread use of plastics has led to microplastics being present everywhere, including in the food and water we consume. One theory posits that microplastics are affecting our guts and damaging the cells lining our digestive tracts.
Smoking is linked to an increased risk of certain cancers and may also be a factor, although in many countries, smoking rates are now decreasing, and young people are often less likely to smoke than their parents or grandparents.
Another area of interest for scientists is changes in our sleep patterns. With our fast-paced, 24/7 lifestyles, media, and smartphones, significant changes in sleeping patterns have been observed; for example, shift work has become more prevalent in many countries. Studies have also shown that the average sleep duration of children and teenagers declined by around an hour per night between 1905 and 2008.
In addition to reduced sleep, we are exposed to more artificial light through indoor lighting, streetlights, and, of course, the use of laptops and mobile phones. All of this can affect sleep and disrupt our biological clock and the daily rhythm of certain physiological processes, which has been linked to an increased risk of breast, colon, ovarian, and prostate cancer.
It may be that several risk factors are contributing to the rise in cancer among younger patients, and research is ongoing in this area. Whatever the cause, this is a worrying trend. Raising awareness among young people about the potential lifestyle risks can help individuals make informed changes to reduce their risk. General practitioners must also remain vigilant to identify symptoms earlier and ensure prompt diagnosis.
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