Is cancer catching you early now?

I have been reading a lot of reports, including a comprehensive one on BBC, about a worrying trend of early onset of almost all types of cancers. I have my own doubts about all such reports. My own understanding is the rise in cancer cases has more to do with the expansion of detection and diagnostic technology coupled with growing awareness and greater access to public healthcare, and less about cancer itself becoming more pervasive, though that’s not deniable.

Cysts, tumours that develop into cancers keep forming in the body, which has its own mechanism to destroy them. This fight happens all the time in the body. Sometimes, the body fails. A cell grows abnormally big. Others join. Cancer takes roots and branches off subsequently until it is killed by medical aid or it kills the body.

But the trend that I have observed in reports merits our attention. So, The Free Pen is back with an informative article, drawn from various sources.

A significant and concerning trend has been observed globally in recent years—rising cases of cancer among younger adults, particularly those in their 20s, 30s, and 40s. Early-onset cancers, such as colorectal, breast, and others, are becoming increasingly common, presenting a worrying challenge to healthcare professionals.

Over the past decade, colorectal cancer rates in individuals aged 25 to 49 have increased in 24 countries, including the UK, the US, France, Australia, and Canada. At the Union for International Cancer Control (UICC) congress in September 2024, a team of international researchers from the American Cancer Society (ACS) and the World Health Organization (WHO) presented preliminary findings based on data from 50 countries. The study revealed that in 14 of these countries, rising cancer rates were limited to younger adults, with no significant changes in older populations.

These findings add to a growing body of evidence indicating a marked increase in various cancers among younger people. A global study found that between 1990 and 2019, early-onset cancer incidences rose by 79%, with cancer-related deaths in younger adults climbing by 29%. Another report in The Lancet Public Health highlighted similar trends in the US, with rising cancer rates across 17 types of malignancies, particularly among Generation X and Millennials.

One cancer that exemplifies this rise is breast cancer. While deaths from breast cancer in women have decreased by about 10% in the past decade, the incidence rate has been rising steadily by 1% annually, and by 1.4% per year among women under 50. This growing trend has prompted organisations like the UICC to raise awareness among general practitioners, encouraging them to recognise warning signs in younger patients who may not fit the typical cancer profile. Eileen O’Reilly, a gastrointestinal oncologist, warns that younger patients with pancreatic cancer, for instance, often defy expectations: “It’s not uncommon for me to see someone under 40 with pancreatic cancer. These are people in the prime of their lives.”

Traditionally, cancers in younger people were thought to result from inherited genetic factors, such as the BRCA1 and BRCA2 mutations associated with breast cancer. However, the majority of patients with early-onset cancer today exhibit no clear genetic predispositions. Instead, oncologists are seeing more aggressive forms of cancer in these patients compared to older individuals. O’Reilly notes that while younger patients can tolerate treatment better due to their overall fitness, the rapid progression of the disease often results in poor outcomes.

This worrying trend is raising urgent questions about the underlying causes. Many researchers believe that lifestyle and environmental factors may be playing a significant role. Obesity, for example, is strongly associated with an increased cancer risk, as it promotes inflammation and disrupts hormonal pathways. A study revealed that gaining excess weight between the ages of 18 and 40 is linked to an elevated risk of up to 18 different cancers. According to the Lancet report, 10 of the 17 cancers showing increasing prevalence in the US are obesity-related, including kidney, ovarian, and pancreatic cancers.

Shuji Ogino, a Harvard University pathologist and epidemiologist, points out that while genetic variants may confer a small cancer risk, this risk rises significantly when combined with environmental changes. Unhealthy diets, high sugar intake, and chronic insulin resistance all contribute to a higher cancer risk. However, obesity is not the only factor. O’Reilly notes that many younger cancer patients are physically fit and show no obvious risk factors. This has prompted researchers to explore other possible explanations.

One of the overlooked factors could be changes in sleep patterns. Research indicates that global sleep patterns have shifted drastically over the past century, with sleep deprivation becoming more common. Shift work, in particular, has been linked to cancer risk, as disruptions to the body’s circadian rhythms can lower melatonin levels and promote cancer growth. Additionally, the ubiquitous presence of artificial light from streetlights and digital screens may act as a novel carcinogen, further disrupting biological clocks and contributing to cancers like breast and colorectal cancer.

Another emerging area of concern is gut health. There is growing evidence that significant changes in the gut microbiome may be linked to cancer. Excessive antibiotic use, which has increased globally, particularly among children, has been implicated in reshaping the gut microbiome in ways that may promote cancer. Antibiotics have been associated with higher risks of various cancers, including lung, pancreatic, and blood cancers. Similarly, some scientists are investigating whether microplastics could contribute to the rising rates of colorectal cancer. Ingesting microplastics may weaken the protective mucus layer in the colon, potentially increasing the risk of cancer.

Despite the lack of definitive answers, researchers agree that multiple factors, including obesity, poor sleep, antibiotic overuse, and microplastic exposure, are likely contributing to the rise in early-onset cancers. As this worrying trend continues, cancer specialists stress the need for further investigation to understand the drivers behind these changes and to develop strategies for prevention.