LONDON, Oct 05 (BBC): Over the past 10 years, rates of colorectal cancer among 25 to 49 year olds have increased in 24 different countries, including the UK, US, France, Australia, Canada, Norway and Argentina.
The investigation's early findings, presented by an international team at the Union for International Cancer Control (UICC) congress in Geneva in September 2024, were as eye-catching as they are concerning.
The researchers, from the American Cancer Society (ACS) and the World Health Organization's (WHO's) International Agency for Research on Cancer, surveyed data from 50 countries to understand the trend. In 14 of these countries, the rising trend was only seen in younger adults, with older adult rates remaining stable.
The results are the latest in a host of studies detailing a similar rise of a range of different cancers in the young.
Breast cancer is one form of cancer where the trend is apparent. A new report from the ACS found that while deaths from breast cancer in women have dropped by around 10% in the past decade, incidence rates are rising by 1% per year overall - and 1.4% per year for women under the age of 50.
Based on epidemiological investigations, it seems that this trend first began in the 1990s. One study found that the global incidence of early-onset cancer had increased by 79% between 1990 and 2019, with the number of cancer-related deaths in younger people rising by 29%.
Another report in The Lancet Public Health described how cancer incidence rates in the US have steadily risen between the generations across 17 different cancers, particularly in Generation Xers and Millennials.
The issue of early-onset cancers has become such a matter of concern that major organisations such as the UICC are keen to raise awareness of the trend among general practitioners to ensure that warning signs are being picked up among younger patients.
"A doctor listening to somebody above 60 who's talking about difficulty passing stool, feeling tired and bloated, is going to take those symptoms a lot more seriously than a young person in their 30s who's active and doesn't fit the typical profile of a person with cancer," says Sonali Johnson, head of advocacy at the UICC.
"They might put it down to irritable bowel syndrome or work stress, so there's plenty of cases where people's symptoms are dismissed instead of being referred for blood work or a colonoscopy."
Cancer specialists say that patients presenting with diseases like pancreatic cancer, an illness where most people are diagnosed in their early 70s, are sometimes decades younger than would usually be expected.
"It's not uncommon for me to see someone under the age of 40 with pancreatic cancer," says Eileen O'Reilly, a gastrointestinal medical oncologist at Memorial Sloan Kettering Cancer Centre in New York. "It's almost every week, which is a scary thought. These are people in the prime of life, who are starting families and have everything to live for. The implications for society are profound."
