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.
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.
A radioactive tracer can be used in a PET/MRI scan, or a gadolinium-based contrast medium used in an MRI scan. But I think you’re right about MRI not actually requiring a tracer.
MRI sometimes uses a non-radioactive contrast depending on what you’re trying to get images of. MRI is probably the safest imaging modality, but it’s very expensive, kind of difficult sometimes due to how long it takes, and isn’t useful for every kind of imaging that needs to be done.