There are rising cases of breast, colorectal and other cancers in people in their 20s, 30s and 40s. What is going on?

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.

  • Dave@lemmy.nzEnglish
    421·
    26 days ago

    TL;DR, the article says obesity rates and sugar account for a lot but not all of the increase so there is probably something else as well. Some suggestions from the article: artificial light, sleep-patterns, changes in biological clock as a result. Microplastics, especially for colorectal cancer. Ultra processed foods. Increased usage of antibiotics.

    Obesity and sugar are presented as known cancer causes while the others are proposed or suggested by experts in the article but nothing to back it up yet, further research needed.

    • acosmichippo@lemmy.worldEnglish
      25·
      26 days ago

      thankfully someone actually read the article (which is pretty bad in terms of accurately representing its citations). One of the other articles cited in OP says:

      Research published in BMJ Oncology found there had been 3.26 million cases in 2019 - 79% more than in 1990. But experts cautioned against reading too much into the findings. The research did not take into account a 40% rise in the total population, while factors such as better reporting may also have played a role. The team, of experts from around the world, including the US, China and the UK, agreed no firm conclusions could be drawn.

      Deaths (as opposed to “incidents”) is a more accurate metric to track since it’s more reliable in terms of detection (obviously) and reporting:

      Cancer killed more than a million under-50s in 2019, a rise of over 25% - but with the 40% population rise, this could actually indicate a falling death rate.

      • Dave@lemmy.nzEnglish
        12·
        26 days ago

        Oh wow, this is really important context. That 79% figure is almost worthless

      • Ephoron@lemmy.kde.socialEnglish
        1·
        25 days ago

        So “no firm conclusions” means what, in terms of the other comments here?

        As far as I can tell, people are understandably a bit troubled, and a bit cross (since some of the proposed causes probably should have been dealt with a lot earlier). They’re maybe hastily jumping to theories about a few likely candidates. Do you blame them?

        Or should we just do nothing? Wait, and put all our faith in…? What?

        The vast majority of the things mentioned would do us absolutely no harm at all to avoid, or even legislate against as a precaution. So is there a good reason we should wait for “firm” conclusions?