Cancer Under 50 Is Rising, Bowel Cancer Most Clearly, but It Remains Uncommon

Cancer in adults under 50 has become more common in many countries, and bowel cancer shows the clearest and most widespread rise. It is still uncommon at these ages: in the United States, about 13 in every 100,000 adults aged 20 to 49 are diagnosed with bowel cancer each year, against about 153 in every 100,000 people aged 65 and over.^[1]

Behind the statistics are people diagnosed in the middle of building careers, raising young children or caring for parents, sometimes after symptoms that they, or the clinicians they saw, did not connect with cancer because of their age. They deserve two things from the evidence at once: an honest account of a change that is real for some cancers, and a sense of scale that does not turn a small absolute risk into fear. Researchers do not yet know why the rise is happening. This piece, part of our cancer research library, sets out what has been measured, how big it is and which explanations are still hypotheses.

Early-onset cancer cases worldwide rose by 79% in three decades, but counts are not rates

The most widely quoted global figure comes from an analysis of Global Burden of Disease (GBD) estimates, published in BMJ Oncology in 2023. It defined early-onset cancer as cancer diagnosed between the ages of 14 and 49. It estimated 3.26 million new early-onset cases worldwide in 2019, a 79.1% increase in number since 1990, and 1.06 million deaths, an increase of 27.7%.^[2] Breast cancer had the highest incidence and death rates of any early-onset cancer. Among cancers of the digestive system, bowel (colorectal) cancer made up 36.8% of early-onset cases and had overtaken stomach cancer as the most common.^[2]

Those are counts of people, not rates. The world's population grew between 1990 and 2019, so part of the 79% reflects more people living through their twenties, thirties and forties rather than each person's risk going up. The paper does report age-standardised rates, but cancer by cancer rather than as a single headline: rates rose fastest for early-onset nasopharyngeal and prostate cancer, and early-onset liver cancer showed the sharpest fall, an estimated 2.9% a year.^[2] Our study of cancer incidence trends explains why crude counts and age-standardised rates tell different stories. The same paper projected that the number of early-onset cases would rise a further 31% and deaths 21% by 2030; those projections come from a statistical model built on GBD trends, and the authors note that GBD accuracy is limited by the quality of registry data, with "under-reporting and under-diagnosis" in poorer countries likely to cause underestimation.^[2]

Definitions also vary from study to study: "early onset" means 14 to 49 in the GBD paper, 25 to 49 in the 50-country registry comparison below, 15 to 49 in a US registry analysis and 20 to 49 in American Cancer Society reports. Figures from these sources describe overlapping but different groups and are not directly comparable.

Bowel cancer in younger adults is rising in more than half the countries with long-term data

The broadest international comparison, published in Lancet Oncology in 2025 by Sung and colleagues, used registry data from 50 countries and territories in the IARC Cancer Incidence in Five Continents Plus database. It defined early-onset as diagnosis at ages 25 to 49 and compared it with ages 50 to 74. Early-onset bowel cancer incidence rose in 27 of the 50 over their most recent ten years of data, which ran up to 2017. The fastest rises were in New Zealand (an average of 3.97% a year), Chile (3.96%), Puerto Rico (3.81%) and England (3.59%). In 14 of the 27, rates at ages 50 to 74 were stable or falling, and in 20 of the 27 the rise was confined to the younger group or faster than in the older one.^[3]

In Europe, an analysis of 20 countries published in Gut in 2019 found that bowel cancer incidence rose by 7.9% a year at ages 20 to 29 between 2004 and 2016, by 4.9% a year at 30 to 39 (2005 to 2016) and by 1.6% a year at 40 to 49 (2004 to 2016).^[4] The steepest percentage rises are in the youngest groups, where rates start from the lowest base. A GBD analysis of bowel cancer worldwide, published in Lancet Gastroenterology & Hepatology in 2022, likewise reported "a substantial rise in incidence rates" in adults under 50.^[5]

The United States has particularly detailed data. The American Cancer Society's Colorectal cancer statistics, 2026 reports that incidence in adults aged 20 to 49 rose by 1% to 2% a year from the mid-1990s, and the pace accelerated to 3% a year from 2013 to 2022. Over the same years incidence fell by 2.5% a year in people aged 65 and over.^[1] The rise follows generations: an earlier analysis of US registry data found that people born around 1990 had about double the risk of colon cancer and about four times the risk of rectal cancer of people born around 1950, at the same age.^[6] Our study of bowel cancer covers the disease at all ages.

In absolute terms, cancer before 50 is still uncommon, and a small share of all cancer

Percentage changes describe direction; they do not describe size. A rate that rises by 3% a year from a low base remains low for many years. In the United States in 2018 to 2022, bowel cancer was diagnosed at a rate of 13.1 per 100,000 people a year at ages 20 to 49, compared with 68.0 per 100,000 at 50 to 64 and 153.1 per 100,000 at 65 and over.^[1] Put another way, in a typical year roughly one adult in every 7,600 aged 20 to 49 is diagnosed with bowel cancer.

The American Cancer Society projects 158,850 new bowel cancer cases and 55,230 deaths in the United States in 2026; 24,640 of those cases (about 16%) and 3,890 of the deaths (about 7%) are expected in people under 50.^[1] Across all cancers, 12% of US diagnoses are in people under 50, ranging from 1% of prostate cancers and 2% of lung cancers to 17% of breast cancers and 47% of cervical cancers.^[7] The estimated probability of being diagnosed with any invasive cancer before the age of 50, based on 2019 to 2022 US rates, is 3.4% for men and 6.0% for women. Breast cancer is a large part of that difference: a woman's estimated probability of breast cancer before 50 is 2.2%.^[7]

Another way to measure size is to ask how many extra diagnoses rising rates produce. A 2025 analysis of US registry data for 2010 to 2019 found that 14 cancer types rose in at least one early-onset age group (15 to 29, 30 to 39 or 40 to 49). Compared with what 2010 rates would have produced, the largest numbers of additional diagnoses in 2019 were:^[8]

Those are real people, and the numbers matter for services. They are also a small fraction of the roughly 2.1 million new cancer cases projected in the United States in 2026, most of them in older people.^[7]

Part of the rise reflects more looking, but rising bowel cancer deaths suggest it is not all detection

Incidence can rise because more disease is occurring, or because more existing disease is being found. A 2025 analysis in JAMA Internal Medicine by Patel, Adamson and Welch examined the eight cancers with the fastest-rising incidence in US adults under 50: thyroid, anus, kidney, small intestine, colorectum, endometrium, pancreas and myeloma. Together these "have doubled in incidence since 1992, while the aggregate mortality for these cancers has remained flat." In women under 50, breast cancer diagnoses rose while breast cancer mortality fell by about half. The authors concluded that "much of the increase appears to reflect increased diagnostic scrutiny and overdiagnosis", meaning the detection of cancers that would never have caused harm, and warned that treating the trend as an emergency could lead to unnecessary screening and treatment.^[9] A 2022 review in Nature Reviews Clinical Oncology also judged that wider use of screening had contributed "to a certain extent", while finding a genuine rise for several cancer types.^[10] Changes in how tumours are coded can play a part too, as our incidence trends study, linked above, describes for appendix tumours.

Bowel cancer stands out. The same JAMA paper noted slightly rising mortality from colorectal and endometrial cancers.^[9] The US registry analysis found early-onset death rates rising for colorectal, uterine and testicular cancer, while most other cancers showed no matching rise in mortality.^[8] In the United States, bowel cancer mortality in adults under 50 has risen by about 1% a year since 2004, and bowel cancer is now the leading cause of cancer death in adults younger than 50.^[1] Rising deaths are hard to explain by overdiagnosis alone. Across all ages, the US share of bowel cancers diagnosed at an advanced stage also grew, from 52% in the mid-2000s to 60% in 2019, while the share of cases in people under 55 rose from 11% in 1995 to 20% in 2019.^[11]

The picture is not uniform. In the 20-country European analysis, bowel cancer mortality did not change significantly among adults in their twenties and fell among those in their thirties (1990 to 2016) and forties (1990 to 2009).^[4] And in the United States, the American Cancer Society attributes the acceleration since 2013 to a spike in localised-stage diagnoses from 2019, the result of screening uptake among people aged 45 to 49 after the recommended start age was lowered from 50 to 45 by the Society in 2018 and the US Preventive Services Task Force in 2021.^[1] Finding more cancers early is the aim of screening; it also means some of the recorded rise reflects more testing. How survival figures can mislead when diagnosis moves earlier is explained in our guide to survival statistics.

The leading explanations are still hypotheses

The American Cancer Society says early-onset bowel cancer is rising for "reasons that remain largely unknown".^[1] Because the rise tracks birth generations, researchers have focused on exposures that changed across the second half of the twentieth century and may act early in life.^[10] The main lines of evidence are:

• Excess weight. In the US Nurses' Health Study II, which followed 85,256 women, those with a body mass index of 30 or more had 1.93 times the risk of early-onset bowel cancer of women with a BMI of 18.5 to 22.9 (95% confidence interval 1.15 to 3.25). The finding rests on 114 cases among female nurses, and as an observational study it shows an association, not proof that weight caused any cancer.^[12]
• Gut bacteria. A 2025 Nature study of 981 bowel cancer genomes from 11 countries found DNA damage patterns linked to colibactin, a toxin produced by some gut bacteria, 3.3 times more often in people diagnosed before 40 than in those diagnosed after 70. The patterns appeared to have been acquired early in the tumours' development. The authors concluded that early-life exposure to these bacteria "may contribute" to the rise.^[13]
• A changed "exposome". The 2022 review argued that "substantial multigenerational changes in the exposome have occurred" since the mid-twentieth century, in diet, lifestyle, body weight, environment and the microbiome, possibly interacting with genetic susceptibility, while noting that "the effects of individual exposures remain largely unknown".^[10]
• Alcohol and tobacco. The GBD analysis modelled alcohol use and tobacco, together with dietary factors, as the main risk factors behind early-onset cancer as a whole.^[2] These are modelled estimates of attributable cancer, not measurements of what caused the rise.

Inherited risk matters for individuals and families, but on its own it is unlikely to explain a rise that follows birth generations. A 2026 meta-analysis in Lancet Gastroenterology & Hepatology found that 17.7% of people diagnosed with bowel cancer before 50 who had multigene panel testing carried an inherited variant, with yields falling as age at diagnosis rose.^[14] None of these explanations has been shown to account for the trend on its own, and none of them means that an individual caused their own cancer.

What the evidence asks of us

The evidence does not support alarm, and it does not support complacency either. For bowel cancer in particular, rates and deaths in younger adults are rising in many high-income countries, and nobody yet knows why. That points to several things services, funders and policymakers can do.

• Fund research into causes, built to last. The exposures under suspicion act over decades, beginning in childhood. The 2022 review concluded that finding them will "require prospective cohort studies with dedicated biobanking and data collection technologies".^[10] That is long-term, unglamorous funding that only governments and large research funders can sustain.
• Take symptoms in younger adults seriously. The review called raising awareness "among both the public and health-care professionals" critical, and the American Cancer Society calls for clinician and public education about bowel cancer symptoms and more attention to the particular needs of younger people with the disease.^{[10] [1]} Our study of symptoms and diagnostic delays sets out how long the journey to diagnosis can take.
• Decide screening ages on benefits and harms, country by country. The United States lowered its recommended bowel screening start age to 45.^[1] Whether other countries should follow depends on their own rates, their screening tests and capacity, and the risk of overdiagnosis that the JAMA analysis warns about.^[9] These are decisions for national screening committees, made in the open.
• Improve the data where it is weakest. Most of the trend evidence comes from high-income countries. The GBD authors note that under-reporting in poorer countries likely leads to underestimation.^[2] Better registries are a precondition for knowing whether the pattern is global.
• Report absolute risk alongside relative change. Headlines that say "up 80%" without the base rate frighten people and help no one.

Language: this piece says "people with cancer" and "people living with and after cancer", and describes the illness and its treatment plainly, without combat metaphors. Clinical terms such as "stage", "incidence" and "net survival" are used in the sense the cited source defines them.

Why we're publishing this

People diagnosed with cancer in their twenties, thirties and forties often describe feeling out of place, in waiting rooms and support groups designed around older people. Charities working with younger adults need figures they can stand behind, both to argue for faster diagnosis and research funding and to answer frightened questions honestly. We have set out the rise, its true size and the open questions in one place, so that the case for action rests on evidence and nobody has to choose between being heard and being accurate.

How to read this data

Three kinds of evidence appear here. Registry trends (the US, European and 50-country analyses) count diagnosed cancers in defined populations; they are the strongest evidence that rates are changing, but they cannot separate more disease from more detection. Modelled global estimates (the GBD figures) fill gaps where registries are missing, so they carry more uncertainty, especially for low- and middle-income countries. Studies of causes (the nurses' cohort, the genome study) show associations or biological clues, not proof of what drove the trend.

Watch the measure. Counts of cases rise with population growth; rates per 100,000 do not. "Early onset" is defined differently between studies, so figures from different papers are not directly comparable, and the latest international registry comparison runs only to 2017. Most of the detailed evidence comes from the United States, Europe and other high-income countries. Some figures are taken from abstracts only; where that is the case we have used only what the abstract states.

Use this data

Free to cite with attribution to Better Health For Everyone. Charities, campaigners and journalists are welcome to reuse these figures and charts. For the underlying figures as a spreadsheet, get in touch.

Important: This article summarises published research for general information. It is not medical advice and cannot be used to diagnose, treat or predict anything about an individual. If you have concerns about your own or someone else's health, please speak to a qualified health professional.

Sources

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