An Epidemic of Cancer Diagnoses Is Spreading Among Young Adults, But Is It Real?

A JAMA study shows early-onset cancer diagnoses are soaring, yet death rates stay flat, pointing to overdiagnosis and unnecessary treatment.

BOSTON — Cancer diagnoses among Americans under 50 have skyrocketed in recent decades, spawning alarmed headlines and federal research initiatives targeting what many call an emerging epidemic. High-profile cases involving figures like the Princess of Wales and Chadwick Boseman have amplified concerns that cancer is striking younger adults at unprecedented rates.

But an analysis led by Dr. H. Gilbert Welch of Brigham and Women’s Hospital reveals a startling disconnect: While diagnoses of the fastest-rising cancers in young adults have roughly doubled since 1992, deaths from these same cancers have remained stable. The mortality rate in 2022 was identical to 1992, sitting at 5.9 deaths per 100,000 people in both years.

Rather than facing a true surge in life-threatening disease, young Americans may be experiencing an “epidemic of diagnosis,” one driven by more intensive screening, better detection technology, and lower thresholds for labeling abnormalities as cancer.

“Rising incidence is typically interpreted as a rising occurrence of clinically meaningful cancer that must be attributed to hazardous exposures or behaviors,” the researchers write in their JAMA Internal Medicine paper. “However, rising incidence can also reflect increased diagnostic scrutiny.”

Following the Wrong Signal

Researchers examined eight cancers with the fastest-growing rates among adults under 50: thyroid, anus, kidney, small intestine, colorectum, endometrium, pancreas, and multiple myeloma. Each increased by more than 1% annually on average between 1992 and 2022.

When researchers tracked both diagnosis rates and death rates for these cancers, a pattern emerged. Collectively, these eight cancers showed a near-perfect split between surging incidence and flat mortality, the classic signature of overdiagnosis.

Overdiagnosis refers to the detection of disease that would never have caused symptoms or death. Thyroid cancer provides the clearest example. Diagnoses exploded during the study period, yet mortality remained extraordinarily stable. More than 200,000 additional young Americans received thyroid cancer diagnoses since 1992, while the number of deaths stayed virtually unchanged.

Similar patterns appeared for kidney cancer, where diagnoses climbed rapidly while mortality actually fell, and for small intestine and pancreatic cancers, where rising diagnoses appear to reflect the incidental discovery of small, slow-growing neuroendocrine tumors on imaging scans or during endoscopy procedures.

For multiple myeloma, about a third of patients now arrive at diagnosis with no symptoms, their cancer discovered through routine blood work that has become more common.

Only two of the eight cancers showed mortality increases that aligned with rising diagnoses: colorectal and endometrial cancer. Even for colorectal cancer, however, the mortality increase (about 0.5% annually since 2004) lagged far behind the rise in diagnoses (roughly 2% per year), raising questions about whether some of those additional cases represent clinically meaningful disease.

The Breast Cancer Exception

Breast cancer, while not among the fastest-growing cancers in relative terms, tells an instructive story. It remains the most common cancer diagnosed in women under 50, and diagnoses have risen modestly but steadily over three decades.

Deaths, however, have fallen by approximately half during the same period, thanks to major advances in treatment. The number of excess breast cancer diagnoses since 1992 has exceeded 100,000, yet the number of excess deaths is negative.

Researchers note that rising breast cancer incidence in younger women has occurred almost entirely in early-stage disease, with stable rates of regional and distant cancers. It’s the same pattern observed in older women after widespread adoption of screening mammography in the 1980s. The trend appears to reflect increased screening intensity through mammograms, ultrasounds, and MRI scans rather than a true increase in dangerous breast cancers.

Comparing Diagnoses to Deaths

Death rates provide a more reliable measure of cancer burden than diagnosis rates because mortality is far less affected by how hard doctors look for disease. While cause of death can occasionally be misclassified, the researchers argue that mortality trends offer the clearest window into whether cancer occurrence is genuinely rising.

When diagnoses climb but deaths don’t, two explanations typically emerge. One possibility: improved treatment is saving patients who would have died in earlier decades. Another: doctors are simply finding more cancers that were always there but never would have killed anyone.

For these trends to reflect improved treatment alone, advances would need to perfectly counterbalance rising disease, saving just enough lives to keep mortality flat. The researchers call this scenario implausible.

A third possibility exists for some cancers: earlier diagnosis. A cancer once caught at age 52 might now be detected at 48 thanks to more sensitive tests, creating the appearance of rising rates in younger patients without any real change in disease occurrence. But if earlier diagnosis were the primary driver, diagnoses in older age groups should decline proportionately, which hasn’t happened.

Real Increases, Real Problems

The analysis doesn’t dismiss all rising cancer rates as artifacts of detection. Colorectal cancer mortality has increased slightly since 2004, though some of that rise may involve tumors of uncertain clinical significance. Endometrial cancer shows parallel increases in both diagnoses and deaths, likely driven by rising obesity rates and declining rates of hysterectomy, which leaves more women at risk.

Overall cancer mortality for Americans under 50 has dropped by nearly half since the 1990s. That’s a genuine public health victory that has received far less attention than rising diagnosis rates.

Cancer deaths also comprise only 10% of all deaths in adults under 50. Suicides and unintentional deaths from causes like drug overdoses and car accidents kill young Americans at more than four times the rate of cancer, and both categories are rising.

When Cancer Diagnoses Are ‘Unnecessary’

“Unnecessary cancer diagnoses carry serious consequences, particularly for young adults. A cancer diagnosis can transform someone who feels perfectly healthy into a lifelong patient, with treatment that may cause infertility, long-term organ damage, and secondary cancers.

The emotional burden extends beyond the individual. Anxiety and depression linked to a cancer diagnosis can persist for years and affect families and communities. Financially, the costs multiply through ongoing surveillance, follow-up care, and management of treatment side effects. For young adults juggling student debt and child care expenses, the financial strain can be catastrophic.

The analysis also raises concerns about resource allocation. Federal initiatives like the Cancer Grand Challenges program have committed $25 million to uncovering biological causes for rising early-onset cancer rates. Research interest has surged, with publications related to early-onset cancer more than tripling over the past 30 years.

Policy has shifted too. The U.S. Preventive Services Task Force recently lowered recommended screening ages for both colorectal cancer (to 45) and breast cancer (to 40), partly in response to concerns about rising rates in younger adults.

If much of the increase reflects overdiagnosis rather than more severe disease, these efforts may be chasing the wrong target and potentially exacerbating the problem by encouraging even more screening.

An Epidemic of Diagnosis

The rise in early-onset cancer appears to be less an epidemic of disease and more an epidemic of diagnosis. While some increase in clinically meaningful cancer is likely real, it appears small and limited to a few cancer sites.

Interpreting rising incidence as a crisis may lead to unnecessary screening and treatment while diverting attention from more pressing health threats facing young Americans. Searching for biological causes of rising incidence in cancers without evidence of increased mortality, the authors argue, may be unproductive.

Moving forward, the challenge will be refining diagnosis to detect and treat only the cancers that truly matter — a distinction that remains frustratingly difficult to make at the moment of detection. What’s becoming more common isn’t necessarily the disease itself, but rather the diagnosis—and those are two very different things.