Doctors are sounding the alarm over the escalating cancer epidemic among young adults.

While an explosion of colon cancers in under-50s has made headlines in recent years, government scientists have now found that 14 types of cancers are rising among the young.

In what they say is the most comprehensive review of its kind, researchers analyzed data on 2.02million young cancer patients diagnosed between 2010 to 2019, 63 percent of whom were female.

Out of the 33 cancers studied, 14 were found to be rising: Stomach cancer, colon cancer, pancreatic cancer, bone and joint cancer, melanoma, female breast cancer, cervical cancer, uterine cancer, testicular cancer, kidney cancer and four types of cancers of the lymph system.

Overall, across all 33 cancers, diagnosis rates were found to have risen one percent per year on average among 15 to 29-year-olds between 2010 and 2015.

And among 30 to 39-year-olds, rates rose 1.25 percent per year from 2010 to 2016 on average before holding steady until 2019.

The scientists suggested the uptick may be down to advances in surveillance for cancers, but also said rising obesity rates, air pollution and environmental factors like ‘forever chemicals’ could be playing a role.

For five cancers, the study only found that they rose in young people and not in older age groups, suggesting only younger adults were being exposed to a factor raising their risk.

Bailey Hutchins of Tennessee, pictured, died of colon cancer earlier this year at age 26

The five cancers only rising in young adults were: melanoma, cervical cancer, stomach cancer, cancer of the bones and joints, and plasma cell neoplasms — a type of cancer affecting the lymph system.

Among the fastest rising cancers was breast cancer, which rose by up to 1.85 percent per year among young adults, and colon cancer, which rose by up to 1.71 percent per year. 

There was also a 2.63 percent per year rise in kidney cancers among 40 to 49-year-olds. 

Mortality rates also rose for some cancers, including colon, uterine and testicular cancer, but held steady or fell for others.

Researchers are still unsure as to the cause of rising cancers among young adults, and in this study they said, a ‘constellation of factors’ should be considered.

Among the leading theories were rising obesity rates, with scientists saying obesity causes underlying inflammation, which may raise the risk of cancer.

Other theories suggest air pollution, environmental contaminants like ‘forever chemicals’ and additives in ultra-processed foods may be behind the rise.

Advances in cancer detection and changes in screening guidelines could be behind some early diagnoses. 

Dr Meredith Shiels, an immunologist who led the research, and the other researchers, said in the study: ‘In the US, incidence rates of some cancers have increased in early-onset age groups.

‘For many of these cancers, rates have also increased in older-age groups, suggesting that the impact of changes in risk factor prevalence and/or improvements in detection could affect risk across all age groups.’

In the study, researchers analyzed data from the United States Cancer Statistics Database — the official federal source for cancer stats.

Data was analyzed per year from 2010 to 2019 to check for shifts in diagnosis rates.

They did not use more recent data because of the Covid pandemic, which led to far fewer people visiting hospitals to be diagnosed with the diseases. 

Among women, breast cancer, thyroid cancer and melanoma cancer were found to be the most common among young adults.

And among men, colon cancer, testicular cancer and melanoma were the most likely cancers to be diagnosed.

Results showed that, overall, among 15 to 29-year-olds, cancer diagnosis rates rose one percent per year from 2010 to 2015 — but then dropped 0.73 percent per year from 2015 to 2019.

And among 40 to 49-year-olds, there was no significant change over the time period.

The study also detected rises in at least nine cancers among older age groups, those aged 50 to 79 years old.

For female breast cancer, cases rose by 1.85 percent per year on average among 15 to 29-year-olds and 0.94 percent among 30 to 49-year-olds.

For colon cancer, cases rose 1.69 percent per year on average for 30 to 39-year-olds and 1.71 percent per year among 40 to 49-year-olds.

And for kidney cancer cases rose 2.63 percent among 40 to 49-year-olds, but remained stable for other groups.

The researchers said that this translated to an extra 4,834 young women being diagnosed with breast cancer every year in the US compared to a decade ago. 

While an extra 2,099 young adults are diagnosed with colon cancer, 1,793 extra are diagnosed with kidney cancer and 1,209 are diagnosed with uterine cancer.

Although the numbers may seem small, they are a major increase when considering that in 2010, there were about 43,000 women under 50 years old being diagnosed with breast cancer.

Evan White, shown above, lost his four-year battle with colon cancer at age 29

Carly Barrett, from Kentucky, was diagnosed with colon cancer at age 24 after detecting blood in her stool and suffering from abdominal pain. She is still battling the disease

Explanations for why cancer cases are rising among young adults are still yet to be revealed.

‘Several of these cancer types are known to be associated with excess body weight and so one of the leading hypotheses is increasing rates of obesity,’ Dr Shiels added.

For breast cancer, the trend toward women having a first child at older ages is a possible explanation. Pregnancy and breastfeeding are known to reduce the risk.

The study was funded by the Intramural Research Program of the National Cancer Institute of the National Institutes of Health and the Institute of Cancer Research — which are federal agencies.