Study shows a dramatic rise in cancer in people under 50

A study by researchers from the US reveals that the incidence of early onset cancers — including breast, colon, esophagus, kidney, liver, and pancreas — has dramatically increased around the world, with the rise beginning around 1990.

In an effort to understand why many more people under 50 are being diagnosed with cancer, scientists conducted extensive analyses of available data, including information on early life exposures that might have contributed to the trend. Results are published in Nature Reviews Clinical Oncology.

“From our data, we observed something called the birth cohort effect. This effect shows that each successive group of people born at a later time — e.g., a decade later — have a higher risk of developing cancer later in life, likely due to risk factors they were exposed to at a young age,” said Shuji Ogino, a professor at Harvard Medical School.

“We found that this risk is increasing with each generation. For instance, people born in 1960 experienced higher cancer risk before they turn 50 than people born in 1950, and we predict that this risk level will continue to climb in successive generations.”

In an extensive review, the team found that the early life “exposome,” which encompasses an individual’s diet, lifestyle, weight, environmental exposures, and microbiome, has changed substantially in the last several decades. They hypothesize that factors like the Western diet and lifestyle may be contributing to the rise in early onset cancer.

The team acknowledged that this increased incidence of certain cancer types is, in part, due to early detection through cancer screening programs. They couldn’t precisely measure what proportion of this growing prevalence could solely be attributed to screening and early detection. However, they noted that increased incidence of many of the 14 cancer types is unlikely due to enhanced screening alone.

Possible risk factors for early onset cancer included alcohol consumption, sleep deprivation, smoking, obesity, and eating highly processed foods. Surprisingly, researchers found that while adult sleep duration hasn’t drastically changed over the several decades, children are getting far less sleep today than they were decades ago. Risk factors such as highly processed foods, sugary beverages, obesity, Type 2 diabetes, sedentary lifestyle, and alcohol consumption have all significantly increased since the 1950s.

Source: The Harvard Gazette

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