Health. Why cancers are increasingly affecting people under 50, like Kate

It’s a real “epidemic”, summarizes cancer specialist Shivan Sivakumar, researcher at the University of Birmingham. Between 1990 and 2019, the cancer rate almost doubled (+80%) among those under 50 across the world, assesses a large study published in 2023 by the BMJ Oncology. The phenomenon, which particularly affects developed countries, also results in an increase in cancer deaths among those under 50. In thirty years, their number has increased by some 28%.

Some cases have struck the general public, such as the death at age 43 of actor Chadwick Boseman, star of Black Panther, following colorectal cancer in 2020. In fact, gastrointestinal cancers – colon, esophagus, liver, etc. – are the subject of a particularly notable outbreak among young people. According to the American Cancer Society, they are the leading cause of cancer death among men under 50, and the second leading cause of death among women of the same age, behind breast cancer.

How to explain such a phenomenon ?

We don’t know and the answer is surely complex. “At present, there is no conclusive evidence” to favor an explanation, explains Dr. Sivakumar. It is likely that several factors are involved. An explanation, popular in vaccine skeptic circles, can however be quickly dismissed: anti-Covid vaccination has nothing to do with the increase in cancers among young people, since this phenomenon had been underway for a long time before the pandemic. Researchers rather favor two main avenues. Either recent generations have been more exposed than their predecessors to well-known risk factors. Or new risks have emerged.

The first category of hypotheses is notably fueled by an observation: compared to previous generations, current forty-year-olds were younger when they experienced smoking, alcohol consumption or obesity. The last point particularly attracts the attention of epidemiologist Helen Coleman, of Queen’s University in Belfast. The researcher, who has particularly studied cancers among young people in Northern Ireland, points to an “obesity epidemic” which did not exist before the 1980s.

There remains the other major hypothesis, which suggests the appearance of new carcinogens. There are many theories – chemicals, microplastics, new drugs… – but all remain speculative. Objects of strong media attention, ultra-processed foods have recently been cited as a possible culprit. But, again, “there is really very little data to support this idea,” notes Professor Coleman.

How to overcome ?

Without knowing the root causes of the phenomenon, it is difficult to know what to do to stop the increase in cancers among young people. For some health authorities, screening is a crucial tool. The United States has therefore lowered in 2021 to 45 the age at which it is recommended to be screened for colorectal cancers. In France, the minimum age remains set at 50 years, but some gastroenterologists advocate a lowering.

More generally, researchers hope that the case of the Princess of Wales will draw the attention of young people to the fact that cancer does not only strike the oldest. And if in doubt about a symptom, it is better to consult. “If you feel that something is wrong, don’t waste time: go and get yourself checked,” concludes Dr. Sivakumar.