No wrinkles, not even white hair, but already a tumor, which is swelling. Before Kate Middleton, many young celebrities announced they were suffering from cancer, making headlines. Like the France Info journalist, Clémentine Vergnaud, 31, died last year, after a year and a half of bearing witness to her fight. Or her colleague, at BFM TV, Virgilia Hess, 34, who suddenly disappeared from the air, forced to undergo chemotherapy.
Each time, age surprises. Don’t we say that these pathologies, whose development is most of the time very slow, occur especially over the years? French reality TV star Caroline Receveur is only 36 years old. Sick, too. American actress Olivia Munn is barely older: 43 years old. Her cancer was, she says, “aggressive”: she had to have both breasts removed. Chadwick Boseman, known for his role in Black Panther, was the same age. He died in 2020.
The examples are accumulating so quickly that some oncologists no longer hesitate to speak of an “epidemic” among those under 50. Like this American expert, cited by Agence France Presse, in a dispatch written in reaction to Kate Middleton’s comments, on March 27. It was broadcast by around ten media outlets, without them checking whether this opinion was a consensus in the scientific community. Since then, the term has continued to circulate.
An epidemic of misinterpretations
An epidemic of early tumors, really? Regularly questioned on this subject by The Express over the last six months, the main institutions responsible for monitoring cancers in France (the National Cancer Institute, Public Health France) have nevertheless been categorical: there are none, neither in France, nor on a national scale. of the planet. At issue: a chronic misinterpretation of the figures on the subject, and more particularly of a study, very regularly relayed since its publication in September 2023 in the British Medical Journal (BMJ).
According to this scientific article, the number of tumors appearing before the age of 50 has jumped by 79% in thirty years. The figure is waved everywhere. Except that as it stands, it is not possible to use it to gauge the spread of these diseases. Because the population also increased over the same period, by more than 50%, which distorts the calculation. Likewise, it is impossible to draw conclusions from a global average: exposure to carcinogens and the means to protect against them vary greatly from one country to another.
Other elements can also be mentioned: normally, we analyze the evolution of the incidence of the different tumors separately – skin cancer rarely has the same origin as bladder cancer. Finally, the article does not detail what is happening in other categories of the population, nor the developments in different screening policies around the world. However, the earlier we test, the earlier we find cancers, as recalled by a scientific analysis published in the journal Nature in 2022. This logic explains many jumps in the different censuses, insist the authors.
Thus, if the study of BMJ is not false, it in no way provides the answer to the question of the evolution of the “risk” of cancer in young people. Still, with all these stars sick young, the question deserves to be asked: is the risk evolving? “At this stage, the data at our disposal do not allow us to conclude in this direction,” says Catherine Hill, epidemiologist at Gustave Roussy, annoyed to see that most of the scientific papers cited are careful not to compare their figures with other classes. of age.
In France, the curves overlap
However, just open the last one epidemiological bulletin from Public Health France, the main source on the subject in France. Inside, all the curves overlap, regardless of age. Breast cancer is exploding among young people? It increases as much among those over 50. And so on: “When it climbs, it climbs everywhere,” summarizes Catherine Hill. Even when we draw a curve taking into account all national cancers, in women, and in men, the observation is the same: “there is no specific dynamic among young people”, she continues.
In France, no specific increase in cancers among young people, but several alerts. Weekly epidemiological bulletin, Public Health France. July 2023.
© / Public health France
Exit therefore, the mysterious evil which would grow on young people in particular, almost everywhere in the world, all organs combined. Which does not mean that there are not warnings about certain cancers. Most of them can be explained quite easily, by an increase in risky behavior. Yes, skin cancers are more and more numerous, even among young people, but a priori, no secrets: tanning is fashionable. However, the sun’s rays, in high doses, disrupt our cells. Same with breast cancer. Same dynamic, mainly due to the increase in smoking and alcoholism among women. Developments described for years by specialists.
So everything is explained, and under control? There are still some puzzles left. Science does not yet explain everything. In the United States, cancers of the digestive system, that is to say the colon, rectum, and stomach, have been increasing among those under 50 since 1990. An anomaly, which is causing increasing concern oncologists. Especially since among adults aged 65 to 74, the curve is reversed: the trend is rather downward, as shown by a study published in March 2023 in Cancer Discovery. Scientists tested for known carcinogens, such as alcohol, tobacco, physical inactivity and poor diet. They do not, on their own, explain the phenomenon among young people.
Faced with this mystery, the United States decided, as a precaution, to lower the recommended age for testing to 45, and launched research. The health authorities of different developed countries are monitoring their data a little more closely. Because while this might be a uniquely American problem, there are still important similarities in Western lifestyles. The first warning signals have also emerged in Europe. According to a study published in 2019 in the BMJ, colorectal cancers increased by 7.9% each year among 20-29 year olds between 2004 and 2016. It is 4.9% among 30-39 year olds, and 1.6% among 40-49 year olds. On average, they decrease in other generations.
Specific alerts
However, there is no consensus on these data. Here too, establishing an average on a European scale poses a problem: exposure to carcinogens is not the same in Italy or Sweden. And above all, cancers are very rare under the age of 50. They represent less than 10% of cases, even less if we only count those which affect the digestive system. That their number doubles, triples or quadruples therefore does not allow us to deduce a trend, warn epidemiologists. The risk of false results is so great that in France, the National Cancer Institute, the body responsible for these statistics, only records them from the age of 40, to have a sufficiently large sample.
In the absence of visibility, and faced with these signals, certain French scientists still decided to take the lead. Among them, Alice Boilève, head of clinic, specialist in this type of condition. In his office, young people have been jostling for several years. With her team at Gustave Roussy, she therefore decided to launch this year a study project called YODA For Young Onset Digestive Adenocarcinoma. The goal: to compare the cancers of juniors and those of seniors, to verify the role of certain pollutants, such as pesticides or plastics. Or even specify the links with the microbiota, these microbes which live in our digestive organs, while ultra-processed food is increasingly suspected of disrupting our organisms.
Especially, whether young or not young, certain cancers are exploding in France, without us really knowing why. That of the pancreas, for example, is increasing in several developed countries, in all ages. “On these pathologies precisely, we can speak of an epidemic, it is indisputable, and in all age groups,” explains Alice Boilève. Here again, known carcinogens alone do not explain the entire phenomenon. Which does not overly surprise doctors: very often, the causes of digestive cancers are diffuse, multiple, unlike those of the lung for example, where the culprit, cigarettes, is obvious.
At Poitiers University Hospital, oncologist David Tougeron and his team have also launched research. As they focus on cures, the issue of age doesn’t matter to them. Still, in the eyes of these specialists, there is urgency, regardless of the debates on the terms to use: “Digestive cancers are more and more common, and serious, with serious consequences for the patient, and in terms of public health”, explains the expert, who regrets that only a third of people entitled to screening at age 50 actually request it. The specialist oversees around forty therapeutic trials, for new drugs and new screenings. In the hope that one day we can cure them.
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