SciCheck Compendium: Breast cancer has gradually increased in young women in recent decades. But a social media post misrepresents case projections for 2022 and 2023, falsely claiming they show a dramatic increase in early-onset breast cancer, then baselessly linking its flawed comparisons to COVID-19 vaccines.
By Kate Yandel
Breast cancer in American women under the age of 50 has increased gradually from the mid-1990s to 2019, with a slightly steeper increase starting in 2016. The rate of female breast cancer has also increased slightly in women greater from the mid-2000s to 2019.
According to According to the researchers, these changes are likely due, at least in part, to changes in the age at which people start having children and, in the case of older women, to increased body weight. Being overweight after menopause or having children later in life increases the risk of breast cancer.
The incidence breast cancer decreased for all women and those under 50 in 2020, likely because the disruption of medical appointments during the pandemic led to some cases going undiagnosed. The year 2020 is the last from which official federal statistics on the incidence of this type of cancer are available.
The American Cancer Society (ACS), a nonprofit organization, provides estimates annual number of new cancer cases through 2023, but these projections are based on models that use data of 2019 and prior years.
However, a widely circulated publication in TikTokwhich was also shared in Facebookmisrepresents the ACS projections, using them to give the false appearance of a large surge in breast cancer cases in women under the age of 45 in 2022 and 2023.
The Dr. Ilana Richmana general internist and health services researcher at Yale Medical School who studies cancer detection methods, told us by email that “there are some blatant misrepresentations” in the breast cancer case numbers cited in the video.
The video compares projections of breast cancer cases in different age groups, leading viewers to believe that case numbers are only shown in women under 45 years of age.
“Something is happening here… ’22 and ’23, there is a huge boom in cancer, especially breast cancer in women younger than 45 and under,” says TikTok user James Bishop, a self-proclaimed “expert in numbers” that are identifies himself as a husband, father, musician, retired firefighter, paramedic, and educator.
But Bishop is wrong. The supposed “explosion” of breast cancer is based on the comparison between the number of cases predicted in women younger than 45 years ago and later estimates for all women or those younger than 50 years.
In addition, ACS projections they were not created to assess trends in cancer incidence. and the ACS it states what are you estimates do not “reflect” or “take into account” the effects of the pandemic.
The post also suggests that COVID-19 vaccines caused an increased risk of breast cancer in 2022 and 2023, but no test of a increased risk of cancer behind the vaccination. “There is no mechanistic reason why COVID vaccines could cause cancer,” Richman said.
The video presents false data on the frequency of breast cancer
The video misleads, in part, by showing blurred images of the ACS tables and making it appear that various figures are comparable.
Between 2019 and 2021, Bishop correctly says that the ACS projected about 26,500 new cases of breast cancer each year in women under the age of 45. But for 2022, gives a misleading projection, 47,550, in women under 50 years of age. It does not clarify that this figure reflects a broader age range and instead affirms that they are “twice” as many cases.
“In the US there are about 10 million women between 45 and 50 years. So changing the age cutoff from 45 to 50 increases the size of the population in that age group and will of course translate into a higher number of reported cancer cases,” Richman said. “Women ages 46 to 50 are also at higher risk of breast cancer than those ages 45 and younger.”
The risk of female breast cancer increases until a woman is around age 70, according to an ACS report using data from the National Cancer Institute (NCI) and the Centers for Disease Control and Prevention (CDC). in English). The chance of a woman getting breast cancer is 1 in 1,439 in her twenties, 1 in 204 in her thirties, 1 in 63 in her forties and 1 in 41 in her fifties, according to statistics.
The ACS estimates of total female breast cancer cases called for a slight annual increase in cases, but not a “big change,” according to Richman. “In short, there’s not a huge increase in cancer cases in 2022. The ACS just changed the age groups it used,” she added.
The video continues to be blatantly misleading, with Bishop highlighting the number 297,000 on a chart for 2023 and saying, “and the year isn’t over yet.”
But 297,790 is the number provided of new cases of breast cancer in all women in the US, not just those under 45, which Bishop does not clarify. And this is the expected number of cases for the entire year 2023, not just for the year to date.
“Most breast cancers occur in women over the age of 45, so naturally the number of cases will be much higher in the total US population,” Richman said.
Again, Richman said the total case projection is “not that different” from previous years. “It’s a bit higher, but not times 10, as he implies,” he said, referring to the idea that the number of cases skyrocketed in 2023 compared to 2019 to 2021.
The video states that the equivalent table for 2023 is not yet available, but it is. In women under 50 years of age, the number planned of new cases is 48,780. As we have said, the ACS forecast for 2022 was 47,550. And the total projection of new cases of the ACS for 2022 was 287,850, which does not differ radically from the estimate for 2023 of 297,790.
And as we said, these are projections, not numbers representing actual reported cases, as Bishop leads to believe.
It is important to note that data Bishop inaccurately presents should not be used to infer trends in cancer incidence. The tables that provide the expected cases by age groups say at the end: “Note: Estimates should not be compared with those of previous years.” This is because these estimates are based on modeled data “and vary from year to year for reasons other than changes in cancer incidence,” says the ACS elsewhere on its website.
For example, the ACS claims that update their models over time, and that changes in methodology could lead to apparent changes in cancer incidence.
Richman noted that the number of breast cancer cases depends on factors such as the size of the population and whether the population is aging: a growing or aging population will lead to a greater number of breast cancer cases. For this reason, it is best to monitor for changes using data on incidence, or the “number of cases per person during a defined period of time, often adjusted to account for differences in the age composition of the population over time.” time,” he said.
In addition, the ACS case projections are based on previous incidence statistics from the North American Association of Central Cancer Registries, which draws on data collected by the NCI and CDC. These data provide a comprehensive picture of cancer incidence in the US, but data availability takes several years.
All of the case projections mentioned in Bishop’s video are based on models based on pre-pandemic data, so they cannot capture any trends related to the pandemic.
the researchers foresaw that disruptions in access to care due to the pandemic may have caused a temporary drop in cancer incidence, due to the delay or failure to take examsfollow-up appointments and appointments to ask about new symptoms.
As we have said, this decrease in incidence now appears in the latest detailed national data available. Researchers have hypothesized that an increase in cancer cases may show up in subsequent data as previously undetected diagnoses are made.
Translated by Elena de la Cruz.
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