Viral US breast cancer stats misinterpreted

A post on X (formerly Twitter) by independent parliamentary candidate for North West Leicestershire Andrew Bridgen, claims to present data on the rising number of breast cancer cases in women in the US under the age of 45 between 2019 and 2023. Similar posts have also appeared on Facebook and Instagram.

The screenshot in the post shows an increasing number of breast cancer cases, with a large jump in numbers particularly between 2022 and 2023. 

This is accompanied by the words “something big happened”. Some of the comments under the post refer to vaccines and we’ve written before about false claims that Covid-19 vaccines cause cancer.

However, this post is misleading. The numbers in the image do not represent breast cancer cases in women under 45 only. Instead, they are similar to the projected number of breast cancer cases for various age groups.

The safety of vaccines and other medications is continually monitored by the Medicines and Healthcare Products Regulatory Agency in the UK and other organisations in the US.

Bad information can impact the decisions people choose to make about their own health. Public figures should take care not to spread misleading information. We have contacted Mr Bridgen, who was still an MP when the post was published, and will update this article should we receive a reply.

Where do these figures come from?

These figures are also featured in an Instagram video posted in 2023 where a woman reads out some of the same numbers which she claims represent deaths from breast cancer in women under 45 years of age. The woman goes on to say “don’t worry, it has nothing at all to do with the shot”.

This video was debunked by other fact checkers shortly after it was posted.

The first three figures in the screenshot all represent the estimated number of new cases of breast cancer for women under 45 years and not the actual breast cancer numbers. 26,660 is the estimated number for 2019, 26,500 is for 2020 and 26,510 is for 2021.

These figures come from the American Cancer Society, which provides annual reports on projected cancer cases in the US, which are based on the actual number of cancer cases that developed in the preceding years. They provide details for a range of cancer types, including information on cancer deaths and projected cases, which helps to track trends. Estimates are used because the actual data lags behind by a few years. 

These estimates are calculated using data from the preceding few years and may not be exactly the same as the actual number of cases that go on to develop.

The next figure of 47,000 seems to represent the estimated number of cases in women under 50 years for 2022 and not just those under 45. Rebecca Siegel, the American Cancer Society’s senior scientific director of cancer surveillance research, told Politifact that the change in the age range was made “to be more consistent with the convention for early onset cancers”.

The 2023 figure of 297,000 appears to be roughly the estimated number of new breast cancer cases across all age groups that year. The estimated figure for cases in women under 50 in 2023 was actually 48,780. 

There has been an increase in the number of women with breast cancer over the years and this is thought to be partly due to reproductive trends and increasing excess weight which are recognised risk factors.

For context, there are around 56,000 new cases of breast cancer in women per year in the UK compared with around 400 new cases in men. There has also been an overall increase in the number of cases in the UK over the past two decades.

Breast cancer has been the most common cancer in women in the majority of countries in recent years according to WHO. It is the second highest cause of cancer-related deaths for women in America, however death rates have been decreasing steadily since the late 1980s.