Misleading: While breast self-exams can be helpful in detecting abnormalities in breast tissue, they lack the sensitivity of mammograms, particularly in terms of early detection of cancer.
FULL CLAIM: “Many say self examination is just as effective” as a mammogram; thermograms use thermal images and temperature data to identify problem areas within the breast and allow for earlier detection than mammograms, which show changes when there is already a problem
REVIEW
Mammograms are a useful screening tool for early detection of breast cancer given that they help identify potential issues before they become palpable or symptomatic. They use X-ray imaging to examine breast tissue for signs of abnormalities, such as tumors or calcifications. The Breast Cancer Research Foundation considers mammograms to be the “gold standard in breast cancer screening”.
During a mammogram, each breast is positioned and compressed between two plates to take X-ray images from different angles. These images are then evaluated by a radiologist for signs of cancer.
Because mammograms use a low dose of radiation, one popular breast cancer myth is the claim that mammograms cause cancer. Science Feedback previously reviewed this claim and found that the benefits of mammograms in early detection of breast cancer outweigh the potential risks associated with X-ray imaging. Scientific studies also show that periodic mammography screening is associated with reduced breast cancer mortality[1,4-6].
Mammograms aren’t the only method for breast cancer screening. Physical examinations, including clinical breast exams performed by healthcare professionals, and breast self-exams, can also help detect breast cancer by identifying abnormalities such as lumps in breast tissue.
However, certain screening methods for breast cancer are sometimes touted as adequate substitutes for mammograms. Such claims occasionally circulate on social media, as with Facebook posts published in October 2024, claiming that breast self-exams and thermograms are as effective as mammograms. As we explain below, these claims are unsubstantiated.
Thermograms aren’t a substitute for mammograms
Thermograms (also referred to as thermal imaging) sometimes circulate on social media as an alternative to mammograms given that they don’t use radiation to collect imaging.
A Facebook post published on 6 October 2024 by the account Hormones Balance reiterated this claim, adding that “mammograms show changes when there’s already a problem” and are thus “not conducive for early detection”, whereas thermograms “allow for earlier detection” by using “thermal images & temperature data to identify problem areas within the breast”.
Thermograms use an infrared camera to detect areas of heat on or close to the surface of the body to produce an image reflecting such “hot spots”. The idea behind thermography as a cancer screening tool stems from the notion that cancerous tissue differs in temperature from healthy tissue, and that thermal imaging thus highlights these temperature differences[2].
Figure 1 – Mammogram vs. thermogram imaging of breast tissue. Source: U.S. Food and Drug Administration.
However, the U.S. Food and Drug Administration (FDA), which is responsible for regulating medical devices including those used for breast cancer screening, hasn’t cleared thermograms as a primary screening tool for breast cancer. In a Consumer Updates article from their website, the FDA cautioned:
“One of the greatest risks from thermography is that those who opt for this method instead of mammography may miss the chance to detect breast cancer at its earliest stage. Thermography devices have only been cleared by the FDA as an ‘adjunctive’ tool, referring to use alongside a primary screening test like mammography. Patients who undergo a thermography test alone should not be reassured of the findings because the device was not cleared to be used without another testing method like mammography.”
The FDA further noted that they take “regulatory action against thermography device manufacturers who market thermography devices as an alternative to mammography”.
In an interview with the MD Anderson Cancer Center, diagnostic radiologist Ethan Cohen pointed out that “[t]here’s no way to follow up abnormalities with thermography. If someone has an abnormal thermogram, they have to start over and come back to us and get a mammogram.”
He added:
“Some research has shown that thermography may be able to detect big, advanced cancers. […] Unfortunately, detecting large, later-stage cancers is not as beneficial. You’re not changing outcomes by detecting advanced cancer. You’re changing outcomes when you find small, clinically undetectable breast cancer.”
In sum, the claim that thermograms are an adequate replacement for mammograms in early detection of breast cancer is inaccurate.
Breast self-exams are a helpful screening tool, but lack the sensitivity of mammograms
A Facebook post shared on 14 October 2024 claimed “[m]any say self-examination is just as effective [as a mammogram]”. The account that shared the post, WOW PBX, had just under 250,000 followers at the time of writing and appears to be run by Danica Walker.
While breast self-exams can help women become familiar with their breasts and notice changes, they’re not a one-to-one substitute for mammograms.
The Mayo Clinic says that “[m]ost medical experts don’t recommend routine breast self-exams as a part of breast cancer screening. That’s because breast self-exams haven’t been shown to be effective in reducing deaths from breast cancer.”
One large randomized controlled trial of nearly 270,000 Chinese women supports this conclusion. In the study, researchers found no difference in breast cancer mortality between those who were instructed to perform regular breast self-exams and those who did not[3].
Further, breast self-exams lack the sensitivity of mammograms for a few reasons.
First, self-exams rely on a person’s ability to feel lumps or changes in breast tissue. Some breast cancers may be too small or located in areas that are difficult to feel, which means they may not be detected in a self-exam. Those with dense breast tissue may find it particularly challenging to detect abnormalities since tumors can be obscured by the surrounding tissue.
Second, mammograms provide a more detailed picture of both breasts. The concrete images provided by a mammogram share more objective results than do breast self-exams, particularly given that they’re evaluated by trained professionals rather than by the person conducting the self-exam. Self-exams are subjective and can vary widely in technique and thoroughness.
Mammograms do have some limitations, but on the whole remain the best screening method for early detection of breast cancer
As Science Feedback shared in a previous review, multiple studies have shown that regular mammograms contribute to reduced breast cancer mortality[1,4-6].
This is in part because mammograms are able to detect potentially cancerous tumors and calcifications earlier than other screening methods. The American Cancer Society explained how this early detection can lead to earlier, less aggressive treatments and in turn reduced mortality:
“Results from many decades of research clearly show that women who have regular mammograms are more likely to have breast cancer found earlier, are less likely to need aggressive treatments like surgery to remove the entire breast (mastectomy) and chemotherapy, and are more likely to be cured.”
Although mammograms are considered the most effective method for early detection of breast cancer, they do present some limitations. The 14 October 2024 Facebook post from WOW PBX shared some of these limitations; specifically, that mammograms can lead to overdiagnosis and unnecessary treatments.
It’s true that mammograms can lead to overdiagnosis and resulting overtreatment. Slow-growing tumors that may never pose a threat to health are sometimes identified through mammograms, in turn causing people to undergo unnecessary cancer treatments.
Mammograms sometimes also show false positives, which indicate the presence of cancer when there isn’t any. This can lead to unnecessary anxiety, additional testing, and invasive procedures like biopsies, which can be distressing for patients.
These limitations highlight the ongoing debate about the balance between the benefits of early detection and the risks of over-treatment. They emphasize the need for patients to discuss screening strategies with their healthcare providers based on individual risk factors, such as family history, age, and breast density, among others.
Conclusion
Thermograms lack FDA approval as a primary screening tool and may lead to missed early-stage cancers, and breast self-exams can be insufficient for detecting small or hidden tumors. Although mammograms do have some limitations, experts nevertheless recommend them as a primary screening tool for breast cancer given their ability to identify abnormalities before they become symptomatic. This early detection in turn contributes to reduced breast cancer mortality.
REFERENCES
- 1 – Duffy et al. (2020) Effect of mammographic screening from age 40 years on breast cancer mortality (UK Age trial): final results of a randomised, controlled trial. The Lancet Oncology.
- 2 – Resmini et al. (2021) A hybrid methodology for breast screening and cancer diagnosis using thermography. Computers in Biology and Medicine.
- 3 – Thomas et al. (2002) Randomized Trial of Breast Self-Examination in Shanghai: Final Results. Journal of the National Cancer Institute.
- 4 – Otto et al. (2012) Mammography Screening and Risk of Breast Cancer Death: A Population-Based Case–Control Study. Cancer Epidemiology, Biomarkers & Prevention.
- 5 – Duffy et al. (2020) Mammography screening reduces rates of advanced and fatal breast cancers: Results in 549,091 women. Cancer.
- 6 – Coldman et al. (2014) Pan-Canadian Study of Mammography Screening and Mortality from Breast Cancer. Journal of the National Cancer Institute.
