Canadian women are responsible for deciding on their own breast health management. In consultation with primary care physicians, most choose mammography – the gold standard for breast cancer screening in Canada. Despite this, a growing number of private clinics across Canada offer an unregulated service called “thermography” (also called thermal imaging, infrared imaging, or digital infrared thermal imaging) for breast cancer screening. Thermography has been discussed several times on SBM but as a refresher, it is a digital technique that measures skin temperature using an infrared camera. An image of the heat distribution across the chest, called a thermogram, is interpreted by a thermogram reader and reported to the client in exchange for a fee of up to several hundred dollars.
Does thermography work?
Thermography providers claim that malignancies can be detected by measuring breast skin temperature. They claim that the increased metabolic and vascular activity in tumors will cause an increase in the temperature of the overlying skin. These claims are not supported by science and primary care physicians do not recommend thermography as an alternative to mammography. Sadly, many Canadian women are choosing thermography apparently because the private clinics are very good at advertising.
The premise underlying thermography for breast screening is plausible at first glance. Tumours are indeed metabolically active and, as they grow in size, they recruit blood vessels to deliver the oxygen they need to keep expanding. This extra blood flow brings additional heat and this is what thermography claims to be able to detect. However, regulation of skin temperature is complex and surface (skin) temperature is not a reliable proxy for what is going on in deeper tissues. Thermography was initially investigated as a method for identifying breast malignancies and abnormalities in the 1970s, but scientists found that it showed poor detectability and high false positive rates, and that mammography and clinical examinations were demonstrated to be superior methods of detection for breast cancer.
Recent systematic reviews conclude there is no evidence to support the use thermography as a screening test, a diagnostic tool, an assessment tool, or even as an adjunct to mammography. There are no randomized controlled studies on thermography and, without proper clinical trials, the claims made by practitioners of thermography do not stand up to scrutiny. Yet, many Canadian women choose this procedure and some forego mammograms. These clinics are not part of the Canadian health care system and are in a grey zone of regulation. Unfortunately, there are no statistics to track the harm they may be doing.
Regulatory action in the United States
In the United States, the Food and Drug Administration (FDA) approved Class I telethermographic systems for the use of “adjunctive diagnostic screening for detection of breast cancer” in 1982. This means that thermography may be used only in conjunction with, not in place of, mammography for the screening and diagnosis of breast cancer. In recent years, though, the FDA has issued warning letters to companies that were inappropriately marketing and selling thermography devices and systems.
Regulatory action in Canada
Health Canada has not approved thermography for breast cancer screening either alone or as an adjunct to approved screening methods, and it issued a safety alert about thermography screening in 2012. At around that time, a thermography clinic in St. John’s, Newfoundland and Labrador was instructed by the province’s Health Minister to cease and desist for the reason that thermal imaging for breast cancer screening is unregulated in the province. Also, a thermography clinic in Winnipeg, Manitoba was directed by the provincial Health Minister to halt operations while health officials carry out an investigation.
A more recent Health Canada safety alert, issued in 2017, informs us that “[w]hile thermography devices are available in Canada, these devices have not been licensed in Canada to screen for breast cancer.” Thermography devices are licensed only for a very limited use as specialized thermometers. The safety alert also tells consumers that “…thermograms…are not a substitute for mammograms used for routine monitoring and screening for breast cancer” and that mammography “…is the most reliable technique in screening for early-stage breast cancer”. Health Canada asserts that it “…is not aware of any clinical evidence that thermography devices can be used effectively for the early detection of breast cancer” and cautions that “[i]f women are relying solely on thermography results, there is a potential risk that cancer could go undetected.” As a result, Health Canada restricted the sale of thermography equipment: “Health Canada is following up with several manufacturers to inform them that it is prohibited to advertise or sell thermography devices (such as cameras and imaging systems) to screen for breast cancer in Canada.”
The Canadian Cancer Society shares information and concerns similar to those of Health Canada. The Society concurs “…current evidence doesn’t show that thermography is an effective tool to detect breast cancer and therefore, we do not recommend thermography as a screening tool for breast cancer.” The Society adds that when private clinics advertise thermography as a reliable method of detecting breast cancer, it “…creates a confusing message for women” and that women who have been tested with thermography may have “…a false sense of security about their breast health”.
Use of breast thermography in Canada
Despite the lack of scientific evidence for the efficacy of thermography as a method of breast cancer detection, the lack of approval to use thermography for the purpose of breast cancer screening, and the prohibition on sales of thermography equipment, there are many businesses and private clinics in Canada that offer thermography service and devices for breast cancer screening. One such business is Thermography Clinic Inc., a Toronto-based company with thermography clinics established around the world. In Canada, Thermography Clinic Inc. has 22 clinics (including the head office) located across Alberta, British Columbia, Ontario, and Quebec. The company’s mission is “[t]o bring non-invasive imaging technology to the forefront of health care and to impact breast cancer statistics globally.” Thermography Clinic Inc.’s website characterizes the procedure as safe, pain-free, radiation-free, and non-invasive, all selling-points for potential customers considering this procedure.
Thermography Clinic Inc. sells “turn-key” thermography systems to existing clinics or new start-up businesses and supports them with system installation, personnel training, and results reporting. Practitioners who undergo just three days of training are provisionally certified by the College of Medical Thermography to write and interpret breast thermography reports for consumers.
A close inspection of Thermography Clinic Inc.’s website reveals some concerning points. The website appears to feature misleading information and unproven claims about thermography, such as:
To deny the efficacy and [sic] of thermal imaging of the breast as an adjunctive assessment in the overall management of the patient is a grave error.
We cannot ignore the tremendous role of breast thermography as an early risk indicator or as a monitor of treatment.
Furthermore, the technology appears to be advertised for unlicensed uses and unapproved purposes. The following statements are some examples from their brochure [PDF]:
Early Detection is important, but prevention is the key! [brochure title]
Breast Thermography is a breakthrough imaging procedure where infrared images of the breasts are analyzed and rated to determine the risk of developing breast cancer.
Breast Thermography is one of the best early-detection systems available today.
Conclusion: The exploitation of fear
Thermography clinics capitalize on the unjustified fears some women have that radiation doses from mammograms are dangerous and can be avoided by using thermography. The truth is that thermography is unproven and can burden women with false negative or false positives that can cause psychological stress, delayed treatment, unnecessary treatment, or worse, and charge a lot of money for the experience. In Canada, mammograms are free and they are the gold standard for breast cancer detection, so stay away from thermography.
Center for Inquiry Canada
The Centre for Inquiry Canada supports science-based medicine in Canada and advocates for empirically-supported medical interventions.