Utter the word thermography in a roomful of breast specialists and you’re likely to set sparks flying. Some doctors say that this imaging technique can detect breast cancer sooner and more safely than mammography—but others dismiss the test as unproven and even potentially dangerous because it sometimes is misused.
The FDA, for its part, approved thermography nearly three decades ago as an adjunctive tool to screen for breast cancer. But recently, it warned women against using thermography as a substitute for mammography, saying it was “unaware of any valid scientific evidence showing that thermography, when used alone, is effective in screening for breast cancer.”
I contacted integrative cancer therapy expert Nooshin K. Darvish, ND, a former Bastyr University faculty member and medical director of Holistique Medical Center in Bellevue, Washington, to discuss this controversial issue. She explained that thermography uses an infrared camera to detect variations in body heat. It is based on the idea that diseased tissues—including infected, inflamed, precancerous and cancerous areas—produce increases in metabolic activity, blood vessel formation and blood flow that, in turn, increase temperature. Thus, these areas appear as “hot spots” on infrared images. Proponents say that the technique’s benefits include…
Early detection. Thermography can spot areas of abnormal heat before they show up on conventional tests. “Whereas mammography, ultrasound, CT and MRI are used to identify cancer after the tumor has formed, thermography can identify the first thermal and chemical changes that may lead to cancer prior to the existence of a tumor,” said Dr. Darvish. This may provide opportunities for early intervention to reverse the abnormality.
Effectiveness. In a small study published in The American Journal of Surgery, thermography accurately identified 58 out of 60 breast malignancies (as confirmed by biopsy) among 92 patients—an accuracy rate of 97%. Comparison: According to the National Cancer Institute, screening mammograms miss up to 20% of breast cancers that are present at the time of screening. Inaccurate results occur more often among younger women and those with dense breasts.
Safety. Unlike mammography, which uses X-rays, an infrared thermography camera emits no harmful radiation.
Comfort. Thermography is noninvasive and does not require painful breast compression. However, you do have to spend time in a cold room.
All this sounds encouraging. So why would this test bring doctors nearly to blows? Several reasons…
- Since the technology was first FDA-approved in 1982, there have been advances in infrared camera quality, computer technology and standards for training thermographers, Dr. Darvish said. However, while some small studies (such as the one cited above) reflect these improvements, there is an admitted shortage of recent large-scale studies on thermography.
- Many European doctors are clinically trained to use, and do use, thermography as an adjunct to mammograms, Dr. Darvish said. But, in the US, medical doctors generally are not trained in or experienced with thermography and often dismiss its value.
- Some conventional doctors complain that thermography has too high a rate of false-positive results. Thermography proponents argue that many supposed false positives actually indicate precancerous conditions that won’t show up on mammograms for years and should be “watched.” What’s more, mammography also is prone to false positives—a study in Annals of Internal Medicine concluded that 61% of women who get annual mammograms starting at age 40 are recalled for additional testing due to false-positive results by the time they reach age 50.
- Some thermography clinics promote the test as a substitute for mammography. This potentially dangerous misrepresentation leaves some doctors leery of thermography as a whole… and has prompted the FDA to issue warnings to clinics that violate its regulation classifying thermography as an adjunct rather than an alternative to mammography. Most thermographers, however, agree with the FDA that the technique is best used in addition to conventional tests. Reasons: While thermography can identify general areas of abnormality, it cannot pinpoint an exact area of suspicion the way mammography and ultrasound can… “cold” tumors (ones with low metabolic activity) are difficult to identify on thermal images… and no screening test can actually diagnose breast cancer—for that, a biopsy is needed.
WHO CAN BENEFIT
According to Dr. Darvish, all women can benefit from thermography. The test is thought to be particularly useful for those who…
Are premenopausal. Younger women generally have denser breasts, so mammograms are less accurate in detecting premenopausal breast cancers—yet these cancers are potentially the deadliest because they tend to grow fastest, Dr. Darvish said. She recommended that women get breast thermograms every two years from age 19 to 30 and yearly thereafter.
Have a family history of breast cancer and/or carry the BRCA gene. Thermography provides an extra layer of precaution for such high-risk women. Dr. Darvish has several patients who’ve had negative mammograms but whose thermograms found abnormalities that turned out to be cancer.
Have breast traits that make mammography less accurate. Mammograms are likelier to miss masses in breasts that are large, dense, fibrocystic or have implants.
Use hormone replacement therapy or birth control pills. These medications may increase breast cancer risk. Thermography helps monitor the safety of hormone use, Dr. Darvish said.
Are undergoing breast cancer treatment. A patient’s response to therapy can be safely assessed with thermography.
A breast thermogram costs about $280, which most insurance policies do not cover. For the most accurate test results: Use a physician-supervised facility whose images are read by a doctor certified by the International Academy of Clinical Thermology (www.iact-org.org) or the American Academy of Thermology (www.AmericanAcademyOfThermology.org). Testing procedure: You remove your shirt and bra and sit in a cool room for about 15 minutes while your body adjusts to the ambient temperature. Then you hold your arms in varying positions while pictures of your breasts are taken from different angles, which takes five to 10 minutes. Images are sent to the interpreting doctor. If suspicious areas are identified, a follow-up appointment is made to discuss the best course of action.
Bottom line: If you decide in favor of breast thermography, remember that it is best used as a complementary screening tool along with mammography. According to Dr. Darvish, sensitivity for early detection of breast cancer increases to approximately 95% when thermography and mammography are used together.