Thermography versus mammographyby Joanne Black
Practitioners of breast thermography say a hostile environment created by health authorities has jeopardised a useful service for women.
Instead of buying her three daughters a present this Christmas, Bobbie Gillespie intends to give them money towards the cost of their first thermograms. After becoming concerned about the radiation associated with mammograms, Gillespie, 67, had a thermogram a few weeks ago and is now a convert. She describes the process, in which an infrared picture is taken of the breasts, looking for unusual heat patterns, as “very simple, very easy and very, very non-invasive”.
Because of a “rather unpleasant” family history of breast cancer, the Katikati woman reads what she can about preventing and detecting the disease. Although she has never found a mammogram painful, “I just didn’t like having that amount of radiation zapped into me every two years”. She has had several lumps in her breasts, the first when she was 47, but says they were all detected by her, not by mammograms.
Gillespie’s sister has lost both breasts to cancer and has been living with the disease for many years. Gillespie says her sister’s cancer was detected by mammogram, but possibly later than it should have been. “My sister certainly should have been called back, because when she had a second mammogram three years later, one breast had cancer in it and the other had calcification. And when they looked at the previous mammograms, they could see that there was calcification in that breast and it was never investigated, which is why she had to have both off at once.” On top of that, a comment by a specialist attending to Gillespie’s husband, who has emphysema, stuck in her mind. Her husband required a chest x-ray soon after a previous one, “and the specialist said, ‘I really don’t want to do another x-ray because you know, don’t you, that x-rays cause cancer?’ So the more x-rays you have the more chance you have of getting cancer.
“So I had already decided to look at something different when my appointment for my mammogram arrived the other week and I thought, ‘I’m not going to do it.’” Instead, she made some calls and found out she could have a thermogram in Tauranga. “I went and had it done and I’m very happy. I have already dished out pamphlets to two of my friends and am sending them off to my daughters, too, and instead of giving them a Christmas present I’m going to give them some money towards their first one.”
Gillespie’s preference for thermograms over mammograms is an example of the choice that causes disquiet among radiologists. Many believe that women are often not well enough informed before they make decisions. The chairman of the New Zealand branch of the Royal Australian and New Zealand College of Radiologists, Mike Baker, has grave concerns. Statistically, he says, women who do not have mammograms are at far more risk of dying from breast cancer than they would be of getting cancer from being exposed to a low level of radiation by having a mammogram every two years.
Concerns by radiologists and the Cancer Society about the increased use of thermography led to what was effectively a campaign against it. That in turn appears to have contributed to the company Clinical Thermography going into liquidation earlier this year, with the company’s lawyers claiming health authorities had deliberately painted thermography as not only useless but also dangerous.
In particular, a position statement on thermography, jointly released in June last year by the National Screening Unit, the Cancer Society, the Breast Cancer Foundation and the Royal Australian and New Zealand College of Radiologists, was damning. It said the four bodies “do not support the use of thermography for breast cancer screening or as a diagnostic tool to detect breast cancer as there is insufficient evidence to do so. If thermography is offered to women for breast assessment, it is vital that women are fully informed of the potential harms of thermography, including the likelihood of false positive results and false negative results, and typical annual costs. This information should include an acknowledgement of the lack of proof of efficacy and effectiveness of breast thermography as a screening and diagnostic tool.”
But Jamie Newman, who was involved in marketing for Clinical Thermography but who no longer represents the company, says the company did not promote thermography as a screening and diagnostic tool, or as a rival or replacement for mammography. “We were very clear about that all the way through on all the reports. Our brochure says this doesn’t replace mammography – it’s an additional test that’s looking at breast-cancer risk and the physiology of breast tissue.” But if thermography is not used to detect possible breast cancer, what use is it? At $199 a session, why would any woman bother?
Thermography, which is radiation-free, uses an infrared camera to take a thermal image of a woman’s breasts, effectively providing a heat map of the surface of the skin, with the pictures then being read for any signs of abnormal blood vessels. Because a tumour requires its own nutrients and blood supply to grow, the theory is that any tumour present will emit more heat than the unaffected tissue around it, and therefore show up on a thermogram. Newman says thermal patterns in breasts remain remarkably stable over time. “So, much like mole mapping, a baseline thermogram can serve as something to compare future thermograms against. You can see a deterioration or improvement in that thermal signature, which is where the crux of thermography lies.
“When using it for risk assessment and breast-health monitoring, you have an opportunity to look at any lifestyle factors that may be contributing to the problem and you can use thermography to monitor an improvement or deterioration in health.” He says a number of Clinical Thermography patients who had a thermogram “had a bit of a scare”, so stopped smoking, or increased their exercise level and improved their diets, and thereby improved their thermograms over six to 12 months.
“So that’s the benefit – it’s more of a health-promotion tool than a disease-location tool. Thermography is looking for physiological irregularities, whereas mammography is looking for an anatomical irregularity.” Thermography advocates say because tumours have to be a certain size to be detected by mammogram, they can sometimes show up on a thermogram at an earlier stage. It’s also possible for tumours to show up on a mammogram but not on a thermogram, or for them not to show up on either.
“But we were very careful not to diagnose any problems and we never said it was a diagnostic procedure,” Newman says. “If we detected abnormalities, we recommended a structural test like a mammogram or ultrasound to look at the anatomy of the tissue.”
Gillespie says when she went for her recent thermogram, staff told her that if the result indicated it was necessary, they would recommend she go for further investigation, which might include a mammogram. However, she told the Listener she was unaware of the statistics that showed that having a regular mammogram, followed by recommended treatment if required, was the best way to reduce the risk of dying from breast cancer.
Newman says despite the company’s caution about what it did and did not claim for thermography, the medical community was most influenced by the Ministry of Health and the Breast Cancer Foundation. “And they were obviously very anti thermography right from the get-go, so it was, and still is, very difficult for medical practitioners to get accurate information about thermography as a breast-cancer risk indicator.”
Dr Mike Godfrey, who largely pioneered thermography in New Zealand and who later acted as a consultant to Clinical Thermography, says plenty of published literature in peer-reviewed medical journals shows the procedure has clinical value, particularly for younger women with dense breasts, on whom mammography usually does not work as well as it does on post-menopausal women.
He says he has seen the benefits in his own patients: thermograms have shown up areas of concern where mammograms have given no such indication, but subsequent tests have shown there is cancer. Thermography is not a substitute for mammography, he says, but if the two are used together, using the best equipment and the right protocols, the detection rate can reach 95-97% “which is as good as you can get”.
Thermography is approved by the US Food & Drug Administration as an “adjunctive” breast-screening tool, meaning it is approved to be used in addition to mammography. Increasingly, he says, overseas radiologists also have thermal-imaging cameras in their clinics. Godfrey, a retired GP living in the Bay of Plenty, is no stranger to challenging the accepted wisdom of the medical establishment. He is a member of the group Physicians and Scientists for Global Responsibility and has publicly suggested the dangers of mass vaccinations in childhood have been underplayed. He says he became involved with thermography when a 35-year-old patient, the daughter of another of his patients, went to Brisbane for a thermogram because she did not want to have mammogram.
“She came back with these pictures and said, ‘Hey, Mike, this is what you should be doing.’ I thought it looked interesting, and got involved.” Not long after he had two patients who had thermograms indicating a problem. He referred them both for mammography. “One came back and the radiologist said there was absolutely nothing there, don’t worry, thermal imaging is unscientific, etc. The woman came back to me nearly a year later, even though I’d told her to come back after three months, and the breast was a lot worse.” Godfrey says he went with the woman to the radiologist, “they did another mammogram and said, ‘There’s nothing there.’”
Godfrey was so sure there was a problem that he said he would send his infrared cameras back to the US and try to get his money back on them if it turned out the patient had nothing wrong. “She was sent for an MRI scan, which revealed an 8mm tumour – invasive breast cancer.” That case and another – in which invasive breast cancer was discovered after a lumpectomy, but which had shown nothing on a mammogram – persuaded Godfrey of the value of thermography.
“I got my two nurses trained up and we gradually developed a system where they were going around the country to different cities, spending up to a week every three months doing thermal imaging.” When he discovered the Newman family had started up the Clinical Thermography business in Remuera, he got in contact and in due course was a consultant to that company.
“However, I think they spent too much on promotion and marketing, not realising that BreastScreen Aotearoa and that group had made certain that every GP in the country was given information to tell them that thermal imaging was total rubbish. That means patients who trusted their GP would go along and say, ‘What about thermography?’, and the GP would show them the handout and say, ‘Look, this is useless.’ So even before the position statement came out last September, Clinical Thermography was in dire straits financially – the position statement and publicity in Next magazine and other places was the final straw, and they went into receivership.”
Godfrey has formed another thermography company but is now waiting to see what the National Screening Advisory Committee (NSAC) ends up doing. The position statement is being reviewed, but a lawyer acting for Clinical Thermography, Stephen Franks, has written to the ministry saying his clients “no longer have confidence in the integrity of the ministry” and are expecting “a whitewash”. And in a letter to National Health Board national director Chai Chuah, Franks wrote: “It is clear the terms of reference have been cunningly contrived to answer a narrow question on which our clients agreed the answer a year ago, and not to ask the questions that might embarrass the [National Screening Unit].”
In an earlier letter to Franks this year, Chuah said the review would be an investigation about whether the position statement was fair, accurate and based on appropriate evidence. Chuah declined to be interviewed until the review is complete. In the meantime, Godfrey says, he is in limbo. “We can’t do anything significant about investing time, money and effort into establishing our clinics until we at least get some credibility from the NSAC. I don’t expect the Ministry of Health is going to say, ‘Hey, welcome, this is a real advance.’ But all we want is sufficient recognition that thermal imagining has the potential to improve diagnosis, that it has a definite role for women under 50 and for women with dense breasts. And let’s face it, 500 women under the age of 50 get breast cancer every year in this country and they’re basically being left in the lurch.”
He says the current situation is very disappointing. “It’s a real shame that the radiologists have taken this position, which is unwarranted.” He points out that although thermography does not diagnose breast cancer, neither does mammography. Further tests have to be done to determine whether any suspicious growth is actually cancerous.
Mammography itself has been coming under increasing scrutiny. A 2009 report in the British Medical Journal says breast screening would probably never have started if we knew then what we know now. And a large study of Norwegian women, published in the New England Journal of Medicine last year, suggests increased survival rates from breast cancer have more to do with improvements in treatment than with mammography itself.
However, regular mammography remains, at present, the single best means of reducing the risk of dying from breast cancer, because although having a mammogram does not stop a woman developing the disease, it increases the chance that it will be picked up early if it is present. BreastScreen Aotearoa says for women under 50, regular screening reduces the chance of dying from breast cancer by about 20%. For women between 50 and 65, screening reduces the chance by about 30%, and for women aged 65-69, by 45%. Under the BreastScreen Aotearoa programme a free mammogram is available every two years to women aged 45-69. Outside the programme, a screening mammogram usually costs about $150, a bit less than the $200 for a thermogram.
Mike Baker says although having a thermogram is not harmful, what is a concern is women’s expectations about what they are getting from the process, and in particular the comfort they might take from a negative result. He concedes a mammogram can also give a false negative result, but says “mammography has full, published figures and huge studies – it must be the most studied screening procedure in the world. There are recognised failings for mammography but it is a very good screening tool overall.”
Baker says his specialty is diagnostic imaging, including ultrasound and MRI. If thermography was a recognised tool, he would use that, too, “but it actually doesn’t stack up and it never has done. We keep a watching brief on what’s coming through the literature but there’s nothing new. I know of no radiology practice anywhere in the world that supports the use of thermography.”
Cancer Society screening and early detection adviser Sarah Penno says the society believes women need to be fully informed about the possible benefits and potential harms associated with thermography.
“There isn’t clear evidence around its effectiveness, and despite what the [thermography] companies say, they have changed the information they had on their website to a much more balanced approach. When we started looking at this issue there was evidence of them making claims around screening, and so we achieved what we wanted, which was to get them to change the way they were presenting their information.
“Women were not being given good, balanced information to make informed choices as to whether or not to use thermography. At the end of the day it’s a person’s choice as to whether they use any of these kind of interventions. But there is no clear evidence that thermography has any long-term benefit or that it improves outcomes as far as breast cancer is concerned.”
Penno says the fundamental question is: will using this technology improve the outcome if I am diagnosed with breast cancer? “And the answer is no – it won’t. But if women choose to use thermography, they need to be clear about what it can and cannot do. To me, that’s where we were coming from with the position statement.”
She says she is not trying to have thermography providers “driven out of the country … People have a choice … but they have the right to be given information about whatever it is they’re doing, and whether it has harms or benefits associated with it and whether there is evidence of its effectiveness, and whether people are making false claims in their advertising.”
Breast surgeon Dr Belinda Scott, a board member of the Breast Cancer Foundation, also says she has no objection to women using thermography so long as they understand there is insufficient scientific evidence to support it as a screening tool. “[Thermography companies] were using it as a screening tool but they’ve changed quite a bit what they say about it, which is wonderful. The danger for women was in thinking they could go along, have this done and that’s all they needed. It’s the same with mammograms. Mammograms miss 10% of cancers. So what you have to do is use it in context.
“But if women want to have a thermogram, good on them. I think that’s a fantastic thing for them to do, but they need to understand that there is no evidence behind it … whereas there is excellent evidence behind mammograms to say it will pick cancer up early enough to save their life. That’s the difference for me.”
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