Breast cancer – Seeing red

It’s a truism that our greatest anxieties are also our most vulnerable points. Having kids is the best example but somewhere in many people’s top 10 will be a lurking concern over cancer. And, human nature being what it is, you can be sure that another lurking hazard is those who would exploit our weaknesses for commercial gain. A recent article in one of the most prestigious cancer journals has highlighted an example that deserves wider publicity. At issue are the relative merits of two methods for the detection of breast cancer – mammography and thermography.

Mammogram of a normal breast. American College Of Radiology

Mammography

Breast cancer screening is currently a topic of some debate in the light of reports that such programmes may be of little or no cost benefit. The standard method is mammography: this uses low energy X-rays to obtain images of tissue within the breast from which abnormalities may be identified. As the controversy reflects, it’s not perfect. There’s a threshold size below which tumours can’t be detected, there are false positives (abnormal mammograms not due to cancer), tumours that are difficult to spot (because of high tissue density), abnormal growths that get picked up but are not life-threatening – and the subject is exposed to ionizing radiation which itself can promote cancers.

Breast thermogram

Thermography

Perhaps more helpfully called thermal imaging, this method detects infrared radiation, which increases with temperature so that warmer things stand out from cooler. In effect you get a surface heat map – in animals of skin temperature, which rises as blood flow increases. As growing tumours stimulate the growth of new blood vessels, they can show up in thermograms.

What’s the difference?

Well, it’s sensitivity. A number of studies have concluded that, although thermography is non-invasive and painless, it’s just not sensitive enough to be used as a routine screening test for breast cancer. The US Food and Drug administration (FDA) – responsible for protecting and promoting public health – has this to say: ‘…thermography is not a replacement for screening mammography and should not be used by itself to diagnose breast cancer. The FDA is not aware of any valid scientific data to show that thermographic devices, when used on their own, are an effective screening tool for any medical condition including the early detection of breast cancer or other breast disease’.

Why the fuss?

What upset the authors of the article is that direct-to-consumer advertising is presenting thermography as an effective breast cancer screening method on the basis of misleading information and that this may be damaging if it persuades women to forsake mammography, imperfect though that may be. ‘Misleading’ includes exaggerating the sensitivity of thermography, suggesting that having a mammogram could promote tumour spread (for which there is no evidence that I know of) and the claim that thermography is ‘FDA approved’ (no, you didn’t misread the last paragraph).

Bottom line

There’s a place for everything – except for deliberate misrepresentation: cancer’s too difficult and too important for that. And the gold standard for monitoring breast cancer remains the ‘triple test’: physical breast examination, imaging (mammogram, possibly supplemented with ultrasound and/or magnetic resonance imaging) and removal of cells for pathological examination.

References

Lovett, K.M. and Liang, B.A. (2011). Risks of online advertisement of direct-to-consumer thermography for breast cancer screening. Nature Reviews Cancer 11, 827-828.

Raftery, J. and Chorozoglou, M. (2011). Possible net harms of breast cancer screening: updated modelling of Forrest report. British Medical Journal 2011;343:d7627 

Food and Drug Administration (2011). FDA Safety Communication: Breast Cancer Screening – Thermography is Not an Alternative to Mammography [online]

Kontos, M., Wilson, R. & Fentiman, I. (2011). Digital infrared thermal imaging (DITI) of breast of breast lesions: sensitivity and specificity of detection of primary breast cancers. Clin. Radiol. 66, 536–539. 

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4 comments on “Breast cancer – Seeing red

  1. Hi Robin, I agree with a lot of the concerns you are raising in terms of incorrect marketing of the benefits of thermal imaging, as well as the way it works. However, I would like to point out that as an ADJUNCTIVE technology, which is what the FDA gave approval for, it’s an excellent tool. There is also a great deal of mis-conception that it can do the same thing as a mammogram, which is totally incorrect.

    They are two entirely different ways of monitoring the breast. simply put, a mammogram is looking for structural mass ( i.e; a tumour, or changes in the architecture of the breast tissue, microcalcification), and uses x-ray ( radiation ). A thermal image is using an infrared camera to capture a picture of heat generated from the breast, looking for asymetric patterns, that may represent abnormal vascular ( blood ) activitity. Research has established a well documented condition known as angiogenesis, that in it’s simplest form is a condition created by cancer cells releasing proteins to assist a tumour in recruiting localised blood supply, for more rapid growth, in the earliest stages. This increased blood supply generates heat, which from a thermal image point of view, may be a very clear indicator of potential for developing pathology. The real worth of infrared imaging is that this can detect activity, many years ahead of traditional methods, which require a tumour to be a certain size before it cam be observed. Early intervention strategies, implemented as a result of the alert from infrared imaging, may well change the long term outcome for the client. In summary, mamography measures structure of the breast, and thermography, function. Two very different ways of comparison, and one cannot replace the other.

    It distresses me enormously when I see the device incorrectly marketed by unscrupulous vendors, and I believe the entire industry requires some serious regulation and raising of standards.

    What I would hate to see however, is a knee jerk reaction that leads to a loss of availability of this amazing technology. What is really needed are long term. parallel clinical trials, correctly structured to accommodate the differences of the two technologies.

    I have used the device in my health & lifestyle consulting practice for the past five years now, in Australia, and it has been an extremely useful and definitive adjunctive tool, for the many women that either refuse mammography, or cannot use it. As you say, no technology is perfect, but using them in combination, gives far greater scope for managing breast health outcomes.

    There are many women who find a mammogram unsuitable, but still want to monitor breast health. Women who are breastfeeding and may find a lump ( usually hormonal but still needs to be investigated ); women with painful, engorged breasts from mastitis; cyclic tender breasts; exceptionally large or small breasts that are difficult to image with mammography; women with implants that are fearful of them bursting or have already experienced this from previous mammograms; women who have had breast cancer surgery with follow up chemotherapy and radiation and want no further exposure to x-ray and women who have had a mastectomy but still want to monitor the chest wall tissue. Mammography does not serve any of these women. And then of course the younger women, with family history of breast cancer, who technically, are unsuitable candidates for mammography, due to high breast density of younger women, which makes interpreting a mammogram far more difficult. By the time these women reach the age they are eligible for a free mammogram, (between 40 – 50) it’s not unusual for them to have had upwards of 20 – 40 mammograms !! Research from the Nordic Cochrane Data Center in 2009 and then again late last year, would indicate it may be sensible for a woman to limit the number of mammograms she has during her lifetime, due to a risk of accumulation of low dose radiation.

    Utilising a non-invasive approach such as infrared imaging, in conjunction with mammogram and ultrasound, only when considered necessary, may well be the way of the future.

    There are a multitude of women who risk being lost in a system that fails to recognise and accommodate their needs, and thermography definitely has something to offer them. I believe.

    • Patricia, thank you so much for taking the time to provide such detailed and authoritative comments on my thermography piece.

      I agree entirely with almost everything you say and your observations based on your own consultancy experience of where mammography is inappropriate were both interesting and very informative about an area that is beyond my expertise.

      Just to confirm or amplify a couple of points.

      You are, of course, quite correct in noting that thermography has FDA approval as an adjunctive method: I was careful in my piece only to refer to the recommendation regarding sole use, marketing on that basis being the cause for concern.

      I also explained that the information it gives is quite different to that obtained from a mammogram – albeit without the excellent detail of your comment – and noted that ideally mammography is combined with other detection modalities.

      We obviously both feel very strongly about unscrupulous marketing – which was what prompted my piece and the original Nature Reviews Cancer article. I suspect you may have had to deal with some of the consequences. I was just horrified on reading some of the web-site advertising – all that I’ve picked up being from American-based companies – in the way that they weighted, selected or invented evidence to promote their sales pitch. We know very well that this is by no means the first example of that kind of commercialism – perhaps we have to live with it as one face of capitalism – but at least those of us who are a little better informed can try to guide those attempting to make sense of it all.

      Your comment on the screening debate that I also mentioned only in passing is again spot on. Although I cited the latest review on this topic (can’t help it – I get so annoyed with so-called ‘science journalists’ who don’t quote their sources) I rather hope members of the general public won’t read it because its conclusions are sufficiently negative that I could see them promoting a move away from screening in the kind of reflexive reaction you mentioned. This risk might be further increased if people pick up on one or two recent surveys that have concluded, in effect, that screening is a waste of money. At least the Raftery analysis shows how difficult it is to assess benefit. Overall, I’m inclined to the view that breast screening has been beneficial, albeit only modestly so – and also to keep in mind that detection methods are slowly improving.

      I would just make one last comment to the effect that, although ultimately thermography is sensitive enough to detect enhanced vascular activity associated with growing tumours, I know of no evidence that it has been more effective at detecting early tumour growth than other methods. The detection of tumour growth at an early stage and of initial responses to drugs represent, of course, two of the current major cancer challenges. My own feeling is that none of the methods currently in clinical use are up to either of these tasks. Whether 13-carbon hyperpolarization, currently in early clinical trials, will provide a great leap forward remains to be seen – though to be sure it’s fascinating!

      Once again, thank you very much for your thought-provoking comments.

    • Wow! Thanks for pointing that out. Can’t believe that everyone doesn’t have one – the advertising seems to suggest it will improve pretty well anything. Wonder if it would work on my batting average. Think this is where we came in!!

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