Two studies published this year raise additional and serious challenges – that’s putting it mildly – to the common wisdom (sic) of annual mammograms for women of any age. The US Preventive Services Task Force shocked the world in 2009 by suggesting less routine screening mammograms: none until the age of 50, and then only every two years. I agreed with the findings, though believe some of the critiques posed questions not fully answered by the Task Force. Now I believe those questions have been answered by 2012 reports.
The first study reported on outcomes of routine mammography offered to all women in Norway from 1986 to 2005. Comparing different counties within Norway as mammography was gradually introduced found no advantage to women in counties with earlier introduction of mammography. The findings indicated that 15-25% of breast cancer found through routine mammography would likely never have caused a problem. No problem found, none treated, and no life ruined with a diagnosis of breast cancer. No long-lasting ill effects.
Critiques of that study could claim “primitive” (over 10 years old) mammography or interference from a period of hormone replacement therapy. Supporters could argue that this study didn’t even include diagnoses of ductal carcinoma in situ, the most commonly diagnosed cancer and the one most likely to be utterly insignificant when it comes to life quality or length. Insignificant, that is, until and unless you trap it within a diagnosis: once diagnosed, ductal carcinoma in situ is treated like an invasive carcinoma with surgery, chemotherapy and radiation in some mix, depending on local medical advice and patient details.
The second study is truly much more damning and will hopefully be more influential. The concerns of the study are well stated early in this article (emphasis mine): “Screening to lower cancer mortality should enable earlier detection of malignancies destined to be fatal while also facilitating early treatment of screen-detected cancers.” There is no question that treatment of advanced cancer has improved over the last twenty years. There is however a serious question as to whether early stage cancer would inevitably progress to advanced cancer, or whether it would remain clinically insignificant.
If consistent screening truly identifies advanced cancer at an early stage, one would expect early stage diagnoses to increase (they have!) and late stage diagnoses to decrease – but they haven’t! Meaning that the women subjected to annual mammograms and diagnosed with non-invasive cancers are undergoing hefty medical treatments, at significant financial and emotional costs, for cancers that were never going to be serious anyway. We are good at treating serious cancers, we are seriously bad in our over-treatment of mammogram detected early or pre-cancerous lesions.
Looking ahead, there is the possibility of genetic analysis of breast tumors at any stage which will help determine: is this cancer going somewhere or will it just fade away. We’re not there yet, so where are we now?
What does this all mean? I suggest it means that there may be, more radically than the Task Force suggested, no indication for screening mammography at all. Yes to mammograms for abnormal physical findings. Yes to thermograms, which are indirect tests of hormone physiology as it occurs in the breast and which is instrumental in the development of some cancers. No more routine mammograms. What do you think of that?