Scary, or not scary? I can't decide. But there's no doubt this new study from Canada is going to prod me to fulfill my New Year's resolution (don't ignore boring serious stuff) and make that mammography appointment.
The Canadian study, which compared eight years of mammography history from 1,112 women who'd had breast cancer with the histories of an equal number of women who had never had the disease, is getting serious attention because it offers evidence of an important new type of risk factor, and one that's more influential than some of the more commonly cited factors like family history. (According to the study, the only two factors more significant than tissue density are age and certain genetic factors.) All in all, the findings are pretty staggering: After controlling for other factors, women with density in more than 75 percent of their breasts experience five times the risk of developing breast cancer than those with less than 10 percent.
Like all breast cancer discoveries, I welcome this one with groping fingers and an anxious mind. What exactly is a dense breast, and how do you know if you have one? According to the researchers, density is defined as a higher percentage of milk ducts and connective tissue than fat. This fact makes me a little nervous, since when I was breast-feeding my kids, I was one of those prodigious producers -- I could have provided the diet for a small planet. (No real pride there, just a special empathy for dairy cows.) If anyone has an excess of milk ducts ... but enough baseless speculation. For better or for worse, mammograms are currently the best way to detect density.
There's long been a suspected link between breast density and cancer. But since both cancerous tumors and highly dense tissue show up lighter than fat on mammograms, some questioned whether the density constituted an actual risk factor or simply masked detection. The study suggests it's actually both. Women with dense breast tissue are more likely not to get diagnosed: In fact, Medpage Today reported that the "masking effect" of dense breast tissue increased the odds of a cancer being missed by more than 17 times.) But now that there's also evidence that density is a serious risk factor, some doctors are calling for a reevaluation of diagnostic protocol, including the possibility of screening women with dense tissue with other imaging techniques like digital mammography, ultrasonography and magnetic resonance imaging (MRI).
I say bring it on -- 'cause something ain't working. Last year I turned 42, and not one, not two, not three, but four women I knew got breast cancer -- and none had any of those risk factors we're told to watch out for: a family history, smoking, obesity, high fat intake, having kids after age 35 or having no kids at all. One of them had lumps that didn't show up on her mammogram. I know, I know: This is just the sort of testimony that adds nothing to the annals of science, but it's the tangle of lived experience that keeps me reading these studies for a glimmer in the forest.