Thirty years ago, I limited my academic surgical practice to breast cancer, whereupon I made a strange observation. Granted, my experience was skewed by the referrals of younger women (with dense tissue) seeking Oklahoma’s only self-proclaimed, breast-dedicated surgeon at the time. Still, a large percentage of my newly diagnosed breast cancer patients had negative mammograms even though their tumors were palpable. At the same time, mammography was being widely promoted as having 90% sensitivity, although there was little or no distinction made as to whether the 90% applied to palpable or non-palpable cancers.
I became intrigued by the phenomenon of mammographically invisible breast cancer (few seemed to care at the time), and my first academic paper had nothing to do with surgery, but with these “invisible cancers.” (Establishing a Histologic Basis for False-Negative Mammograms. Am J Surg 1993; 166:643-647). For that paper, I reviewed the pathology of palpable, but mammographically invisible, cancers at the University of Oklahoma and found that nearly all had diffuse histology, ductal or lobular, that did not form a distinct mass. In preparing for publication of our findings, I had to write the introduction, which meant a literature search to get the ball rolling.
Unless you were publishing articles in the pre-Internet era, you can’t imagine the time it took to look up potential sources in the Index Medicus at the medical library, then manually retrieve each journal article by walking through the library, first finding the bound copies of the journal in question, then the article needed. On this particular question, I could not find the source of the oft-quoted 90% sensitivity for mammography. What appeared in my first breast cancer article was two weak references about mammographic sensitivity, just enough to get by. Many years would pass before I learned the shaky origins for the “90% sensitivity” for mammography.
But my interest was piqued. How do you know when you missed a cancer on mammography when there’s no way to double check? 12-month follow-up became the standard answer, but I found this problematic at many levels. Ultrasound was making its entrance around this time, but only to distinguish cyst from solid. Several more years would pass before benign vs. malignant became possible. MRI was still a decade away, though Dr. Steve Harms was offering audiences at nearly every breast conference an advanced look at his images obtained using his RODEO MRI.™ In case after case, he showed us pictures and narrated: “Here’s the cancer on MRI; here’s the negative mammogram.” My faith in mammographic sensitivity fell even further.
In essence, I took up a “hobby” in the form of reading everything I could about mammographic sensitivity. Over time, it became more of an obsession as I gradually put the pieces together and realized that sensitivity of screening mammography (non-palpable cancers) had been wildly overstated, most notably in women with dense breasts. At the time, few were paying attention to the dense breast issue, and my 35mm slide presentations and later Powerpoint, always included the joking reference to Rodney Dangerfield, in that breast density was simply “not getting any respect,” despite its major implications with regard to sensitivity (and secondarily, risk).
This gradual understanding of true mammographic sensitivity altered the course of my career, as I left breast surgery when breast MRI became commercially available (2003) and became a quasi-pseudo breast radiologist (“theory of…” as opposed to interpretations), focused on studying the benefits of supplemental imaging with ultrasound and/or MRI (with other methodologies in the works).
Resistance to multi-modality imaging has been powerful. And one of the primary reasons that supplemental imaging of any type is met with resistance is the false idol of mammographic sensitivity. Shortly after the introduction of MRI, Dr. Harms led CME efforts around the country, and he asked me to serve as the token surgeon where I warmed up the audience with my “90% thing,” (including Rodney Dangerfield) where I systematically destroyed the false belief that mammograms have strong sensitivity.
It’s a hard pill for radiologists to swallow, as they’ve been touting 90% for nearly 40 years. But they are caught in a bind now that we have multiple imaging methods that find double or triple the number of cancers found on mammography, rendering the 90% sensitivity for mammography impossible (except in Level A density patients). But once one admits to the deficiencies of mammography, especially in the dense breast, a whole new world of possibilities opens up with currently available imaging methods, as well as new technologies on the horizon.
So now, returning 26 years later to the same journal (Am J Surg) where I got my start on this singular question…here’s my Magnum Opus as presented via the Breast Care Network web site (where there’s another link to the actual article):