For the past 15 years, the medical community has known the extent to which increased breast density  (i.e., dense breasts ) reduces the accuracy of the mammogram. Relatively simple additional testing (screening ultrasound) is available that could find large numbers of cancers that are missed on these false-negative mammograms. While this information is potentially of great importance to guide women’s breast health decisions, it is not being routinely transmitted from physician to patient. Therefore, women’s health advocacy groups have begun legislative efforts to mandate transmission of this supplemental  information. Three states— Connecticut, Texas, and Virginia—have already passed these “inform” laws. New York State is now considering similar legislation.

On May 1, WVFC’s Dr. Thomas Kolb addressed lawmakers in Albany, educating them about the absolute necessity of this legislation. Below is a slightly edited version of his remarks.

Simply put, for most women, breast density is the single most important indicator of future risk of developing breast cancer, as well the single most important reason that a mammogram, erroneously, fails to diagnose breast cancer. Yet in spite of its significance, the vast majority of women do not know their own breast density, nor have they been made aware of our ability as physicians to diagnose breast cancer by other means in the face of a falsely negative mammogram.

In 1998 and again in 2002 I published papers examining over 27,825 consecutive women and determined that in women with non-dense breasts, 98 percent of cancers are mammographically visible. Yet in those with the densest breasts, 60 percent of invasive breast cancer was mammographically occult or missed.

Yet we as radiologists report to physicians and patients alike only the result of their mammogram, regardless of influencing factors, knowing full well that if a woman has non-dense breasts we are 98 percent accurate, but if she has dense breasts, and were to have a breast cancer, we would only be 40 percent accurate in our diagnosis. Worse, by not detecting her breast cancer we allow it to grow until her next mammogram, or two or three, or until it becomes palpable, which translates to, at a minimum, double the size at which it could have been detected with imaging. This information is never directly transmitted to the patient.

Our studies also showed that adding screening ultrasounds increased the number of women diagnosed with invasive cancer by 42 percent—an enormous increase in cancer detection in a mixed but mostly normal risk population. This result was similar to findings in the recently published ACRIN trial, published in Journal of the American Medical Association this past April, which evaluated 2,662 high-risk women over three years.

It is a fact that screening mammograms are more effective in women 50 years of age and older than those 39 to 49.

There are two possible reasons for the lesser but still important benefit in younger women. First, younger women have denser breasts that obscure cancers. In fact, 66 percent of premenopausal women vs. 25 percent of postmenopausal women have dense breasts. Second, tumors in younger, premenopausal women are more often aggressive, or become more aggressive (de-differentiate) at a smaller size than in older, postmenopausal women.

Therefore, in order for us to do better at finding these tumors at an early, more treatable size, we must turn to adjunct screening with either breast ultrasound or MRI.

MRI is the single most effective screening means we have for detecting breast cancer. The ACRIN study reported a 56% absolute increase in cancer detection in high-risk women with dense breasts utilizing MRI vs 34% for ultrasound, beyond what mammography can detect.

However, MRI can never be used to routinely screen large populations of women: The examination requires 30 minutes to perform and an intravenous injection of contrast. It also costs 10 times more than breast ultrasound. Therefore, it is reserved for only the highest risk patients.

Ultrasound is a shorter procedure, requires no intravenous injection, and is substantially cheaper.  Its false-positive rate of 5 percent and true-positive biopsy rate of 10 percent is totally acceptable. On behalf of all women, I disagree  with those who believe otherwise. Patients do not. An ultrasound-guided biopsy is a very simple and quick needle aspiration procedure;  the alternative is missing an early breast cancer.

While there are no randomized controlled trials for either screening MRI or breast ultrasound, it is important to note that the American Cancer Society currently recommends routine annual screening MRI in the highest risk patients, with the assumption that finding cancers earlier will benefit these patients. There is no reason to believe that breast ultrasound would do otherwise.

At this time, even annual clinical examination of the breasts is universally recommended and reimbursed, with no proven benefit or efficacy and in spite of its substantial false positive rate. Clinical Breast Examination  finds 27 percent of cancers, and 60 percent are Stage 2 or worse. Breast ultrasound finds 85 percent, and 90 percent of those are Stage 1 or lower.

Though waiting for randomized controlled trials is optimal, it is somewhat disingenuous, and perhaps reckless, to suggest waiting,  since randomized controlled trials will likely never be performed, because of their cost and complexity—and even if done, it would take 10 to 15 years for survival data to become available. It is important that legislators in Albany support patient education, cancer detection, and ultimately patient survival in a somewhat stagnant (at best) or hostile (at worst) health care environment. Much higher rates of breast cancer can be detected with adjunct screening. To dismiss this by citing patient anxiety, false-positive rates, and cost is not the way to advocate for patient health.

Only with information about their own bodies will women have a meaningful understanding upon which to base their breast health care decisions.

Therefore, both information and insurance legislation should be passed. It is both morally and medically necessary. The time has come.

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  • Barbara Thornbrough June 28, 2013 at 1:17 pm

    Thanks for the work you are doing on this subject on behalf all of women.
    Excellent and informative article. BT