The answer is simple. Mammography is an imperfect test. A "normal mammogram" report does not mean that a woman does not have breast cancer. Overall, mammograms will pick up 80 to 90 percent of cancers. That's pretty good, but there are still 10 to 20 percent of cancers that will not be seen, and will present as an "interval cancer" with a palpable lump, as in the example above.
The cancer detection rate plummets in women with dense breasts to only 40 to 50 percent of cancers picked up on a mammogram. That's about the odds of a coin toss. This is ineffective screening by anyone's standards.
So what is a woman over 40 to do? Find out your breast density. If you have dense breasts, you need to be especially proactive to make sure that if you do have breast cancer, you increase the odds of it being found early. Ask your doctor to send you for a screening breast ultrasound (sonogram) when you have your annual mammogram (and go to a facility that has digital mammograms).
The findings from a recent large multi-center study (ACRIN 6666) are clear:
- 7.6 cancers were found per 1,000 women who had a mammogram only.
- 11.8 cancers were found per 1,000 women who had a mammogram and a screening sonogram.
This equates to a 29 percent absolute increase in sensitivity by adding a screening sonogram, or an increase in the relative cancer detection rate of approximately 50 percent.
Critics would argue that something might be found on the sonogram that requires a needle biopsy, and turns out not to be cancer (false positive). In my experience, most women accept the low (five percent) risk of possibly having a benign needle biopsy, and don't subscribe to the "don't ask, don't tell" policy when it comes to their breasts. Do yourself a favor and insist on that sonogram. Don't take no for an answer from either your doctor or from a radiology center that tells you they don't do screening sonograms. Seek a second opinion from another doctor. Find a radiology practice that is proactive about breast cancer screening. It's worth your time and effort.
I've seen a few patients recently who have been turned away by other practices in New Jersey that won't perform screening breast ultrasounds, even though their doctor wrote them a prescription for one. Truly unbelievable, but unfortunately true. Perhaps these practices are unaware that a bill has been proposed in the New Jersey state legislature, which requires that women be informed of their breast density when they have a mammogram. Connecticut and Texas have passed similar bills, and the radiology practices in these states have had to accommodate the increased demand for breast ultrasounds. Bills are pending in 11 additional states, as well as at the federal level. Practices need to plan for the increased volume as women and their doctors become more aware of this important issue.
Image: Stacey Vitiello.