From the Breast Diaries:

The Myth of the Negative Mammogram

It is a scenario familiar to all breast imaging practices.

A patient feels a lump in her breast and calls her doctor.  The doctor examines her, agrees that a lump is present, and refers the patient to a breast imaging facility for a diagnostic mammogram and breast ultrasound (also known as a sonogram).  At her mammogram appointment, a little sticker is placed on the lump felt by the patient, and mammogram images are taken.  Something may or may not be seen on the mammogram at the site of the lump.  A breast sonogram is performed, and a suspicious mass is seen, clear as day.  And sometimes it’s not so tiny.  The yellow arrow in the sonogram image below demonstrates one such mass:

sonogram image

The radiologist assigned to read mammograms that day tells the patient that a mass has been found, and she needs to have a needle biopsy.  The biopsy is performed, cancer is diagnosed, and when the patient is given this news she exclaims, “But how can I possibly have cancer?  I just had a normal mammogram a few months ago!”  Everyone is upset.  The radiologist who read that “normal” mammogram a few months back (sometimes it’s only a few days or weeks before) frantically pulls up those films to see if he/she missed the cancer.  Very often there was nothing on the mammogram that would have raised suspicion, yet there must have been something there since the patient now comes in a short time later with a palpable lump.  How did this happen?

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 80-90% of cancers.  That’s pretty good, but there are still 10-20% 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 40-50% 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 multicenter study (ACRIN 6666) are clear:

  • 7.6 cancers were found per 1000 women who had a mammogram only
  • 11.8 cancers were found per 1000 women who had a mammogram and a screening sonogram

This equates to a 29% absolute increase in sensitivity by adding a screening sonogram, or an increase in the relative cancer detection rate of 50%!

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 (5%) 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 ultrasound, 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 NJ 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.  (If you are at high risk for breast cancer, a breast MRI might be the better test for you; ask your doctor about this, and see “How Do I Know If I’m High Risk?”)

Be your own advocate!  Your life is too important, and you only get one.

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  • Denseca

    Thank you Dr. Vitiello for sharing this life-saving information for women with dense breast tissue!

    • Stacey Vitiello

      My pleasure! Glad you found it helpful.

    • Anonymous

      You are most welcome. Glad you found it useful!

  • Teresa Masters

    This is almost my story. Only SonoCine found my cancer. My “world class” imaging center was watching two clean areas. It was only after I brought them the second opinion did they go digging with two extractive core biopsies, and an MRI, did they eleven days later call me to say “you have cancer.” Duh, thanks.
    I was offended when Governor Jerry Brown of California refused to sigh the Dense Breast Notification bill into law. His reasons were typical of some men towards “don’t scare the poor lass,” Animal excrement!

    • Stacey Vitiello

      There’s also the issue of health insurers not wanting to pay for an ultrasound or MRI for women with dense breasts, and lobbying the governor.
      I’m glad your cancer was finally found (hopefully early). Thanks for commenting, Teresa!

    • Anonymous

      I’m glad to hear that your cancer was finally found, hopefully early. I was disappointed with the California veto as well. Thank you for commenting!

  • Pingback: The Myth of the Negative Mammogram « Stacey Vitiello, M.D. #mammography #Radiology #imaging | Peacefield Radiology

  • Ramslovelace

    The stories are countless. How many more women have to find out that their mammogram did not show the cancer that was there, before it becomes a law that all women are told their breast density when they have a mammogram. The doctor’s always see the breast density because it is generated when you have a mammogram. Years in the future, people will ask why it had to become a law before women find out what their breast density is. A lot of women will die because our society will not do what just makes sense.

    • Anonymous

      I’m hoping this situation will change in the near future, helped along by grassroots support! Thanks for commenting.

  • jennyct

    I live in CT and I have been refused a screening ultrasound from Jefferson radiology TWICE. After some worry about calcifications in the R breast, I received a diagnostic… but my left breast was ignored. I now have pain in the left breast and am very upset that it has been ignored.

  • Ajloves2run

    I had mammo and ultrasound and doctor from both tests said lumps were b9 but calcification was suspicious. Turns our I had invasive ductal carcinoma with Her2 positive. I was 37 when I found lumps. Doctors I saw said lumps “felt” B9. Boy were they wrong.

  • tjtots

    I went for my annual mamo two weeks ago and was asked to come back for a diag mamo and possible ultrasound this week. My screening results were: There are scattered fibroglandular elements in both breasts that could obscure a lesion on mammography. There is a 7 mm focal asymmetry with an indistinct margin in the left breast at 8 o’clock middle depth.
    I went back for my diag mamo and they didn’t even do the ultrasound and had an assistant walk me to a waiting room and tell me “everything was fine and come back next year.” The result I got by looking online was: No significant masses, calcifications, or other findings are seen in the breast. There has been no significant interval change. BI-RADS CATEGORY 1: NEGATIVE
    There is no mammographic evidence of malignancy. A 1 year screening mammogram is recommended.

    I am obviously disappointed that they didn’t even do a consult or advise me personally of the findings. Even after asking the young girl what did they say it was, I was given no information other than, it’s benign.

    I’m wondering if I should insist on an ultrasound or ask for a second opinion?? What’s your thoughts??

  • amy williams

    Hi i am 32 yrs and my sister got breast cancer when she was 42 yrs at my regular exam dr found a 2in thicking sent me get mammo and ultrasound they said they seen nothing so said was tissue, that was 5mos ago and its still there im worried and wondering how long it will be there…will it be there for along time? I feel stupid for asking because when i asked they looked at me stupid and said they didnt know. Should i be worried or just relax and its normal. They also said i was young to have any worrring lumps even though they knew my sister had cancer..thanks for help