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Posts Tagged ‘missing breast cancer at mamography’


There are 40 million women seeking mammography breast-screening every year in the USA, out of which 15 million are women with heterogeneously dense or extremely dense breasts. USA epidemiology statistics show that 6 out of 7 missed cancers at mammography occur in women with dense breasts. It is also known that the majority of women presenting with mammography-dense breasts are below 45 years old.

The Oct. 22 issue of the American Journal of Roentgenology ( AJR) publishes results of a study showing that ultrasound is superior to mammography in evaluating symptomatic women 30-39 years of age [1].

This study was conducted by researchers at the Seattle Cancer Alliance and University of Washington. Patients were recruited between January 2002 and August 2006.   954 women ranging from 30 to 39 years old who presented for diagnostic breast imaging evaluation were  examined, and it was found that sensitivity (probability for cancer detection) of ultrasound was 95.7 percent compared to 60.9 percent for mammography. A very important result of this study is the calculated Negative Predictive Value (the probability to have negative pathology if the imaging-test is negative) which was similar for both modalities: 99.9% for ultrasound and 99.2% for mammography.

Show case in images (All images courtesy of the American Roentgen Ray Society.):

35-year-old woman who presented with a palpable left breast lump. Whole-breast craniocaudal (above left) and mediolateral oblique (above right) and spot-magnification craniocaudal (below left) and mediolateral (below right) mammographic images show no abnormality at area of clinical concern, marked by BB.

Zoom-in on the region of interest

Targeted ultrasound image above reveals solid mass with irregular shape and indistinct and angular margins. BI-RADS 5 assessment was made. Histopathology from ultrasound-guided core needle biopsy showed invasive ductal carcinoma.

In regards to which imaging modality should be used when screening such a population, the conclusion of the investigators is very clear: “Ultrasound has high sensitivity (95.7%) and high NPV (99.9%) in this setting and should be the primary imaging modality of choice. The added value of adjunct mammography is low.”

When reading this article I noted a gap to overcome if we want to successfully replace mammography with ultrasound. The Positive Predictive Value (the probability of  detecting a cancer) calculated for ultrasound in these study settings was lower than that calculated for mammography: 13.2% for ultrasound and 18.4% for mammography. This is because mammography detected one additional malignancy in an asymptomatic area in a 32-year-old woman who was subsequently found to have a BRCA2 gene mutation. Mammography could do that because it scans the whole breast, whereas the investigators in this study used ultrasound just for scanning the suspicious lumps. A solution is offered in using the recently introduced ultrasound modalities, which are able to perform automatic full breast ultrasound scans [2], preferably enhanced by real-time tissue characterisation capability – a technology I’m working to develop.

References:

  1. Accuracy and Value of Breast Ultrasound for Primary Imaging Evaluation of Symptomatic Women 30-39 Years of Age,Constance D. Lehman1,2Christoph I. Lee1,2Vilert A. Loving1,2, Michael S. Portillo1,2Sue Peacock1,2 and Wendy B. DeMartini1,2, Oct. 22 issue of the American Journal of Roentgenology
1 Department of Radiology, University of Washington School of Medicine, Seattle WA.
2 Seattle Cancer Care Alliance, G2-600, 825 Eastlake Ave E, Seattle, WA 98109.

2. Using Automated Breast Sonography as Part of a Multimodality Approach to Dense Breast Screening, Vincenzo Giuliano, MD, RDMS, RVT1, Concetta Giuliano, DO1, Journal of Diagnostic Medical SonographyJuly/August 2012 28: 159-165,

1Novasoutheastern University, Winter Springs, FL, USA
 
 
Written by: Dror Nir, PhD.

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