Which is Better – Film or Digital Mammography?

Breast cancer and high grade DCIS detected with digital mammography

(RxWiki News) Film – X-ray film – has been used for taking mammograms for over 40 years. The main problem with film is that it doesn’t pick up everything. And as with everything else in the world, along comes a digital form of mammography.

Digital mammography is better than screen film mammography at picking up serious breast cancers -- without over-diagnosing the disease.

"Find out what type of mammography you will receive."

A research team from the Netherlands concluded this after reviewing and comparing the outcomes of women receiving both digital mammography (DM) and screening film mammograms (SFM) between the years of 2003 and 2007.

Adriana M.J. Bluekens, MD, from the National Expert and Training Centre for Breast Cancer Screening in Nijmegen and St. Elisabeth Hospital in Tilburg, both in the Netherlands, led the study.

The biggest concern is the detection of ductal carcinoma in situ (DCIS) – which can develop into invasive breast cancer, but doesn’t always do so.

Some DCIS can develop over decades without being a problem. On the other hand, there is more aggressive DCIS – life-threatening disease – that does need to be identified and treated as quickly as possible.

Breast cancer specialist, Patrick Maguire, MD, who was not involved in this study, told dailyRx News, “The problem of ‘over-diagnosis’ related to cancer screening tests is one that's generally under appreciated."

A concern with the use of digital mammography (DM) for breast cancer screening relative to the older screen film mammography (SFM) has been the potential for relatively increased detection of abnormalities that are not life threatening, including low grade ductal carcinoma in situ (DCIS), pre-invasive cancer,” said Dr. Maguire, who is a radiation oncologist in North Carolina and author of When Cancer Hits Home: An Empowered Patient is the Best Weapon Against Cancer.

For the study, nearly two million mammograms were reviewed. Compared to SFM, researchers found that digital mammography:

  • Detected more cancers – 6.8 per thousand vs. 5.6 for SFM
  • Detected more serious high-grade DCIS – 58.5 percent vs. 50.5 percent
  • Had a higher recall rate – 4.4 percent compared to 2.6 percent.

“This large multi-center Dutch study provides solid early evidence that DM increases detection of high-grade (more aggressive) DCIS and invasive breast cancer, but does not disproportionately detect low grade DCIS versus SFM,” Dr. Maguire said.

“Long-term follow-up will be critical to determine the ultimate value of DM: whether it decreases the risk of death from breast cancer compared to SFM.”

Dr. Bluekens said, "The follow-up period of the different digital screening programs is not sufficiently long enough to analyze mortality effect separately from that of SFM."

Researchers note these numbers are probably not applicable to the U.S. That’s because screening programs here focus on high detection rates, while Dutch screening focuses on balancing detection, recall rates and false-positives.

This study was published online October 2 in the journal Radiology.

No conflicts of interest pertaining to this research were reported.

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Review Date: 
October 2, 2012