While the increased detection rate no doubt helps women seek treatment earlier and avoid worse clinical outcomes associated with DCIS being undetected for longer periods of time, there also could be some unintentional consequences of heightened detection. Because DCIS does not necessarily precede invasive breast cancer, the increased detection “may result in overdiagnosis and overtreatment,” the authors cautioned in the study. However, this potential outcome exceeded the scope of the current study and would necessitate further analysis.

“It’s important to evaluate more-sensitive screening tools for their sensitivity, specificity, and additional costs incurred — both with the test, and downstream of the test — from increased biopsies, and decide if using the test is justified in your medical setting,” said Dr Jane Brock, MD, PhD, chief of breast pathology at Brigham and Women’s Hospital in Boston, Massachusetts. Dr Brock was not involved in the study and argued that “overdiagnosis” is itself an unclear way to measure outcomes.

“[Overdiagnosis] can mean non-cancer findings that are irrelevant, non-cancer findings that give a woman information she’s at increased risk of breast cancer, or even cancer findings that are not really clinically relevant in the course of a woman’s life,” Dr Brock explained. “I would rather…more accurate language like ‘it results in more biopsies being performed, which turn out to be benign findings.’”


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This study spanned 2001 to 2014 specifically to address a gap in the existing literature, which overall relied too heavily on data collected before digital mammography really took off in order to gauge its impact. The study cites a 2011 study in Radiology2 that posed similar questions but examined mammograms taken from 1996 to 2010. Just that 4-year difference in the data set means that the 2011 study results are skewed by film-screen mammography, making it difficult to assess how a digital change in diagnostic tools had really affected clinical outcomes. As a result, “much of what is known about DCIS upgrade rates is a result of [film-screen mammography] detection,” the authors wrote in the study, hoping that their results could change this.

The pace of diagnostic innovation is relentless. Even as answers become clearer regarding the role that digital mammography has played in the detection and upgrade rates of DCIS, a new tool looms on the horizon: synthetic mammography, approved in 2011 by the U.S. Food and Drug Administration. This approach recreates a 3D model of the breast from captured 2D images, and further studies will be needed to understand how it can affect clinical outcomes.

“It will be interesting to see where the DCIS detection rates and upgrade rates trend as [digital breast tomosynthesis] with synthetic mammography replaces [digital mammography] nationally,” concluded Dr Neal. 

References

  1. Neal CH, Joe AI, Patterson SK, Pujara AC, Helvie MA. Digital mammography has persistently increased high-grade and overall DCIS detection without altering upgrade rate. AJR Am J Roentgenol. 2021;216(4):912-918. doi:10.2214/AJR.20.23314
  2. Brennan ME, Turner RM, Ciatto S, et al. Ductal carcinoma in situ at core-needle biopsy: meta-analysis of underestimation and predictors of invasive breast cancer. Radiology. 2011;260(1):119-128. doi:10.1148/radiol.11102368