Screening MRI for breast cancer: news release is strong on costs and novelty

Does the news release adequately explain/quantify the harms of the intervention?

Not Satisfactory

The news release does not state any potential harms of MRI screening. False positives from MRIs aren’t uncommon and can lead to anxiety and additional invasive testing. That’s harmful for patients.

We’d like to see news releases and stories start to acknowledge potential harms, particularly since the country is moving toward more universal breast cancer screening with MRI.

Over the past few years, studies have been coming out noting concerns about the gadolinium (a heavy metal) contrast material that is used during breast MRI. The contrast is necessary to demonstrate areas of increased tissue vascularity (the state of blood vessel development and functioning). Recent reports note that gadolinium may deposit in the brain. We do not know the long-term significance of this. The FDA is studying the effects — if any– on “repeated use of gadolinium-based contrast agents (GBCAs) for magnetic resonance imaging (MRI).”

Does the news release seem to grasp the quality of the evidence?

Not Satisfactory

The release provides a nice summary of the study protocol, noting that:

“Between 2005 and 2013, Dr. Kuhl and colleagues studied breast MRI’s impact on 2,120 women, ages 40 to 70, with less than a 15 percent lifetime risk of breast cancer. The women had normal screening mammograms and, in the case of those with dense breast tissue, normal screening ultrasound. Breast MRI detected 60 additional breast cancers, including 40 invasive cancers, for an overall supplemental cancer detection rate of 15.5 per 1,000 women. Of the 60 cancers detected in the study group over the observation period (7,007 screening rounds), 59 were found only using MRI, one was found also by mammography, and none by mammography or ultrasound alone.”

Unfortunately, the release isn’t clear about the limitations of the study. The study doesn’t show that MRI offers benefits that women really care about such as longer life and better quality of life. The only way to prove such benefits would be in a large-scale controlled trial that follows groups of women (those who do and don’t receive breast MRIs) for many years. The release also fails to mention the risk of over-diagnosis and over-treatment. Finding more cancer at an early stage is not always a good thing, because some cancers don’t progress to a point where they would cause harm. While the release suggests that many of the cancers that were found were aggressive in nature, it doesn’t say how many, nor does it caution that some of these cancers might never have caused a problem. It also doesn’t warn that some particularly aggressive cancers might not respond to treatment despite early detection.

The published research noted that the screening studies were read by specialized breast radiologists and that the results “may not be transferrable to a community level until more radiologists gain practical experience in reading breast MR screening studies.” That would have been a useful addition to the release as well.

Does the news release commit disease-mongering?

Not Satisfactory

Breast cancer’s prevalence in cancer-related deaths in women was highlighted but not overstated.

But we aren’t told whether the 20 cases of non-invasive cancer identified were ductal carcinoma in situ (DCIS). There’s wide debate on whether the presence of these types of abnormal cells should even be referred to as cancer. The lack of clarity on the types of cancer identified and the difference between them earns a Not Satisfactory rating.

Does the news release identify funding sources & disclose conflicts of interest?

Not Satisfactory

The release doesn’t name the sponsors.