This news release summarizes a pilot study conducted by Israeli researchers on non-traditional methods for screening for breast cancer. One method employed an electronic nose sensor that measured chemicals in human breath and another analyzed urine samples. The screening methods were 95% and 85% accurate, respectively, according to the release.
Key details were missing from the brief summary, including how many patients were screened and whether it was a randomized controlled study. The study was a pilot, designed to develop an accurate statistical model to use when testing urine and exhaled breath samples, according to the journal article, but the release does not tell us that.
Cancer screening is a topic of much debate among experts. Some screening methods have a large number of false positive results that may lead to unnecessary or risky biopsies or treatments. This release raises the expectation that cheaper and yet accurate methods could be available soon for breast cancer. But this method would require much larger experiments with many more patients before it could become widely available, if ever.
The news release never gives readers an estimate for the cost of a combination breath and urine screening test for breast cancer. The release does state that the technologies used for both urine and breath are “inexpensive” but doesn’t give us a concrete number to justify that claim.
The only benefits statement is that “researchers detected breast cancer with more than 95 percent average accuracy using an inexpensive commercial electronic nose (e-nose) that identifies unique breath patterns in women with breast cancer. In addition, their revamped statistical analyses of urine samples submitted both by healthy patients and those diagnosed with breast cancer yielded 85 percent average accuracy.”
Readers need the total number of patients screened and other details on how results of the study were measured.
It’s important to keep in mind that the study was about developing a better algorithm to funnel out the noise from these tests and focus on the signal that would indicate whether someone did or did not have cancer. Any benefit described should be related to the development of a better algorithm, versus developing a better physical test.
Screening methods typically include false positive results, which will require further testing that might include biopsy. The release did not mention this potential harm or any others from the proposed method of testing breath and urine.
This is not a 100% accurate test and there is no discussion on what happens when the test is wrong or why the test may not be accurate all of the time.
The release provides so little information on methods that readers can’t judge the quality of evidence. We aren’t given the total number of patients studied or how the experimental group was compared to a control group.
In the full journal article we’re informed that the study was a pilot, meaning it was a preliminary study to assess feasibility, harms and study design prior to launching a full-scale research study.
There was no disease mongering. The release provides some statistics on breast cancer prevalence, but then makes a tentative connection between early screening and breast cancer mortality which seems unwarranted given the preliminary status of the research.
The release does not give us information on funding or conflicts of interest. The full journal article states there are no conflicts.
The release discusses existing screening methods and offers some comparisons on safety and sensitivity, especially for dense breast tissue.
The release stated:
Mammography screenings, which are proven to significantly reduce breast cancer mortality, are not always able to detect small tumors in dense breast tissue. In fact, typical mammography sensitivity, which is 75 to 85 percent accurate, decreases to 30 to 50 percent in dense tissue.
Current diagnostic imaging detection for smaller tumors has significant drawbacks: dual-energy digital mammography, while effective, increases radiation exposure, and magnetic resonance imaging (MRI) is expensive. Biopsies and serum biomarker identification processes are invasive, equipment-intensive and require significant expertise.
It’s unfortunate that the release chose not to similarly include any drawbacks for the proposed electronic nose and breath screening methods.
The release quotes the lead author claiming: “We’ve now shown that inexpensive, commercial electronic noses are sufficient for classifying cancer patients at early stages.” This implies that such “noses” are already commercially available for breast cancer detection but we’re not told where they are available and how frequently they’re used.
The news release does not make clear that urine and breath tests have existed and been used for breast cancer, but the novel part of this study is the statistical analysis and modeling.
The release doesn’t employ sensational, unjustifiable language.