This story clearly outlines how a study of mammography screening in Norway feeds into debate about the value of breast cancer screening. It includes the comments of experts who have a variety of perspectives on the latest data.
Women have been whipsawed by often confusing statements and claims about whether and when to get a mammogram. This story lays out how the latest study data points to benefits of screening… but that the benefits appear to be smaller than most people believe.
The story does not mention the cost of mammography (or of follow up tests and treatments) to the individual, or, collectively, to society. Based on the results of this study, 2,500 women would have to be screened every other year for a decade in order to prevent one death from breast cancer.
As the story points out, during that same time 1,000 of those women would have at least one false alarm and 500 would undergo an unnecessary biopsy, thus adding to the price tag.
The story reports both the 10 percent reduction in breast cancer deaths that the researchers attributed to screening, as well as the calculation that 2,500 women would have to be screened for a decade to prevent one breast cancer death.
The story points out that there are many false alarms among women who are screened with mammography and that most of the cancers that are found and treated would not have been lethal. It notes calculations from an editorial accompanying the study that for every breast cancer death prevented five or more women are treated for tumors that would never have become lethal.
The story accurately describes the study and highlights some of the advantages of the methods used in this study compared to earlier studies. We wish it had mentioned some of the limitations of the observational methods used. For instance, the researchers mentioned that a longer study may have found a larger benefit to screening. Nonetheless, we’ll give it the benefit of the doubt on this criterion.
The story does not exaggerate the threat of breast cancer and emphasizes that this study and others indicate that the effect of mammography screening is more modest than most women believe.
The story includes more than one independent source. However, the story does not tell readers the sources of funding, which were the Cancer Registry of Norway and the Research Council of Norway.
The story highlights experts talking about the decision about whether or not to get screening mammograms, and therefore addresses even the option of foregoing mammograms.
Although the availability of mammography is not at issue in this story, it could have pointed out that the researchers attributed most of the decrease in breast cancer deaths to multidisciplinary breast cancer management teams. While all the women screened by mammography in Norway had access to these expert teams, women in the U.S. who get mammography may not have access to this sort of treatment support.
In this case, the novelty of the approach is the study method. The story reports that Norway provided researchers with a unique opportunity, since mammography screening was phased in over a nine year period, thus allowing researchers to compare the outcomes of women who were screened to similar women who were not.
The story includes interviews and other information that does not appear to come from a news release.