BMJ Article on Breast Cancer Screening Effectiveness Incredibly Flawed and Misleading

A few days ago, Zujaja posted this article on 3QD, calling into question the value of mammograms. Here is a reply from the American College of Radiology:

According to the American College of Radiology and Society of Breast Imaging, the recent breast cancer screening article (Miller et al) published in the British Medical Journal (BMJ) (1) is an incredibly misleading analysis based on the deeply flawed and widely discredited Canadian National Breast Screening Study (CNBSS). The results of this BMJ study, and others resulting from the CNBSS trial, should not be used to create breast cancer screening policy as this would place a great many women at increased risk of dying unnecessarily from breast cancer.

Experts called on to review the CNBSS confirmed that the mammography quality was poor (2). The trial used second hand mammography machines, which were not state of the art at the time of the trial. The images were compromised by “scatter,” which makes the images cloudy and cancers harder to see since they did not employ grids for much of the trial. Grids remove the scatter and make it easier to see cancers. Also, technologists were not taught proper positioning. As such, many women were not properly positioned in the machines, resulting in missed cancers. And the CNBSS radiologists had no specific training in mammographic interpretation. The CNBSS own reference physicist stated that “…in my work as reference physicist to the NBSS, [I] identified many concerns regarding the quality of mammography carried out in some of the NBSS screening centers. That quality [in the NBSS] was far below state of the art, even for that time (early 1980s).”(3)

In this latest BMJ paper, only 32 percent of cancers were detected by mammography alone. This extremely low number is consistent with poor quality mammography. At least two-thirds of the cancers should be detected by mammography alone (4).

More here. [Thanks to Sughra Raza.]