On 2016 Apr 20, Daniel Corcos commented:

There is a serious bias in this study, as the mutation status for the cases was determined after diagnosis, whereas the controls were at-risk women. The large majority of the cancers were not diagnosed by screening mammography, indicating that screening was not performed efficiently in this group. On the contrary, being at-risk implicates implementation of screening, and, as a consequence, more mammograms in this group.

On 2016 Apr 20, Daniel Corcos commented:

There is a serious bias in this study, as the mutation status for the cases was determined after diagnosis, whereas the controls were at-risk women. The large majority of the cancers were not diagnosed by screening mammography, indicating that screening was not performed efficiently in this group. On the contrary, being at-risk implicates implementation of screening, and, as a consequence, more mammograms in this group.