Researcher questions new study suggesting benefits of breast screeningBMJ 2018; 363 doi: https://doi.org/10.1136/bmj.k4790 (Published 13 November 2018) Cite this as: BMJ 2018;363:k4790
- Susan Mayor
- London, UK
A leading researcher in breast cancer screening has questioned the validity of a new observational study from Sweden which found greater benefit with breast cancer treatment in women taking part in screening compared with those not screened.1
“The study compared women who attended screening and those who were invited but did not attend screening. This is problematic in many ways because, when you compare those who comply with those who do not, you are comparing apples and pears,” said Mette Kalager, associate professor with the Clinical Effectiveness Research Group, University of Oslo, Norway, and previously head of the Norwegian Breast Cancer Screening Program. She added that changes in breast cancer treatment and care over time may also have influenced outcomes.
The effectiveness of breast cancer screening has traditionally been assessed by randomised trials of sending women screening invitations on breast cancer mortality. But the authors of the new study said …