Last month, the results from 25 years follow-up of a Canadian trial into mammographic screening for breast cancer were published. The conclusion: breast cancer screening could be doing more harm than good.
The study found no benefit, in terms of reduced mortality, in women who were screened. More concerning, though, was the conclusion that one in five women who were treated for breast cancer in the screened group were unnecessarily treated — they potentially had lumps or entire breasts removed, were subjected to radiation therapy, hormone therapy, or chemotherapy, when their cancers would not have posed them any threat in their lifetime. In other words, they were over-diagnosed.
The line between benefit and harm when it comes to breast screening seems to be getting ever finer. Other studies have also pointed to significant rates of over-diagnosis in breast screening, yet advocates — and many women who have had lumps detected by mammography — maintain that screening is beneficial.
I recently wrote a piece for ABC Health & Wellbeing that tries to pick through the data. For many, the bottom line is that whatever the evidence, women should be given all the information available about benefits as well as potential risks, especially given that they are being invited to participate voluntarily. Check it out here.