* This is the second of a two part note trying to answer the question – breast cancer – to screen or not to screen?
* The research was prompted by an invitation to screening that I received. The accompanying booklet reported the key trade off as “for every 1 woman who has her life saved from breast cancer, about 3 women are diagnosed with a cancer that would never have become life threatening.”
* As no lives are going to be saved (we're all going to die), I wanted to know by how much might the 1 woman 'saved' have her life extended and by how much might the 3 women harmed have their life shortened. How many women would be screened and not saved or harmed?
* Part 2 explains the source of 3 key numbers in the screening debate:
- the 1,300 lives saved;
- the 1 saved for 3 overdiagnosed;
- the claimed life extension.
* My question was not fully answered, as I still don’t know by how much women treated unnecessarily have had their lives shortened. If screening has extended the life of 1 woman by X years and reduced the life expectancy of 3 women together by more than X years, it has net harm.
* Part 2 shares additional findings from my research into this topic:
- The average age of women dying from breast cancer;
- Doubt over the 1,300 lives saved estimate, because the outcome from real trial data was multiples different to this number;
- Mortality from all cancer and all-causes, not just deaths attributed to breast cancer;
- Lump size, doubling times and the lump size that screening can detect;
- Personal attacks on scientists questioning the value of mammography.
* Finally, I share my decision – to screen or not to screen – and how I reached it.
The rest of this article is available to site subscribers, who get access to all articles plus a weekly newsletter.
To continue reading, please login below or sign up for a subscription. Thank you.