As women get older we all know they begin to fall apart. This can be due to excess bloating, migraines, crow's feet, cellulite, excess bikini line hair and shameful constipation that results in flat hair. Also flat hair. As if those afflictions weren't enough there is also the possibility of cervical cancer and breast cancer to contend with.
Then, in addition to the regular visits (those 3 years go faster and faster) from between the ages of 50 and 53 women receive a new invitation for breast screening. It's not taking your mammaries to the movies. It's taking your mammaries for a mammogram, which is fun to say but not particularly fun to do. Neither of these GP invitations are particularly welcome, they are uncomfortable, often hard to schedule and until you receive your all clear letter a period of worry.
Which is why it is both interesting and frustrating to see the Lancet publish the findings that an “Independent panel concludes that breast cancer screening reduces deaths, but overdiagnoses”. The panel was led by Professor Sir Michael Marmot, Director of the Institute of Health Equity at University College, London and was set up by the National Cancer Director for England, Professor Sir Mike Richards and Dr Harpal Kumar, Chief Executive Officer of Cancer Research UK. The panel acknowledges that breast cancer detected by screening generally allows for earlier treatment and an improved prognosis. However, the panel has raised concerns about overdiagnosis. Causing women to undergo surgery, radiotherapy and medication for a tumour which may have remained undetected for the rest of the woman's life without causing illness.
A problem with the task the panel set for themselves to analyse, acknowledged by the panel, is that the studies they analysed took place 20 years ago. Also there were only 3 randomised trials available, so reliable studies of overdiagnosis were rare. The panel concluded that women who attend screenings have a relative risk of breast cancer related death that is 20% less than those who are not invited to screenings.
Combining benefit and overdiagnosis from the figures found the panel estimate that for 10,000 women invited to regular screenings over 20 years from the age of 50, 681 cancers will be found. Of these 681 129 will represent overdiagnosis, while 43 deaths from breast cancer will be prevented.
What's the problem with overdiagnosis? Speaking on the Today Programme a woman who believes she was overdiagnosed, Miriam Pryke, discussed how she'd wanted to choose the option to 'wait and see' if the tumour found turned out to be cancerous. She was denied this option and treatment consisting of 2 operations was “done under duress.” Pryke claimed it was made very clear that she was not going to get any extra time to discuss her options with her consultant. You can watch another Pryke interview here about her over-treatment.
Pryke was accompanied by another woman who had undergone breast cancer treatment, Diane Dally who was informed after her mammogram that there was a tumour and was given a biopsy to confirm it was cancer. Dally opted immediately for a mastectomy: “I could not live with a breast that had cancer in.” Had Dally not attended her screening, which she only went to under her husband's urging, she said she would have “ended up in a psychiatric hospital” from the uncertainty.
The panel has perhaps created vindication for some, such as Pryke, awareness of overdiagnosis is as vital as regular screening. It also demonstrates how the patient's opinion must not necessarily be put down to fear or ignorance. I can see how these findings will create more uncertainty for some women. However what I hope is that it highlights for doctors the necessity of clear consent