The cases of up to 450 patients in the West Midlands are being investigated after a private hospital group found irregularities in a surgeon's procedures.
Mr Ian Paterson, who carried out the operations at the Spire Healthcare Hospitals in Solihull and Little Aston, was banned last year from carrying out breast surgery.
He was banned for using an unregulated procedure on his patients, which consisted of leaving some breast tissue behind during operations, in order to enhance cleavage.
This practice is said to increase the risk of cancer returning. It prompted an investigation that has led to the recall of more than 700 patients operated on at the NHS hospital.
- In 2004, Dr Paterson was investigated by Heart of England NHS Trust over the breast cleavage operation
- In 2007 he was told to stop performing the operations but continued
- In July 2011 he was banned by the General Medical Council from carrying out breast operations
- In August 2011 he was suspended by Spire Healthcare
The private hospital where they had their operations say they've found "irregularities which go against recognised treatment standards."
We put the claims to the Medical Defence Union, which represents Mr Paterson, and they told us he doesn't want to comment due to his duty of confidentiality to his patients.
A helpline has also been set-up for private patients who think they may be affected. Anyone who has concerns should call Spire Healthcare on 0800 044 3134.