County Durham and Darlington NHS Foundation Trust (CDDFT) has expanded its investigation into breast cancer treatment errors, with plans to review an additional 4,500 cases dating back to 2015. This increase follows an initial assessment of 538 cases in which 321 patients were found to have suffered harm, including at least 20 women who underwent unnecessary mastectomies. One patient among those reviewed has died.

The decision to broaden the inquiry was announced during a trust board meeting after a helpline established by CDDFT received over 600 calls from women seeking reassessment of their care. The review, which already spanned nearly a year, has involved nine reviewers examining approximately 80 cases monthly at a cost of about £523,000. The trust aims to extend the review one year at a time back to 2015, with the entire process expected to take up to five years to complete.

Initial concerns about the breast cancer service emerged in 2015 following a departmental reorganisation and the loss of breast surgical trainee posts. Previously, the trust estimated it might need to review as many as 10,000 cases but has since committed to a lower figure of 4,500 additional cases.

The trust's board expressed a “sincere apology” to the affected women and their families and has pledged to learn from the findings. The National Crime Agency is collaborating with Durham Constabulary to investigate whether any criminal offenses were committed in connection with the treatment errors.

Amir Bhatti, a consultant who served as CDDFT’s clinical lead for breast services from 2013 until 2024, has been suspended from clinical practice during the ongoing internal review. He remains employed by the trust and is receiving full pay while investigations continue.