County Durham and Darlington NHS Foundation Trust will expand its investigation into breast cancer treatment after admitting that some women underwent unnecessary mastectomies. The review will now cover up to 4,500 additional cases dating back to 2015, with the process expected to take around five years.

The initial review examined 538 cases from 2023 to 2025 and found harm in 321, including one death; at least 20 women are known to have had unnecessary breast removal. Around 640 patients have requested reviews, while police and the National Crime Agency are investigating possible criminal offences. The trust has also faced scrutiny over private companies linked to former breast-services lead Amir Bhatti, who has been suspended from clinical practice.