Hospital chiefs have confirmed that 321 patients suffered some form of harm and that 32 cases involved excessive surgery, including 20 unnecessary mastectomies, in a breast cancer care controversy that has forced County Durham and Darlington NHS Foundation Trust to consider a sweeping review of up to 4,500 cases dating back to 2015.

The trust's 'lookback' review, launched in April 2025 after serious concerns were raised about breast cancer care, initially covered cases from January 2023 to February 2025.

At an extraordinary public board meeting in Durham, officials confirmed that 538 cases had been examined up to 2 September 2026, with one patient having died and 78 suffering severe or moderate harm, while 20 cases involving delayed diagnosis had also been identified.

Chief nurse Gill Hunt told the board that worries about the trust's breast services were first raised in 2015, after a service reconfiguration led to the loss of breast surgical trainee posts.

She said patients and bodies including the Northern Cancer Alliance, the Care Quality Commission and NHS England had repeatedly raised concerns in the years since, citing excessive surgery, delays and care that fell short of best practice.

The board has now agreed that once the current review period is completed, the exercise will move to 2022 cases and then work backwards, year by year, towards 2015.

If it runs its full course, the review is expected to take in around 4,500 additional cases and could take five years to complete, meaning some women treated in 2015 may not have their notes examined until 2031.

Chief executive Steve Russell called it a 'difficult decision'. He said: 'We remain deeply sorry for the harm and distress caused, and for the times when, as a trust, we should have listened more carefully, asked more questions and acted sooner.'

Russell said the board had weighed clinical evidence, independent advice and differing views from patients and families. Some women had said they did not want their care revisited, fearing it would be traumatic, while others argued every potentially affected patient should be checked regardless of how long ago they were treated.

The trust said patients identified as affected would be contacted directly, though they will be able to opt out. External specialists are carrying out the reviews, with nine reviewers currently assessing around 80 cases a month, at a first-year cost of about £523,000.

The meeting drew women who said they were harmed by treatment at the trust, many belonging to the Pink Justice Network, a support group of around 150 former patients. Co-organiser Nadeen Lister said she was 'upset' by the scale of the review and questioned how many more women could be affected.

She said the trust still needed to establish the full numbers, even if some patients preferred not to know.

Others said the review should reach further back than 2015, with medical negligence solicitor Chloe Gibson, who represents some of the women, warning the process would be 'very long' and saying delays in getting answers into the 2030s risked 'further anxiety and trauma'.

Emma Brewster, who attended the meeting, told ITV Tyne Tees the review 'should go further back' and that 'every woman has a right to know whether they've been failed or not'. Hayley Collinson of Hudgell Solicitors said cost and capacity concerns should not limit the review's scope, saying the trust 'needs to put the resources behind this'.