Hospital chiefs in County Durham have agreed to review up to a further 4,500 breast cancer cases after failings including delayed diagnoses and unnecessary surgeries were found.

Hundreds of patients suffered harm under County Durham and Darlington NHS Foundation Trust, according to a review of cases dating back to 2023.

The BBC previously investigated the failings and has spoken to multiple women affected, including one who said she felt “mutilated” and the trust’s mistakes were “absolutely unforgivable”.

Ahead of agreeing to expand the review to cases dating back to 2015, members of the trust’s board offered “sincere” apologies for the failings and harm caused.

At an extraordinary meeting of the board held in Durham, board chair Alison Marshall said: “I would like to offer a sincere apology to all the women and their families who have been affected by the failings in our breast services.

“I can’t imagine the impact that has had.”

She said they could “not turn back the clock” but would be “open, honest and transparent” about the failings.

Chief nurse Gill Hunt told the board concerns were first raised in 2015 after a “service reconfiguration” and loss of breast surgical trainee posts.

Over the following years patients and bodies such as the Northern Cancer Alliance, Care Quality Commission and NHS England raised multiple issues, she said.

The key “themes” included treatment “not aligned to best practice”, excessive surgery and delayed diagnosis, she said.

The trust’s breast surgery lookback review began in April 2025 by examining cases between January 2023 and February 2025.

Hunt said 538 cases had been reviewed so far with 321 having experienced some form of harm, including one death.

About 640 patients had also contacted a special helpline asking for their cases to be reviewed, the board heard.

The review cost about £523,000 in its first year and involved nine reviewers looking at about 80 cases a month, the report said.

The board agreed to extend the review by one year at a time back to 2015, which would encompass up to 4,500 further cases and take an estimated five years to complete.

Hunt said the expanded review would “provide a proportionate and evidence-led clinical approach” in response to “emerging findings”, while decisions would be “supported by clear clinical rationale and formal governance review”.

Other “important learning” to come out of the review so far was about how bosses should respond to concerns raised by patients or other agencies, Hunt said.

“We are committed to doing the right thing,” she said.

Chief executive Steve Russell said the trust was “incredibly conscious women and their families” had experienced “distress, uncertainty and harm”.

He said no apology could undo that but the trust would “support women who have been impacted” in any way possible.

For example, some women who had undergone unnecessary mastectomies could be offered breast reconstruction surgery as they previously should have been, Russell said.

He also said the trust was currently exceeding national standards for breast cancer treatment, including for the number of women having breast conservation surgeries and being offered immediate reconstruction.

“None of that changes what has happened to women in the past but hopefully gives confidence the changes made in the service have had an impact on the outcomes,” Russell said.

He said patients today could be “confident” they would be “treated appropriately” and get “good clinical outcomes”.

The helpline, which is available by phone or email, would remain open with any concerned patients encouraged to contact it “irrespective” of when they were treated, he said.

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