More than 600 people may have suffered as a result of delays in outpatient appointments at the hospitals run by the Morcambe Bay Hospital Trust, which includes the Westmorland General in Kendal.
The trust has contacted 19,000 patients who had their outpatient appointments delayed to explain that their care may have been affected.
The University Hospitals of Morecambe Bay NHS Foundation Trust reviewed all outpatient appointments and found that 663 people may have been adversely affected as a result.
Sir David Henshaw, the interim Chair of the Trust, said: “It is unacceptable that these delays occurred. Local people are right to feel that they have been let down by this Trust in the past.
"The problems are being addressed. There is still a lot to do but I want to be clear: providing safe, high quality patient care will always be our priority. We will not preside over unsafe services."