Just one patient record remains under review by Imperial College Healthcare NHS Trust after the discovery that hundreds of urgent cancer referrals may never have been followed up.

Earlier this year, the trust wrote to GPs asking for help in tracing patients referred to it for treatment whose files had been duplicated or opened but not closed.

A spokesperson at the time said about 900 patients may have been affected.

A review group set up by the trust looked at 74 patients who had died and been affected by the problems, and one case remains under review.

To date, the group has found no correlation between the reason for death and the data reporting issues.

A spokeswoman for Imperial College Healthcare said 18 patients have been re-referred and none were found to have cancer after being seen.

“We have carried out a thorough clinical review of records of patients that were referred to us for suspected cancer where we had not recorded that the patients had been seen and, where appropriate, treated,” she said.

“To date we have found no evidence that these patients have come to clinical harm as a result of our poor record keeping.”

A joint letter from Westminster, Hammersmith and Fulham and Kensington and Chelsea councils this month said there were unhappy with a “lack of transparency” from the trust about the impact on patient care.

The trust told eHealth Insider that patient safety has been its “absolute priority” while these issues were addressed.

“We are extremely sorry that this situation was not identified and resolved earlier however, we would like to reassure our patients that this was an issue of poor record keeping not clinical care,” the spokeswoman said.

NHS North West London wrote a letter to all GP practices in May asking them to review all of their urgent cancer referrals over the past six months and consider a system to proactively track all future referrals.