“Data collection” issues at Imperial College Healthcare NHS Trust mean it may not have received hundreds of urgent cancer referrals over the past year.

Londonwide Local Medical Committees has issued an alert to GPs saying that “potentially a significant number of patients” referred under the two-week cancer referral rule up to one year ago may not have received an urgent cancer referral.

The alert says practices may receive a request from the trust relating to cancer appointments and urges them “to offer all assistance promptly."

An Imperial College Healthcare spokeswoman said the problem was related to “data collection” and about 900 patients may have been affected.

“We are in the process of clinically validating all records that indicate that a patient may have been waiting longer than two weeks for a referral for suspected cancer,” she said.

“The validation process involves contacting GP practices to review clinical records to ascertain whether the patient has received treatment or still requires treatment, their correct waiting time, and to agree the most appropriate course of action.”

To date, the trust has found no suggestion that any delay in treatment has caused a patient to come to serious harm.

“The safety of our patients is an absolute priority and we are working with the Department of Health Intensive Support Team and our commissioners to take all necessary steps to clean up our data to ensure it is accurate, improve our systems and processes, and make sure all patients referred to us have been treated in a timely manner according to their clinical need,” she said.

The Londonwide LMCs alert says it has asked the trust to contact patients in the first instance in order to minimise the impact on practices.

“If timely patient contact proves difficult, then Imperial College may request your urgent assistance in contacting your patients or their carers/representatives, in which case Londonwide LMCs anticipates you will wish to respond,” it says.