Health NZ Te Whatu Ora breached the code for patients' rights after failing to detect a man's renal cancer three times, the health watchdog has found.
The man - known in the report by the Health and Disability Commissioner as Mr A - had been under the care of vascular surgery services at Christchurch Hospital for annual surveillance of kidneys and spleen artery aneurysms since 2010.
He was diagnosed with renal cancer in September 2021 which in November of that year saw his left kidney removed.
Deputy Health and Disability Commissioner Deborah James said Te Whatu Ora Waitaha Canterbury (previously Canterbury DHB) missed three opportunities to spot the disease.
The first missed opportunity followed a CT angiogram in March 2019, when the man was referred to nephrology to investigate a renal cyst which was not actioned.
The second was in December 2019 when there was a failure, at the time of an ultrasound, to recognise the earlier missed follow up.
A third opportunity was when a recommendation to further investigate a renal lesion was not actioned in January 2021.
James found the CDHB breached the Code of Health and Disability Services Consumers' Rights for failing to provide services of an appropriate standard.
James said the vascular surgery service also failed to apologise to the man or inform him of how the incident would be managed, or about the complaint process.
"I am critical that CDHB failed to provide Mr A with open disclosure about the January 2021 error and did not engage in a timely discussion with him about his plan for care once the error was identified."
Since the events, Health NZ Waitaha Canterbury has formally apologised to the man and put in place changes.
These included an electronic referral system and updating vascular surveillance protocols to include, as a threshold for referral, "any other anomaly / unexpected change to appearance".
James acknowledged the changes the health agency has made and made recommendations.
These included Health NZ providing the man with confirmation of his recorded details and copies of letters he said he never received.
She also recommended a meeting be organised between Mr A and a doctor involved with his care.