A woman died after her stomach cancer went undiagnosed for months, despite biopsies from three separate procedures initially finding no malignancy, prompting calls for an independent review of histology testing in Invercargill.

Patient Voice Aotearoa says it wants the Government to examine histology testing undertaken for Invercargill patients by Awanui Labs from 2021 to 2023, following a recent report by the Health and Disability Commissioner (HDC) into the case of a retired nurse whose gastric adenocarcinoma was not identified in two biopsies taken in 2021.

According to the HDC report, an oncologist concluded that “a two-month delay in diagnosis caused clinically meaningful cancer growth … and had a negative impact on her outcome”.

Biopsies viewed by Awanui Labs showed cancer cells twice, but it was not picked up.

The Invercargill woman’s stomach cancer went undiagnosed for about eight months, with biopsies taken during three separate gastroscopies in 2021 initially reported as showing no malignancy before a fourth procedure on Christmas Eve confirmed gastric adenocarcinoma.

A later hindsight review found the cancer had in fact been present in at least two of the earlier biopsies, and she died in May 2022 after being referred for urgent treatment.

Patient Voice Aotearoa chair Malcolm Mulholland said the case raised wider concerns about pathology services in the lower South Island.

“This smacks of a corporate cover-up,” Mulholland said in a statement.

“A case of a public service being privatised, so much so that the cuts that have been made to New Zealand’s pathology service to make a quick buck are now impacting harmfully on the health of patients.

“I hope there has only been one misdiagnosis, as no one wants to see another Cartwright Inquiry when system failures result in premature death.”

Mulholland said Patient Voice Aotearoa had been informed that the pathologist responsible for Invercargill retired in 2021 and that the caseload was transferred to Dunedin pathologists already under pressure from high workloads.

The group questioned whether the centralisation of services may have contributed to missed diagnoses and said “only an independent inquiry will provide patients with surety that the diagnosis they received was correct”.

However, both Health New Zealand Te Whatu Ora and Awanui said there was no evidence of a wider systemic issue.

Patient Voice Aotearoa chair Malcolm Mulholland said the case raised wider concerns about pathology services in the lower South Island. Photo / RNZ, Jimmy Ellingham

Health New Zealand Te Waipounamu chief medical officer Dr David Gow said the agency acknowledged the concerns raised and the HDC report, but did not currently support an independent review.

“At this stage, there is no evidence to suggest a wider systemic issue requiring an independent review. However, we will continue to monitor performance and would consider further action if new information arises,” Gow said.

He said Health NZ expected all contracted providers to deliver safe, high-quality services and to act on findings from independent reviews, adding Awanui had accepted the HDC recommendations and implemented changes.

Awanui chief medical officer Dr Richard Steele said the laboratory provider accepted the HDC findings “in full”.

“Awanui Labs accepts the recent findings of the Health and Disability Commissioner in full and, most importantly, acknowledges the harm caused to the patient and her whānau,” Steele said.

“We are deeply sorry for the distress and impact this has had and extend our sincere apology.”

Steele rejected claims that histology services in Invercargill had ceased, saying specimen processing (preparing the tissue for microscopic examination) had continued locally and only reporting (diagnosis of the slides by a pathologist) had been handled in Dunedin since 2020.

“Histology services have continued to operate in Invercargill and samples are still processed locally. Since 2020, reporting has been undertaken in Dunedin as part of Awanui’s national laboratory network,” he said.

He said the model was standard practice and allowed access to specialist expertise, peer support and quality oversight.

Awanui also said it had undertaken an internal review following the HDC findings and introduced new safeguards, including requiring pathologists to review endoscopy information alongside biopsy samples and increasing training and peer review.

“That review did not identify evidence of a broader systemic issue during the period concerned,” Steele said.

Patient Voice Aotearoa said questions remained over staffing levels for pathology services in the lower South Island and whether the service model was fully disclosed during the HDC investigation.

Ben Tomsett is a multimedia journalist based in Dunedin. He joined the Herald in 2023.