SINGAPORE: At least 200 patients were wrongly classified as having a more aggressive form of breast cancer than their actual condition due to a lab error at Khoo Teck Puat Hospital (KTPH), Senior Minister of State for Health Koh Poh Koon said in Parliament on Monday (Jan 4).
The authorities revealed last month that 180 patients were affected by the wrong diagnosis and half of them may have received unnecessary treatment.
The patients were wrongly classified as being positive for HER2 - a gene that controls how a healthy cell grows - instead of HER2 negative. This affects how a patient is treated, most commonly with a drug called Herceptin.
Common side effects due to HER2-directed treatment include diarrhoea, chills and fatigue. About 3 to 4 per cent of patients may also experience heart problems.
READ: About 90 breast cancer patients may have received unnecessary treatment after inaccurate classification of 180 cases: KTPH
Responding to parliamentary questions about the incident, Dr Koh said 200 patients have been reclassified from HER2 positive to HER2 negative as of Dec 23.
Of these, eight patients were treated at private hospitals and 192 patients at government-run hospitals. Eight patients are pending retests.
"Joint care teams have been formed, comprising KTPH surgeons, histopathologists and the treating oncologists, to review the individual care plans for these affected patients, based on the change in HER2 status," said Dr Koh.
The hospital is also reviewing the bills of the affected patients, Dr Koh said, adding that the costs incurred by patients due to unnecessary treatment will be fully refunded.
The amount each patient will be refunded will depend on several factors, including the length of their treatment and the hospital they went to, he added.
"KTPH is also ready to provide any clinical and financial support to the affected patients including on-going or follow-up treatment, if any, which may be needed as a result of over-treatment," Dr Koh told the House.
The National Healthcare Group has convened an independent review committee, comprising external experts from various disciplines in the healthcare industry, to conduct a "thorough evaluation of the incident" and to recommend measures to improve the process. he said.
"This ensures that any system gaps are identified and addressed swiftly to prevent recurrence of similar incidents," he added.
KTPH first started testing patients for HER2 in 2012.
Responding to questions about the efficacy of the test and why it took eight years for the problem to surface, Dr Koh said that testing for HER2 is a complex process and it took years for a significantly higher-than-normal positivity rate to appear before it was clear there was an issue with the results.
Dr Koh also clarified that although KTPH is reassessing results from 2012, it does not mean that all the results since 2012 were wrong.
“It may well be that the errors could have occured in the last three months or six months (but) KTPH is being prudent and careful by going back … all the way to when the test first started,” he said.
When Non-Constituency Member of Parliament Hazel Poa asked if it is possible these patients receive lifetime free healthcare as compensation, Dr Koh rejected the suggestion as most of the side effects from HER2 treatment are temporary.
As for whether the patients will be offered mental health support financially, Dr Koh said the decision lies with the medical team helping the patient.
“A panic attack or anxiety episode can occur with or without cancer, it can occur with or without treatment,” he said.