Rate of misdiagnosis significant, says author

THE cancer misdiagnosis rate at a Portlaoise hospital was a “very significant rate of misdiagnosis” according to the clinician who reviewed more than 3,000 mammograms originally read at the hospital.

Yesterday, consultant radiologist Dr Ann O’Doherty, who carried out the review, said she wished to clarify that a misdiagnosis rate of nine patients out of 3,000 was a “very high level of misdiagnosis” and not within the normal range.

Dr O’Doherty aired her clarification on RTÉ’s Morning Ireland to correct any impression given by health officials or in the media that the Portlaoise misdiagnosis rate was comparable with misdiagnosis rates in other care centres.

In her clinical review of mammography services at the Midlands Regional Hospital in Portlaoise, Dr O’Doherty said: “The false negative rate in this review on aggregate falls within the false negative rates published within similar reviews.”

She said this had been interpreted in some quarters as a misdiagnosis rate within the normal range when compared with other breast care services, when in fact her comparison was with other reviews of misdiagnosis. Dr O’Doherty cited a review of 6,000 mammograms in the North three years ago which had uncovered six misdiagnoses.

“Approximately 1% of women who go to good centres have a delayed diagnosis, in this case it was 6%. This is a high level of misdiagnosis,” she said.

Dr O’Doherty’s report was also critical of the equipment used at the hospital, saying “there is no doubt it was a factor”. However, she pointed out that the mammograms included in her review — which uncovered the nine misdiagnoses — were the same mammograms read by staff in Portlaoise.

Dr O’Doherty, who works at St Vincent’s Hospital Dublin and is clinical director of the Merrion Unit of BreastCheck, urged women to attend centres of excellence when seeking breast cancer treatment.

“If women go to a centre of excellence, there is a 20% improvement in survival rates... when you go for triple assessment you have a mammogram, ultrasound and a whole clinical evaluation and you are not relying on one test,” she said.

Dr O’Doherty said in her 10 years working to improve Irish breast cancer services, she feels “great hope” for the first time because she believes Health Minister Mary Harney is sincerely committed to improving cancer care.