Even the best cancer systems will never be 100% accurate

Sat, Oct 13, 2012, 01:00

ANALYSIS:A new standardised system has taken some of the shortcomings and inconsistencies out of breast cancer diagnosis

“[MEDICINE] IS an imperfect science, an enterprise of constantly changing knowledge, uncertain information, fallible individuals, and at the same time lives on the line.”

An overall explanation for the figures for legal actions taken against Irish hospitals for alleged cancer misdiagnosis over the past eight years is encapsulated in this quote from Dr Atul Gawande, a Boston surgeon and medical safety advocate.

But in the specific case of missed breast cancer diagnosis it does not explain why there is a mismatch between the numbers of cases of breast cancer in the Republic and the percentage of legal actions this particular cancer attracts for alleged misdiagnosis. Breast cancer makes up about 10 per cent of cancer diagnoses here annually while in this series of 100 legal actions, breast cancer misdiagnosis represented 28 per cent of cases.

Given the historical nature of legal figures, a major factor in the discrepancy is undoubtedly the parlous state of breast cancer services in the State prior to their reorganisation under our first director of cancer control, Prof Tom Keane. It was Keane who set up a network of eight cancer centres and, significantly, he chose breast cancer as the first type of tumour around which to reorder what was a haphazard system of care. A detailed reading of the case taken this week by Olive Fahey illustrates many of the shortcomings and inconsistencies he faced.

By organising a standardised system of multidisciplinary team working (MDT) and triple assessment for women presenting with symptoms of breast cancer, Keane has ensured absolute consistency in the diagnostic process. The triple assessment of a breast lump in a dedicated clinic means that a woman will undergo radiology (usually a mammogram), examination by a specialist breast surgeon and a biopsy of the lump, which will be examined by a pathologist specially trained in breast pathology.

A key factor in good cancer care is to have all health professionals involved in a person’s care located in one place, enabling MDT to take place.

The reason this makes an important difference is that some cases can be difficult to call. For example, the mammogram and the biopsy may be negative, but the surgeon and/or the radiologist will still be concerned about the nature or consistency of the lump.

In a 2007 comment to The Irish Times, Keane emphasised the importance of the public understanding that even the best-quality cancer system will never be 100 per cent accurate. He said: “False positives and false negatives are a feature of all diagnostic testing. No technology is 100 per cent accurate – it is a subjective science.”

Even in the best cancer centres in the world, using the most up-to-date equipment and a multidisciplinary approach, medical error will occur. Because of this the State Claims Agency will continue to settle cases of cancer misdiagnosis. The best we can hope for is that the rate of misdiagnosis will continue to fall.

Key Figures

In total 100 claims for alleged cancer misdiagnosis were received by the State Claims Agency between 2004 and 2011. The five main types of cancer misdiagnosis claims lodged were:

Breast 28

Lung 13

Gynaecological 9

Prostate 5

Lymphoma 4

Cancer misdiagnosis claims settled by the State Claims Agency since 2004:

Six* breast cancer misdiagnosis cases: €190,000 – average payout to patients; €60,000 – average legal costs paid by the State Claims Agency, including plaintiff costs

Three lung cancer misdiagnosis cases were settled: €43,000 – average payout to patients; €41,000 – average legal costs paid by the State Claims Agency, including plaintiff costs

Three gynaecological cancer misdiagnosis cases settled: €53,000 – average payout to patients; €65,000 – average legal costs paid by the State Claims Agency, including plaintiff costs

Seven other cancer misdiagnosis cases settled: €112,000 – average payout to patients; €85,000 – average legal costs paid by the State Claims Agency, including plaintiff costs

*excludes the case of Olive Fahey settled this week