Pleural mesothelioma surveillance: validity of cases from a tumour registry

Our plain-English summary of Pleural mesothelioma surveillance: validity of cases from a tumour registry, by F. Labrèche, B.W. Case, G. Ostiguy, et al (Canadian Respiratory Journal, 2012).

The study

• Authors: F. Labrèche, B.W. Case, G. Ostiguy, J. Chalaoui, M. Camus, J. Siemiatycki
• Journal: Canadian Respiratory Journal
• Published: 2012;19(2):103-7
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Pleural mesothelioma is a rare tumour associated with exposure to asbestos fibres. Fewer than than one-quarter of cases registered in the Quebec Tumour Registry (QTR) have been compensated as work-related. While establishing a surveillance system, this led to questioning as to whether there has been over-registration of cases that are not authentic pleural mesotheliomas in the QTR.

Objective: To assess whether registered cases of pleural mesothelioma could be confirmed.

Methods: A medical chart review was designed to assess the proportion of mesothelioma cases newly registered in the QTR in 2001⁄2002 that could be confirmed. For each registered case, clinical, medical imaging and pathology information were sought and, occasionally, additional immunohistochemistry staining was obtained. Three specialists - a chest physician, a radiologist and a pathologist - reviewed the available information and material, coding each mesothelioma case as to degree of certainty of the mesothelioma diagnosis.

Results: The QTR reported 190 incident cases of mesothelioma (81% males) for the period. The specialists classified 81% of charts as 'certain⁄probable' or 'possible' mesotheliomas, 8% as 'unlikely to be a mesothelioma' and 11% as 'not a mesothelioma'. After excluding chart summaries of unsatisfactory quality, 87% to 88% of the charts were classified as 'certain⁄probable' or 'possible' mesotheliomas, and 9% to 11% were still considered 'not a mesothelioma'.

Conclusion: Tumour registry data are a valid source of information for mesothelioma surveillance. While there is some over-registration of mesothelioma cases in the QTR, a significant majority of registered cases appeared to be authentic. Over-registration cannot explain the greater proportion of cases that were not compensated.

In plain English

This study checked whether pleural mesothelioma cases recorded in the Quebec Tumour Registry were genuine. The registry listed 190 cases newly diagnosed in 2001 and 2002 in 57 hospitals, and 187 medical charts were accessible. A respirologist, a radiologist and a pathologist reviewed chart summaries, imaging and available pathology material, then agreed on a consensus diagnosis. Of the 176 cases they could classify, 61.9% were judged 'definite/probable' mesothelioma, 19.3% 'possible', 7.9% 'unlikely' and 10.8% 'not a mesothelioma'. Another 11 cases could not be classified. Among cases with satisfactory chart summaries, 77% were 'definite/probable'. Among cases with satisfactory pathology data, the figure was 73%. In both groups about 10% remained 'not a mesothelioma'. Asbestos exposure recorded in the charts was not associated with whether a diagnosis was confirmed. The authors concluded that most registered cases appeared authentic despite some over-registration, and that the registry is a valid source for mesothelioma surveillance. They also concluded that over-registration cannot explain why a greater proportion of cases were not compensated. The authors noted that reviewing only chart summaries could have increased uncertainty, and that under-registration could not be estimated.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Validation study based on a medical chart review by three specialists (respirologist, radiologist, pathologist), with a final consensus diagnosis
• Who was studied: All 190 pleural mesothelioma cases newly diagnosed in Quebec between January 1, 2001 and December 31, 2002 and registered in the Quebec Tumour Registry, from 57 hospitals. 187 medical charts were accessible (152 men, 35 women).
• Exposure: Not an exposure study; the study examined the accuracy of registered diagnoses. Asbestos exposure noted in the charts was recorded but deliberately not used in confirming diagnoses. No fiber types are named.
• Main results:
  • Of the 176 classifiable cases (187 charts minus 11 'impossible to classify'), 109 (61.9%) were classified 'definite/probable' and 34 (19.3%) 'possible' mesothelioma.
  • Overall reclassification: 143 (81%) definite/probable or possible, 14 (8%) improbable and 19 (11%) not mesothelioma.
  • The 'definite/probable' proportion rose to 77% (51 of 66) among patients with a satisfactory chart summary, and to 73% (104 of 142) among those with satisfactory pathological data.
  • The proportion classified as 'not a mesothelioma' stayed at about 10% whether or not the specialists found the material satisfactory.
  • Of the 109 'definite/probable' cases, 64.2% were epithelioid, 18.3% biphasic and 13.8% sarcomatous mesothelioma.
  • Among charts with at least a pathology report, the respirologist/radiologist team and the pathologist gave exactly the same category for 64.0% (98 of 153). They agreed within one category for 88.2% (135 of 153).
  • Asbestos exposure indexes (pleural plaques and asbestos exposure recorded in the charts) were not associated with diagnostic confirmation. For example, asbestos exposure as noted by the specialists was found in 52 of 143 confirmed (36.4%) and 14 of 44 unconfirmed (31.8%) cases, P=0.72.
• The authors' conclusion: The authors concluded that tumour registry data are a valid source for mesothelioma surveillance, and that most registered cases appeared authentic despite some over-registration. Citing a separate report of an annual average of 33 compensated cases in 2001 to 2003, they concluded that 'false positives' in the registry do not explain the gap between registered and compensated cases.
• Limitations the authors state:
  • The specialists had access only to chart summaries and excerpts, not complete medical charts, which could have increased uncertainty in confirming diagnoses.
  • Under-registration (true cases missing from the registry) could not be estimated.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Cancer Registry, Mesothelioma, Pathology, Immunohistochemistry.

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