Peritoneal mesotheliomas in Danish women:

Abstract

An unexpectedly large number of peritoneal mesotheliomas among women was reported to the Danish Cancer Registry during the years 1960 through 1985. In a case-control study, we tested whether this was due to diagnostic misclassification or to direct exposure of the peritoneal membranes to talc during abdominal surgery. Tissue specimens were available from 96 reported peritoneal mesotheliomas; 35 cases (37%) were regarded as verified mesotheliomas, and 33 (34%) as possible mesotheliomas. Information on any intraabdominal surgery was obtained from the hospital records of these 68 cases and for 206 controls with a cancer of the uterine corpus or pancreas. No association was seen between peritoneal mesotheliomas and abdominal surgery performed more than 25 years prior to cancer diagnosis (odds ratio, 0.83; 95% confidence interval, 0.35-1.94). CONCLUSION. Misclassification of other cancers was the reason for the observed excess of peritoneal mesotheliomas.

Incidence rates of malignant mesothelioma in Denmark and predicted future number of cases among men

“…In a Danish study about 30% of the peritoneal mesothelioma cases among women were found to be misclassified ovarian or gastrointestinal tumors (23).…”

“…However some misclassification of mesothelioma cases has occurred (23), and this misclassification complicates the interpretation of the results. …”

Incidence trends of mesothelioma in Norway, 1965–1999

“…The diagnosis of peritoneal mesothelioma is difficult, both clinically and histopathologically, and incomplete biopsy material may lead to uncertainty. In a study of peritoneal mesotheliomas in Danish women, about 30% of the peritoneal mesothelioma cases were found to be misclassified ovarian or gastrointestinal tumors 29. Misclassification may probably also occur the other way around, although the extent of this has not been described.…”

Occupational Exposure to Asbestos and Ovarian Cancer: A Meta-analysis

“…Nielsen et al (1994), based on a large series of peritoneal mesotheliomas, estimated that 16% of cases were misdiagnosed as ovarian cancer cases. Assuming that a similar proportion of peritoneal mesotheliomas are misclassified as ovarian cancer cases, we evaluated the effect of misclassification on the overall pooled SMR estimate by removing 20% of ovarian cancer cases from every study and repeating the meta-analysis.…”