Mesothelioma Diagnoses on Asbestos Workers’ Death Certificates Often Cannot Be Confirmed

By: Ray Harris

Updated October 26, 2026

Many occupational cohort studies use the cause of death recorded on death certificates to assess cancer mortality. Those records can be inaccurate.1 This is particularly relevant for mesothelioma.

A 2018 study by Boffetta and colleagues illustrates the potential for misclassifying mesothelioma. The authors “searched medical and pathology records and specimens for 127 workers from a textile-asbestos factory in Italy who died during 1963–2013 with a diagnosis of pleural or peritoneal neoplasm or mesothelioma on death certificate, to confirm the diagnosis with immunohistochemistry markers.” The authors were able to confirm only a small proportion of mesothelioma diagnoses: “The diagnosis of mesothelioma was histologically confirmed for 35 cases (27.6%); 5 cases were classified as non-mesothelioma (3.9%), for 33 cases a mention of mesothelioma was found on record but no sufficient material was available for revision (26.0%); no records were available for 54 cases (death-certificate-only 42.5%).”2

This “study shows that for a relatively large proportion of members of historical cohorts of asbestos workers, the information on pleural or peritoneal cancer/mesothelioma reported on death certificates cannot be validated through medical or pathology records, and even less so with review of pathology material.”3

Notes

  1. See, e.g., Tan, Misclassification of the Actual Causes of Death and Its Impact on Analysis: A Case Study in Non-Small Cell Lung Cancer, 134 Lung Cancer 16, 16 (2019).
  2. Boffetta, Righi, Ciocan, Pelucchi, La Vecchia, Romano, Papotti & Pira, Validation of the Diagnosis of Mesothelioma and BAP1 Protein Expression in a Cohort of Asbestos Textile Workers from Northern Italy, 29 Annals Oncology 484, 484 (2018).
  3. Id. at 487.