Mesothelioma in a developing country: a retrospective analysis of the diagnostic process

Our plain-English summary of Mesothelioma in a developing country: a retrospective analysis of the diagnostic process, by P.H.P. Gregório, R.M. Terra, L.P. Lima, et al (Jornal Brasileiro de Pneumologia, 2022).

The study

• Authors: P.H.P. Gregório, R.M. Terra, L.P. Lima, P.M. Pêgo-Fernandes
• Journal: Jornal Brasileiro de Pneumologia
• Published: 2022;48(5):e20220064
• Language: Portuguese
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Objective: To evaluate the process of diagnosing patients with malignant pleural mesothelioma (MPM) at a tertiary care hospital.

Methods: This was a retrospective study involving patients referred to a tertiary-care cancer center in Brazil between 2009 and 2020. The diagnostic process was divided into four steps: onset of symptoms, referral to a specialist visit, histopathological diagnosis, and beginning of treatment. The intervals between each phase and the factors for delays were evaluated. Data including clinical status, radiological examinations, staging, treatment modalities, and survival outcomes were collected.

Results: During the study period, 66 patients (mean age = 64 years) were diagnosed with MPM and underwent treatment. Only 27 (41%) of the patients had knowledge of prior exposure to asbestos. The median number of months (IQR) between the onset of symptoms and the first specialist visit, between the specialist visit and histopathological characterization, and between definite diagnosis and beginning of treatment was, respectively, 6.5 (2.0-11.4), 1.5 (0.6-2.1), and 1.7 (1.2-3.4). The knowledge of prior asbestos exposure was associated with a shorter time to referral to a specialist (median: 214 vs. 120 days; p = 0.04). A substantial number of nondiagnostic procedures and false-negative biopsy results (the majority of which involved the use of Cope needle biopsy) were found to be decisive factors for the length of waiting time. The mean overall survival was 11.9 months.

Conclusions: The unfamiliarity of health professionals with MPM and the patient's lack of knowledge of prior asbestos exposure were the major factors to cause a long time interval between the onset of symptoms and beginning of treatment. An overall survival shorter than 1 year is likely to have been due to the aforementioned delays.

In plain English

This retrospective study reviewed the medical records of 66 patients with malignant pleural mesothelioma treated at a public cancer center in São Paulo, Brazil, between July 2009 and December 2020. The authors timed each step from first symptoms to treatment. Patients' mean age at diagnosis was 64.3 years. Only 27 (41%) had knowledge of prior asbestos exposure in their records. The article gives no fiber types or jobs. Patients waited a median of 6.5 months from symptoms to a specialist visit, then a median of 1.5 months to a tissue diagnosis, and 1.7 months more to treatment. The median time to referral was 214 days for patients unaware of asbestos exposure and 120 days for those aware (p = 0.04). Cope needle biopsies done at the center missed the cancer in 8 of 14 patients, compared with 1 of 23 surgical biopsies. Overall survival after diagnosis was 11.9 months (95% confidence interval 8.4 to 15.3 months), which the article's abstract calls the mean. The authors concluded that patients' unawareness of asbestos exposure and health professionals' unfamiliarity with the disease threaten care in Brazil. They noted that patient-reported histories may be inaccurate.

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: Retrospective study (review of medical records) at a single cancer center
• Who was studied: 66 patients with a histopathological diagnosis of malignant pleural mesothelioma treated at a public tertiary-care cancer center in São Paulo, Brazil, July 2009 to December 2020; 52 men and 14 women; mean age 64.3 years at diagnosis
• Exposure: Whether the patient had knowledge of prior asbestos exposure, as recorded in the medical records (27 yes, 39 no). No fiber types, products, jobs or doses are given.
• Main results:
  • Of the 66 patients, 30 (45%) were current smokers and 11 (17%) were former smokers
  • Epithelioid mesothelioma made up 88% of cases (58 of 66)
  • Median time from onset of symptoms to first specialist visit was 6.5 months (interquartile range 2.0 to 11.4 months)
  • Median time to referral was 214 days in the group with no knowledge of prior asbestos exposure and 120 days in the group with that knowledge (p = 0.04)
  • Before the specialist visit, the number of procedures was not significantly related to the number of days to referral (rho = minus 0.07; p = 0.68)
  • Median time to adequate histopathological characterization was 1.5 months (0.6 to 2.1)
  • Among 40 patients biopsied after referral, 8 of the 14 Cope needle biopsies were false-negative (57.1%), compared with 1 of the 23 surgical biopsies (4.3%)
  • Pleural fluid cytology before biopsy was negative in 15 of 26 patients tested (57.7%)
  • Median time from diagnosis to start of treatment was 1.7 months (1.2 to 3.4)
  • Only 15 patients had major surgery: extended pleuropneumonectomy in 11 and extended pleural decortication in 4
  • Overall survival time after diagnosis was 11.9 months (95% confidence interval 8.4 to 15.3) for the 66 patients
  • The article's abstract describes the 11.9-month figure as the mean overall survival
• The authors' conclusion: The authors concluded that patients' lack of awareness of previous asbestos exposure and health professionals' unfamiliarity with the disease threaten the capacity to offer the best available treatment for this cancer in Brazil.
• Limitations the authors state:
  • Findings on care before referral may be inaccurate because they rely on patients' reports of their past medical history
  • Survival could not be compared by histological subtype because there were few sarcomatoid and biphasic cases
  • Only a few image-guided biopsies were analyzed

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, Pleural Mesothelioma, Staging, Asbestos Exposure, Biopsy, Needle Biopsy, Overall Survival.

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