Malignant pleural mesothelioma: diagnostic value of medical thoracoscopy and long-term prognostic analysis

Our plain-English summary of Malignant pleural mesothelioma: diagnostic value of medical thoracoscopy and long-term prognostic analysis, by L.L. Xu, Y. Yang, Z. Wang, et al (BMC Pulmonary Medicine, 2018).

The study

• Authors: L.L. Xu, Y. Yang, Z. Wang, X.J. Wang, Z.H. Tong, H.Z. Shi
• Journal: BMC Pulmonary Medicine
• Published: 2018;18(1):56
• Cited by: 15 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Malignant pleural mesothelioma (MPM) is marked by its difficult diagnosis and poor prognosis. Medical thoracoscopy (MT) is an effective and safe procedure for the diagnosis of exudative pleural effusions and many factors associated with poor prognosis of MPM. We conducted this study to investigate the value of MT for diagnosing of MPM and to identify prognostic factors for MPM patients.

Methods: From July 2005 through June 2014, a total of 833 patients with undiagnosed pleural effusions underwent MT and pleural biopsies were taken. Clinical data of all patients with MPM were retrospectively analyzed, and those with complete follow-up data were analyzed for prognostic factors.

Results: Eventually, MPM was the final diagnosis in 40 patients. Diagnostic efficiency of MT for MPM was 87.5%, since diagnosis of MPM failed to be established in 5 patients during the initial MT. Median survival was 17.1 mo (95% confidence interval: 13.6-20.7 mo). MT findings of pleural adhesion and plaques were adverse prognostic factors for MPM. In addition, old age, male gender, smoking history, histological type, poor staging, no treatment, low total protein level in pleural fluid, and computed tomographic findings such as pulmonary consolidation or infiltration, mediastinal lymphopathy, pulmonary mass or nodules, and pleural nodularity were also poor prognostic factors for MPM.

Conclusions: MT is safe with a high positive rate in the diagnosis of MPM, and pleural adhesion and plaques seen under MT may be the adverse prognostic factors for MPM. Multiple clinical characteristics can affect the survival of MPM patients.

In plain English

This retrospective study at Beijing Chaoyang Hospital in China looked at 833 patients who had pleural effusions (fluid around the lung) of unknown cause. Between July 2005 and June 2014 they underwent medical thoracoscopy, a procedure for viewing the chest lining and taking biopsies. Forty were finally diagnosed with malignant pleural mesothelioma. In 35 of them the diagnosis came from the first thoracoscopy, which the authors reported as a diagnostic efficiency of 87.5%. Survival was analyzed for the 33 patients followed until death. Their median survival was 17.1 months (95% confidence interval 13.6 to 20.7). Shorter survival was associated with several factors: pleural adhesion and pleural plaques seen at thoracoscopy, age 70 or over, male sex, smoking history, more advanced stage, no treatment, low protein in the pleural fluid, and several CT findings. Histological type was also associated with survival. The authors concluded that these may be adverse prognostic factors. They noted the small sample and possible selection bias. They also noted that none of the 33 patients analyzed for survival had surgery. The article did not report the patients' asbestos exposure.

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 cohort study of hospital records (diagnostic yield and survival analysis)
• Who was studied: 40 patients with malignant pleural mesothelioma (20 men, 20 women; median age 62, range 40 to 78). They came from 833 patients with undiagnosed pleural effusions who underwent medical thoracoscopy at Beijing Chaoyang Hospital, China, from July 2005 to June 2014. 33 were followed until death and analyzed for survival; 7 were lost to follow-up.
• Exposure: This is not an asbestos exposure study. The article examined medical thoracoscopy as a way to diagnose mesothelioma and looked at clinical factors related to survival. It did not report the patients' asbestos exposure.
• Main results:
  • 35 of the 40 mesothelioma patients were diagnosed from biopsies taken at the first thoracoscopy, which the authors reported as a diagnostic efficiency of 87.5%. The other 5 were diagnosed later by other procedures.
  • Among the 33 patients followed until death, median survival was 17.1 months (95% confidence interval 13.6 to 20.7 months), with a range of 1.0 to 69.9 months.
  • No patient was diagnosed at stage I. 9 were at stage II and the rest at stage III or IV. In Table 2, median survival was 28.4 months at stage II, 17.1 at stage III and 3.0 at stage IV (hazard ratio 21.042, 95% CI 6.156 to 71.923, P less than 0.001).
  • Pleural adhesion and pleural plaques seen at thoracoscopy were associated with shorter survival. Adhesion: median 5.4 months for the 6 patients with it vs 19.1 for the 24 without (hazard ratio 0.277, 95% CI 0.097 to 0.788, P = 0.016). Plaques: median 13.0 months for the 12 patients with them vs 19.1 for the 18 without (hazard ratio 0.387, 95% CI 0.170 to 0.879, P = 0.023).
  • Pleural nodules (P = 0.985), pleural hyperemia (P = 0.246) and pleural edema (P = 0.814) seen at thoracoscopy were not related to survival.
  • Three general factors were associated with shorter survival. Age 70 or over: median 5.1 vs 17.4 months (HR 1.81, 95% CI 1.165 to 2.813, P = 0.008). Sex: median 13.0 months for men vs 20.0 for women (HR 0.346, 95% CI 0.142 to 0.844, P = 0.020). Smoking history: median 5.4 vs 20.0 months (HR 6.752, 95% CI 2.418 to 18.855, P less than 0.001).
  • Histological type was associated with survival (HR 0.095, 95% CI 0.031 to 0.293, P less than 0.001). Treatment was also associated with survival: patients given no therapy had a median of 3.0 months vs 20.0 with chemotherapy (HR 0.087, 95% CI 0.021 to 0.359, P = 0.001).
  • Pleural fluid total protein below 40 g/L was associated with shorter survival (median 3.2 vs 19.1 months; HR 0.131, 95% CI 0.048 to 0.359, P less than 0.001). Pleural fluid LDH was not (P = 0.535).
  • Four CT findings were associated with shorter survival: pulmonary consolidation or infiltration (HR 0.191, 95% CI 0.066 to 0.547, P = 0.002), mediastinal lymphopathy (HR 0.230, 95% CI 0.080 to 0.661, P = 0.006), pulmonary mass or nodules (HR 0.123, 95% CI 0.031 to 0.486, P = 0.003) and pleural nodularity (HR 0.340, 95% CI 0.120 to 0.964, P = 0.043). Pulmonary atelectasis (P = 0.753) and pleural thickening (P = 0.412) were not.
• The authors' conclusion: The authors concluded that medical thoracoscopy is safe and has a high positive rate in diagnosing malignant pleural mesothelioma. They concluded that pleural adhesion and plaques seen at thoracoscopy may probably be adverse prognostic factors. They named other possible poor prognostic factors: old age, male sex, smoking history, histological type, poor staging, no treatment, low pleural fluid protein and certain CT findings. They called for larger prospective studies.
• Limitations the authors state:
  • The sample was small: 40 patients, with only 33 analyzed for prognosis. The authors stated this increases the chance that the proposed poor prognostic factors are false findings.
  • There were no control groups (patients with other cancers or benign pleural disease), so the sensitivity and specificity of thoracoscopy for mesothelioma could not be calculated.
  • None of the 33 patients analyzed for survival underwent surgery, so the relationship between surgery and survival could not be analyzed.
  • This retrospective study has potential selection bias.
  • The link between no treatment and poor survival may simply reflect that untreated patients had advanced disease and poor overall condition.

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: Pleural Mesothelioma, Medical Thoracoscopy, Prognosis, Pleural Effusion, Median Overall Survival, confidence interval, Staging, Consolidation.

Related studies

• Diagnostic value of medical thoracoscopy in malignant pleural effusion — Y.B. Wu, L.L. Xu, et al. (2017)
• Diagnostic value of medical thoracoscopy in pleural disease: a 6-year retrospective study — F.X. Blanc, K. Atassi, et al. (2002)
• Diagnostic performance and safety of image-guided pleural biopsy and medical thoracoscopy for undiagnosed exudative pleural effusion: a systematic review and network meta-analysis — S. Lyu, Z. Zheng, et al. (2026)
• Outcomes and complications following medical thoracoscopy — F.J. Brims, M. Arif, et al. (2012)
• Success rate of medical thoracoscopy and talc pleurodesis in malignant pleurisy: A single-centre experience — J. Leemans, C. Dooms, et al. (2018)
• Outcome of patients diagnosed with fibrinous pleuritis after medical thoracoscopy — M. Metintas, G. Ak, et al. (2012)

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