Clinically important associations of pleurodesis success in malignant pleural effusion: Analysis of the TIME1 data set

Our plain-English summary of Clinically important associations of pleurodesis success in malignant pleural effusion: Analysis of the TIME1 data set, by R.M. Mercer, J. Macready, H. Jeffries, et al (Respirology, 2020).

The study

• Authors: R.M. Mercer, J. Macready, H. Jeffries, N. Speck, N.I. Kanellakis, N.A. Maskell, J. Pepperell, T. Saba, A. West, N. Ali, J.P. Corcoran, R.J. Hallifax, I. Psallidas, R. Asciak, M. Hassan, R.F. Miller, N.M. Rahman
• Journal: Respirology
• Published: 2020;25(7):750-755
• Cited by: 16 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background And Objective: Chemical pleurodesis is performed for patients with MPE with a published success rate of around 80%. It has been postulated that inflammation is key in achieving successful pleural symphysis, as evidenced by higher amounts of pain or detected inflammatory response. Patients with mesothelioma are postulated to have a lower rate of successful pleurodesis due to lack of normal pleural tissue enabling an inflammatory response.

Methods: The TIME1 trial data set, in which pleurodesis success and pain were co-primary outcome measures, was used to address a number of these assumptions. Pain score, systemic inflammatory parameters as a marker of pleural inflammation and cancer type were analysed in relation to pleurodesis success.

Results: In total, 285 patients were included with an overall success rate of 81.4%. There was a significantly higher rise in CRP in the Pleurodesis Success group compared with the Pleurodesis Failure group (mean difference: 19.2, 95% CI of the difference: 6.2-32.0, P = 0.004) but no significant change in WCC. There was no significant difference in pain scores or analgesia requirements between the groups. Patients with mesothelioma had a lower rate of pleurodesis success than non-mesothelioma patients (73.3% vs 84.9%, χ2 = 5.1, P = 0.023).

Conclusion: Change in CRP during pleurodesis is associated with successful pleurodesis but higher levels of pain are not associated. Patients with mesothelioma appear less likely to undergo successful pleurodesis than patients with other malignancies, but there is still a significant rise in systemic inflammatory markers. The mechanisms of these findings are unclear but warrant further investigation.

© 2019 Asian Pacific Society of Respirology.

In plain English

This was a retrospective analysis of TIME1 trial data on patients with malignant pleural effusion (cancer-related fluid in the space around the lung) treated with talc pleurodesis, a procedure to seal that space. The study did not examine asbestos exposure. Of 320 patients enrolled, 285 were analysed; pleurodesis succeeded at 3 months in 81.4% (232/285). CRP, a blood marker of inflammation, rose more when pleurodesis succeeded (mean rise 46.2 mg/L) than when it failed (27.1 mg/L), a mean difference of 19.2 (95% CI 6.2 to 32.0, P = 0.004). That difference stayed statistically significant only in patients treated at thoracoscopy. Pain scores did not differ significantly between groups. Mesothelioma patients had a lower success rate than patients with other cancers (73.3% vs 84.9%, P = 0.023), despite a higher CRP rise. When patients with unexpandable lung were excluded, the mesothelioma difference was not statistically significant (74.7% vs 84.9%, P = 0.058). The authors concluded that patients with a greater inflammatory response were more likely to have successful pleurodesis, and that pain did not appear to affect success.

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 analysis of prospectively collected data from a randomized controlled trial (TIME1)
• Who was studied: Patients with malignant pleural effusion enrolled in the TIME1 trial (320 enrolled, 285 analysed), treated at UK hospitals; dates not given in this article
• Exposure: Talc pleurodesis, given either at thoracoscopy or as talc slurry through a chest drain. Patients were randomized to a 24F or 12F chest drain and to opiate or NSAID pain relief. No asbestos or fiber exposure was studied.
• Main results:
  • Overall pleurodesis success at 3 months was 81.4% (232/285 patients)
  • Mean CRP change was 46.2 mg/L (95% CI 38.5 to 53.9) in the Pleurodesis Success group and 27.1 mg/L in the Pleurodesis Failure group; mean difference 19.2 (95% CI of the difference 6.2 to 32.0), P = 0.004
  • The higher CRP change in the success group stayed statistically significant only in the thoracoscopy arm, not in the non-thoracoscopy arm
  • Mean white cell count change was higher in the success group (2.35) than the failure group (1.79), a mean difference of 0.56 (95% CI of the difference −0.33 to 1.45, P = 0.214), which was not statistically significant
  • Average pain score (VAS) over the first 24 hours was 23.6 mm in the success group and 21.4 mm in the failure group (P = 0.42), not a significant difference
  • Patients with mesothelioma had a lower pleurodesis success rate than non-mesothelioma patients: 73.3% vs 84.9%, P = 0.023
  • After excluding patients with unexpandable lung (87 with mesothelioma and 139 non-mesothelioma remaining), success was 74.7% in mesothelioma vs 84.9% in other cancers, P = 0.058, not statistically significant
  • CRP change was higher in mesothelioma patients (58.9 mg/L) than in non-mesothelioma patients (26.8 mg/L); mean difference 32.1 mg/L (95% CI of the difference 19.1 to 45.2), P less than 0.001
  • Unexpandable lung was more common in the Pleurodesis Failure group (26.1%, 12 of 46) than in the Success group (12.3%, 26 of 211), P = 0.017
• The authors' conclusion: The authors concluded that patients with a greater inflammatory response, shown by a rise in CRP, are more likely to have successful pleurodesis, and that patients with MPE due to mesothelioma appear to respond differently to pleurodesis than those with other cancers
• Limitations the authors state:
  • The authors assumed that blood (serum) CRP levels reflect inflammation inside the pleural space
  • No specific CRP cut-off value was found that could predict pleurodesis success or be used in clinical practice
  • The CRP finding was not significant in the non-thoracoscopy arm, which was a much smaller group
  • The difference in unexpandable lung between mesothelioma and other patients was not significant, likely due to small numbers
  • The rate of unexpandable lung in mesothelioma patients probably underestimates the true rate, because patients with known unexpandable lung would not be offered pleurodesis
  • The authors assumed the baseline pain-relief effects were equivalent between groups

Topics

The National Library of Medicine indexes this study under subjects our site covers: Talc and vermiculite.

Medical terms in this study, explained in our Lexicon: Pleurodesis, Pleural Effusion, Inflammation, Mesothelioma.

Related studies

• Survival in patients with malignant pleural effusion undergoing talc pleurodesis — M. Hassan, R.M. Mercer, et al. (2019)
• Success rate of medical thoracoscopy and talc pleurodesis in malignant pleurisy: A single-centre experience — J. Leemans, C. Dooms, et al. (2018)
• Indwelling pleural catheter versus talc pleurodesis for malignant pleural effusion: a meta-analysis — M. Yeung, E.W. Loh, et al. (2020)
• Predictors of clinical use of pleurodesis and/or indwelling pleural catheter therapy for malignant pleural effusion — E.T.H. Fysh, S. Bielsa, et al. (2015)
• Tumor type influences the effectiveness of pleurodesis in malignant effusions — S. Bielsa, P. Hernández, et al. (2011)
• Can serum inflammatory parameters estimate outcome of pleurodesis in mesothelioma? — M. Bilgin, L. Hasdiraz, et al. (2007)

Browse more research in Respirology, or return to medical research.