Amount of Epithelioid Differentiation Is a Predictor of Survival in Malignant Pleural Mesothelioma

Our plain-English summary of Amount of Epithelioid Differentiation Is a Predictor of Survival in Malignant Pleural Mesothelioma, by W.T. Vigneswaran, D.Y. Kircheva, V. Ananthanarayanan, et al (The Annals of Thoracic Surgery, 2017).

The study

• Authors: W.T. Vigneswaran, D.Y. Kircheva, V. Ananthanarayanan, S. Watson, Q. Arif, A.D. Celauro, H.L. Kindler, A.N. Husain
• Journal: The Annals of Thoracic Surgery
• Published: 2017;103(3):962-966
• Cited by: 41 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Macroscopic complete surgical resection with adjuvant chemotherapy can provide a survival advantage in patients with malignant pleural mesothelioma (MPM). Patients with nonepithelioid histology are largely excluded from such radical operations even though they might benefit. The degree of epithelioid differentiation varies in biphasic histology. We report the outcomes of pleurectomy and decortication and the effect of epithelioid differentiation on overall survival of patients with MPM.

Methods: This report is based on the outcomes of 144 patients who underwent pleurectomy and decortication at a single institution between 2008 and 2015. The variables assessed were age, gender, histology, and pathologic T and N stage. No patients with pure sarcomatoid histology were included. Two independent pathologists estimated the percentage of epithelioid histology. A Cox regression model was used to identify significant predictors of survival. The Kaplan-Meier method was used to summarize overall and subgroup survival.

Results: Included were 116 men and 28 women with a median age of 69 years (range, 43 to 88 years). The 2-year survival from pleurectomy and decortication was 20%. Median survival overall was 13.34 months and was 20.1 months for the 100% epithelioid subgroup (n = 77), 11.8 months for the 51% to 99% epithelioid subgroup (n = 39), and 6.62 months for the less than 50% epithelioid subgroup (n = 28). The amount of epithelioid differentiation was a significant predictor of survival (p < 0.001). Differences in survival based on the T, but N stage, were not statistically significant.

Conclusions: The percentage of epithelioid differentiation is an independent predictor of survival in MPM and should be taken into careful consideration when recommending surgical treatment for patients with biphasic MPM.

Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

In plain English

This retrospective study reviewed 144 patients with malignant pleural mesothelioma who had an operation called pleurectomy and decortication at the University of Chicago between March 2008 and September 2015. There were 116 men and 28 women, with a median age of 69. Patients with purely sarcomatoid tumors were not included. Two pathologists estimated what percentage of each tumor was the epithelioid cell type. The article does not report on asbestos exposure. Two-year survival after surgery was 20%, and median survival was 13.34 months. Median survival was 20.1 months in the 77 patients whose tumors were fully epithelioid, 11.8 months in the 39 with 51% to 99% epithelioid tumors, and 6.62 months in the 28 with less than 50%. The amount of epithelioid differentiation was a significant predictor of survival (p less than 0.001). Survival differences by tumor (T) stage and by lymph node (N) stage were not statistically significant. The authors concluded that the epithelioid percentage in mixed (biphasic) tumors affects survival and should be considered when selecting patients for treatment. They said they found no cutoff point and that larger studies are needed.

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 review of a single-center surgical cohort (survival analysis)
• Who was studied: 144 consecutive patients with biopsy-proven malignant pleural mesothelioma (epithelioid or biphasic; no pure sarcomatoid) who underwent pleurectomy and decortication at University of Chicago Medicine, March 2008 to September 2015; 116 men and 28 women, median age 69 years (range 43 to 88)
• Exposure: No asbestos exposure was studied. The factor studied was the percentage of epithelioid differentiation in the tumor, from 100% (pure epithelioid) through 1% to 99% (biphasic), estimated by two pathologists.
• Main results:
  • All patients: two-year survival after extended pleurectomy and decortication was 20%; median survival was 13.34 months
  • Pure epithelioid tumors (77 patients, 53.5%): median survival 20.1 months
  • 51% to 99% epithelioid tumors (39 patients, 27.1%): median survival 11.8 months
  • Less than 50% epithelioid tumors (28 patients, 19.4%): median survival 6.62 months
  • Epithelioid differentiation was a significant and independent predictor of survival (p less than 0.001)
  • In the multivariate Cox model, the hazard ratio for epithelioid was 0.364 (p = 0.00154) and for adjuvant chemotherapy was 0.457 (p = 0.00403); no confidence intervals were given
  • When biphasic patients were divided into 25% steps, survival differences were reported as significant, except that there was no statistically significant difference between the less than 25% and the 51% to 75% subgroups
  • T1 stage appeared to have better survival than other T stages, but this was not statistically significant
  • No significant survival difference between patients without lymph node disease and those with nodal involvement
• The authors' conclusion: The authors concluded that the percentage of epithelioid differentiation in biphasic tumors has an effect on survival. They said it should be considered in developing a prognostic scoring system to select patients for multimodality treatment, and that their findings need validation.
• Limitations the authors state:
  • No cutoff point for epithelioid differentiation was identified
  • The lack of a significant difference between some subgroups may reflect the small numbers of patients
  • The findings need validation in a larger cohort

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: Epithelioid, Pleural Mesothelioma, Surgical Resection, Chemotherapy, Histology, Biphasic Mesothelioma, Overall Survival, Sarcomatoid.

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• Predictors of long-term survival following radical surgery for malignant pleural mesothelioma — A. Nakas, D. Waller (2014)
• Combined grade and nuclear grade are prognosis predictors of epithelioid malignant peritoneal mesothelioma: a multi-institutional retrospective study — N. Benzerdjeb, P. Dartigues, et al. (2021)
• A nuclear grading system is a strong predictor of survival in epitheloid diffuse malignant pleural mesothelioma — K. Kadota, K. Suzuki, et al. (2012)
• Malignant Peritoneal Mesothelioma: National Practice Patterns, Outcomes, and Predictors of Survival — V. Verma, R.L. Sleightholm, et al. (2018)

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