Factors affecting prognosis in patients diagnosed with epithelioid pleural mesothelioma who underwent surgery

Our plain-English summary of Factors affecting prognosis in patients diagnosed with epithelioid pleural mesothelioma who underwent surgery, by N. Akanil Fener, N. Ünver, H.N. Ürer, et al (Türk Göğüs Kalp Damar Cerrahisi Dergisi, 2026).

The study

• Authors: N. Akanil Fener, N. Ünver, H.N. Ürer, A.S. Koç, G. Oğuztürk, E.C. Seyhan, C.B. Sezen
• Journal: Türk Göğüs Kalp Damar Cerrahisi Dergisi
• Published: 2026;34(2):198-206
• Read it: PubMed · Publisher · Free full text

Abstract

Background: To examine how pathological variables affect prognosis in patients undergoing surgery for epithelioid pleural mesothelioma (PM).

Methods: The study examined 64 patients treated surgery for PM between January 2007 and October 2019, retrospectively. Clinicopathological variables including age, surgical procedure, tumor stage, and detailed histopathological features (nuclear atypia, mitotic count, necrosis, nuclear grading, and tumor grade) were evaluated. Overall survival was analyzed using Kaplan-Meier and Cox proportional hazards regression models. To avoid multicollinearity among interrelated pathological parameters, two separate multivariate Cox models were constructed.

Results: The 5-year survival rate was 8 percent, compared to 62 percent in the first year. Individuals 65 and older had no 5-year survival, whereas patients 65 and younger had a rate of 11 percent (p=0.046). In comparison to groups with mild and moderately high mitotic scores, those with a high mitotic score (p=0.019) had significantly lower median survival and 5-year survival rates. Variables (p<0.15) included in the univariate survival analysis were patients who 65 years and older, type of operation, mitosis, necrosis, tumor stage, nuclear grading, and grade of mesotheliomas. In multivariate analysis, high nuclear grade (Model 1: Hazard ratio [HR]=2.48, 95% confidence interval [CI]: 1.09-5.62, p=0.030) and high tumor grade (Model 2: HR=2.36, 95% CI: 1.05-5.31, p=0.037) were independently associated with worse overall survival.

Conclusion: Pathological grading, represented by either nuclear grade or tumor grade, is the strongest independent prognostic factor for survival in patients with epithelioid PM.

Copyright© 2026 The Author(s). Published by Galenos Publishing House on behalf of Turkish Society of Cardiovascular Surgery and Turkish Thoracic Surgery Association.

In plain English

This retrospective study reviewed 64 patients with epithelioid pleural mesothelioma who had surgery at a hospital in Istanbul, Türkiye, between January 2007 and October 2019. Of these, 53 had pleurectomy/decortication and 11 had extrapleural pneumonectomy. The study did not look at asbestos exposure. Tissue slides were re-examined: nuclear atypia and mitotic count were scored and added into a nuclear grade, which was then combined with necrosis to give a low or high tumor grade. Median overall survival was 22 months. The results give five-year survival as 6%; the abstract says 8%. No patient aged 65 or over survived five years. In two separate models also including age, surgery type and stage, high nuclear grade (hazard ratio 2.48, 95% CI 1.09-5.62) and high tumor grade (hazard ratio 2.36, 95% CI 1.05-5.31) were each linked with worse survival. In these models, age, surgery type and stage were not statistically significant. The authors concluded that these two grades were the most important factors. They noted the retrospective design, small numbers, multiple surgeons and missing performance-status data. Several of the article's numbers conflict.

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 of surgical patients (single-hospital case series analysed for survival using Kaplan-Meier and Cox regression)
• Who was studied: 64 patients with epithelioid pleural mesothelioma operated on between January 2007 and October 2019 at Yedikule Chest Diseases and Thoracic Surgery Training and Research Hospital, Istanbul. Of 107 operated patients, those excluded were 18 with biphasic mesothelioma, 2 with inaccessible files, 20 with inaccessible slides and 3 who died of complications within 2 weeks. The 64 were 51 men and 13 women, mean age 57.1 years. 53 had pleurectomy/decortication and 11 had extrapleural pneumonectomy.
• Exposure: Asbestos or other exposure was not assessed. The factors studied were age, gender, type of surgery, stage, and pathological features. Nuclear atypia and mitotic count scores were added to give a nuclear grade (I to III). Nuclear grade combined with the presence of necrosis gave a low or high tumor grade.
• Main results:
  • All 64 patients: median overall survival 22 months (Table 3, which labels it median; the results text calls it 'average'); 5-year survival 6% and 2-year survival 64% (the abstract instead reports 8% at 5 years and 62% at 1 year).
  • Patients under 65 (n=44): median survival 25 months, 5-year survival 11% (p=0.046). Patients 65 and older (n=20): no 5-year survival; median 16 months per Table 3.
  • 5-year survival was 5% after decortication and 18 (unit not printed) after extrapleural pneumonectomy (p=0.038). Table 3 gives median survival of 36 months for EPP and 19 months for PD. The authors attributed the EPP advantage to patient selection bias and stage differences.
  • Low mitotic count group: 5-year survival 13%, median survival 31 months in the text (37 months in Table 3). Intermediate and high mitotic groups: 0% 5-year survival (p=0.002).
  • Nuclear grade I (n=26): 5-year survival 19%, median 32 months. Nuclear grades II and III: 0% 5-year survival (p=0.005).
  • Necrosis present (n=8): median survival 12 months. Necrosis absent: 5-year survival 8%, median 24 months (p=0.048).
  • Low-grade mesotheliomas (n=49): median survival 25 months, 5-year survival 10.2% (p=0.008). High-grade mesotheliomas (n=15): no 5-year survival.
  • Histological pattern (tubulopapillary, micropapillary, solid, etc.) was not statistically significantly related to survival.
  • Multivariate Model 1: high nuclear grade (grade III) was independently associated with poorer overall survival, HR 2.48 (95% CI 1.09-5.62), p=0.030.
  • Multivariate Model 2, with tumor grade replacing nuclear grade: high tumor grade was independently associated with worse survival, HR 2.36 (95% CI 1.05-5.31), p=0.037.
  • In the multivariate models, age, surgical procedure and stage were not statistically significant; the authors called them borderline. In Model 1 (Table 4): age HR 1.72 (0.98-3.01), p=0.058; surgical procedure HR 1.95 (0.92-4.12), p=0.076; stage HR 1.89 (0.97-3.68), p=0.061.
• The authors' conclusion: The authors concluded that, although age, resection type, stage, nuclear atypia, mitoses, necrosis and grade were linked to survival, the most important factors were nuclear grade and tumor grade. They described these as cost-effective because they can be assessed on routine H&E slides.
• Limitations the authors state:
  • Retrospective design, operations by more than one surgeon, small number of patients, and recurrences could not be analysed.
  • No information on patients' ECOG performance status, which the authors call a significant limitation and source of bias.
  • Completion of planned adjuvant chemotherapy and/or radiotherapy could not be reliably assessed.
  • Better survival after extrapleural pneumonectomy may reflect patient selection bias and stage differences.
  • Results reflect a pre-immunotherapy era.
  • Small numbers and uneven distribution across histological patterns may explain the lack of a pattern-survival association.

Topics

Medical terms in this study, explained in our Lexicon: Prognosis, Epithelioid, Pleural Mesothelioma, Nuclear Atypia, Mitotic Count, Necrosis, Nuclear Grading, Overall Survival.

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