Extrapleural pneumonectomy in the treatment of epithelioid malignant pleural mesothelioma: novel prognostic implications of combined N1 and N2 nodal involvement based on experience in 529 patients

Our plain-English summary of Extrapleural pneumonectomy in the treatment of epithelioid malignant pleural mesothelioma: novel prognostic implications of combined N1 and N2 nodal involvement based on experience in 529 patients, by D.J. Sugarbaker, W.G. Richards, R. Bueno (Annals of Surgery, 2014).

The study

• Authors: D.J. Sugarbaker, W.G. Richards, R. Bueno
• Journal: Annals of Surgery
• Published: 2014;260(4):577-80; discussion 580-2
• Cited by: 92 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Objective: We review our 24-year experience with extrapleural pneumonectomy (EPP) in the treatment of epithelioid malignant pleural mesothelioma (MPM).

Background: Recent publications, particularly the MARS (Mesothelioma and Radical Surgery) feasibility study by Treasure et al, have questioned the safety and efficacy of EPP for MPM.

Methods: An institutional review board-approved, prospective, single-center database was retrospectively reviewed. Descriptive statistics and Kaplan-Meier analysis of overall survival are reported.

Results: From 1988 to 2011, a total of 529 patients with epithelioid MPM underwent complete resection by EPP as part of a multimodality strategy. Among these, 131 (25%) were women, and the median age was 59 (range, 17-79) years. Median postoperative hospital stay was 10 (range, 1-101) days. Twenty-six patients (5%) experienced 30-day or in-hospital mortality. Median overall survival was 18 months, with 1-, 3-, 5-, and 10-year survival rates of 67%, 28%, 14%, and 4%, respectively. Outcome by pathologic lymph node status (N, median overall survival) was N0: 224, 26 months; N1: 118, 17 months; N2: 181, 13 months; N3: 5, 7 months; Nx: 1, not evaluable.

Conclusions: EPP has evolved as an effective method for macroscopic complete resection. This study confirms that lymph node status is significantly correlated with overall survival in patients with epithelioid MPM undergoing EPP and suggests that those with simultaneous involvement of N1 and N2 stations are at increased risk. This observation underscores the need for thorough staging of both N1 and N2 stations and has implications for revision of MPM staging criteria.

In plain English

This was a retrospective review of a single-center database at Brigham and Women's Hospital in Boston. The authors studied 529 patients with the epithelioid type of malignant pleural mesothelioma who had all visible tumor removed by extrapleural pneumonectomy, which removes the lung, pleura, pericardium and diaphragm, between 1988 and 2011. The study did not examine asbestos exposure. Twenty-six patients (5%) died within 30 days or in hospital, and 44 of 529 (8%) died within 90 days. Median overall survival was 18 months. Survival at 1, 3, 5 and 10 years was 67%, 28%, 14% and 4%. Median survival was 26 months for patients without lymph node spread (N0), 17 months for N1 and 13 months for N2. Patients with both N1 and N2 node spread did worse than those with either alone. Women and patients aged 59 or younger had longer median survival. The authors concluded that combined N1 and N2 involvement carries a worse outlook, with implications for revising mesothelioma staging. They noted the biases of a retrospective, single-institution review.

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 patient registry (data collected retrospectively before 2005 and prospectively after), with Kaplan-Meier survival analysis
• Who was studied: 529 patients with epithelioid malignant pleural mesothelioma who underwent extrapleural pneumonectomy at Brigham and Women's Hospital, Boston, from 1988 to 2011. 131 (25%) were women, and the median age was 59 (range 17 to 79).
• Exposure: Not an asbestos exposure study. What was studied was a treatment: removal of all visible tumor (macroscopic complete resection) by extrapleural pneumonectomy (EPP), followed by additional local and systemic treatment intended to control microscopic disease. Outcomes were analyzed by lymph node status and other factors.
• Main results:
  • Median overall survival for the whole cohort of 529 patients was 18 months.
  • Survival rates for the whole cohort were 67% at 1 year, 28% at 3 years, 14% at 5 years and 4% at 10 years.
  • Twenty-six patients (5%) died within 30 days of surgery or during their postoperative hospital stay.
  • The 90-day mortality rate was 8% (44 of 529 patients).
  • Median overall survival by lymph node status (number of patients, median survival): N0, 224 patients, 26 months; N1, 118 patients, 17 months; N2, 181 patients, 13 months; N3, 5 patients, 7 months; Nx, 1 patient, not evaluable.
  • Of patients with N2 involvement, 136 (26%) also had N1 involvement and 45 (9%) had N2 involvement only. Patients with N2-only or N1-only spread had similar, more favorable survival than patients with both N2 and N1 spread.
  • Age and sex were significantly related to survival. Median overall survival was 28 months for women (131) and 17 months for men (398), P = 0.0005. It was 20 months for patients aged 59 or younger (276) and 16 months for those older than 59 (253), P = 0.0009. Tumor side and hospital length of stay (P = 0.1263) were not significantly related to survival.
• The authors' conclusion: The authors concluded that the study supports the safety and feasibility of extrapleural pneumonectomy with macroscopic complete resection followed by additional therapy. They stated that combined N1 and N2 node involvement has a worse prognosis than either alone, that both stations should be thoroughly staged, and that this finding has implications for revising mesothelioma staging criteria.
• Limitations the authors state:
  • The study has the biases common to all retrospective, single-institution reviews.
  • Patients were treated with multimodal strategies and regimens that changed over the 24-year period.
  • Patients completed their treatment regimens to varying degrees.

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: Extrapleural Pneumonectomy (EPP), Epithelioid, Pleural Mesothelioma, Mesothelioma, Overall Survival, Median Overall Survival, Staging.

Related studies

• Extrapleural pneumonectomy for malignant pleural mesothelioma: outcomes of treatment and prognostic factors — T.D. Yan, M. Boyer, et al. (2009)
• Clinical and pathological features of three-year survivors of malignant pleural mesothelioma following extrapleural pneumonectomy — D.J. Sugarbaker, A.S. Wolf, et al. (2011)
• Low calretinin expression and high neutrophil-to-lymphocyte ratio are poor prognostic factors in patients with malignant mesothelioma undergoing extrapleural pneumonectomy — S.C. Kao, S. Klebe, et al. (2011)
• Summary of prognostic factors and patient selection for extrapleural pneumonectomy in the treatment of malignant pleural mesothelioma — C. Cao, T.D. Yan, et al. (2011)
• Epithelial malignant pleural mesothelioma after extrapleural pneumonectomy: stratification of survival with CT-derived tumor volume — R.R. Gill, W.G. Richards, et al. (2012)
• Intensity-modulated radiotherapy after extrapleural pneumonectomy in the combined-modality treatment of malignant pleural mesothelioma — A. Chi, Z. Liao, et al. (2011)

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