Disparities in Compliance With National Guidelines for the Treatment of Malignant Pleural Mesothelioma

Our plain-English summary of Disparities in Compliance With National Guidelines for the Treatment of Malignant Pleural Mesothelioma, by F. Espinoza-Mercado, J.D. Borgella, D. Berz, et al (The Annals of Thoracic Surgery, 2019).

The study

• Authors: F. Espinoza-Mercado, J.D. Borgella, D. Berz, R.F. Alban, A. Sarkissian, H.T.A. Imai, H.J. Soukiasian
• Journal: The Annals of Thoracic Surgery
• Published: 2019;108(3):889-896
• Cited by: 11 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Current guidelines support cancer-directed surgery, chemotherapy, or active surveillance for clinical stages 1 to 3 of epithelial malignant pleural mesothelioma (MPM). Definitive chemotherapy is recommended for sarcomatoid/biphasic histologies. Our objective is to assess compliance with recommendations, measuring their impact on overall survival.

Methods: The National Cancer Database participant user file (2004 to 2014) was queried for patients diagnosed with MPM clinical stages 1 to 3. Multivariable logistic regression model identified factors independently associated with guideline compliance. Kaplan-Meier analysis and Cox proportional hazards were used for overall survival comparison with histologic subgroup analysis.

Results: A total of 3419 patients with clinical stages 1 to 3 met criteria for analysis and comprised epithelial (68.5%), sarcomatoid (17.2%), and biphasic subtypes (14.3%). Cancer-directed surgery was significantly underutilized in epithelial MPM, with 29.3% having no treatment. On multivariable analysis, insurance status and facility type were the strongest predictors of guideline compliance. High-volume hospitals were the most compliant with guidelines (odds ratio 3.58, 95% confidence interval (CI), 2.34 to 5.49, P < .001). Median survival estimates for no treatment, chemotherapy alone, surgery plus chemotherapy, and trimodal therapy were 10.2, 15.4, 21.1, and 21.7 months, respectively (log rank P < .001). In epithelial MPM, a significant increase in overall survival was observed in surgery plus chemotherapy (hazard ratio 0.62, 95% CI, 0.53 to 0.73, P < .001) and trimodality (hazard ratio 0.61, 95% CI, 0.49 to 0.76, P < .001; reference: no treatment).

Conclusions: There is a suboptimal compliance with national guidelines for the treatment of MPM, particularly in low-volume nonacademic settings. Adherence to recommended surgery-based multimodal therapy is associated with an overall survival improvement.

Copyright © 2019 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

In plain English

This retrospective study used US National Cancer Database records of adults diagnosed 2004 to 2014 with clinical stage 1 to 3 malignant pleural mesothelioma. It did not examine asbestos exposure. It assessed guideline compliance and survival by treatment. Of 3419 patients, 2339 had epithelial, 589 sarcomatoid and 491 biphasic tumors. Among epithelial patients, 29.3% received no treatment and 27.1% had cancer-directed surgery. Guideline-compliant care for epithelial disease was less likely at age 80 or older and for women. It was more likely for privately insured and Medicare patients than for uninsured patients, at academic centers, and at high-volume rather than low-volume hospitals (odds ratio 3.58, 95% CI 2.34 to 5.49). Median epithelial survival was 10.2 months (95% CI 8.9 to 11.5) with no treatment, 15.4 (14.3 to 16.4) with chemotherapy alone, 21.1 (19.1 to 23) with surgery plus chemotherapy and 21.7 (17.6 to 25.7) with trimodal therapy. The authors concluded that compliance was suboptimal, especially in low-volume nonacademic settings, and that surgery-based multimodal therapy was associated with longer survival. They noted selection bias and missing performance status data.

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 a national cancer registry database (National Cancer Database), using logistic regression for factors linked to guideline compliance and Kaplan-Meier and Cox models for survival
• Who was studied: 3419 adults (18 or older) in the US National Cancer Database diagnosed 2004 to 2014 with clinical stage 1 to 3 malignant pleural mesothelioma. Of these, 2339 had epithelial, 589 sarcomatoid and 491 biphasic histology. Patients came from 854 institutions. Patients with metastatic disease, unknown stage or histology not otherwise specified were excluded.
• Exposure: Not asbestos. The study compared treatments received (no treatment, surgery, chemotherapy, radiotherapy, combinations, active surveillance), classed as guideline-compliant or not by histologic subtype. It also looked at patient and hospital factors such as age, sex, insurance and hospital volume.
• Main results:
  • Among epithelial patients, 29.3% received no treatment, and only 27.1% received some form of cancer-directed surgery.
  • In epithelial patients, people aged 80 or older were the group at highest risk of low guideline compliance compared with younger patients (odds ratio 0.07, 95% CI 0.03 to 0.16).
  • In epithelial patients, women had higher odds of not being treated than men (OR 0.79, 95% CI 0.64 to 0.96).
  • In epithelial patients, those with private insurance had higher odds of being treated than uninsured patients (OR 1.93, 95% CI 1.03 to 3.62).
  • In epithelial patients, those with Medicare had higher odds of being treated than uninsured patients (OR 2.05, 95% CI 1.08 to 3.86).
  • In epithelial patients, high-volume hospitals had the best guideline compliance compared with low-volume centers (OR 3.58, 95% CI 2.34 to 5.49).
  • In epithelial patients, academic centers were more likely to follow guidelines than nonacademic facilities (OR 1.57, 95% CI 1.30 to 1.90).
  • In epithelial patients, socioeconomic status was not associated with treatment compliance.
  • For sarcomatoid and biphasic histologies, age and insurance differences were not statistically significant. Only clinical stage and academic facility type were significantly associated with guideline compliance.
  • Median survival in epithelial patients by treatment group: no treatment 10.2 months (95% CI 8.9 to 11.5); chemotherapy alone 15.4 months (95% CI 14.3 to 16.4); surgery plus chemotherapy 21.1 months (95% CI 19.1 to 23); trimodal therapy 21.7 months (95% CI 17.6 to 25.7).
  • In epithelial patients, compared with no treatment, overall survival was significantly better with surgery plus chemotherapy (hazard ratio 0.62, 95% CI 0.53 to 0.73) and with trimodality therapy (hazard ratio 0.61, 95% CI 0.49 to 0.76).
  • A sensitivity analysis excluded patients with early operative mortality and those not completing multimodal therapy. In it, the survival benefit for cancer-directed surgical groups remained compared with no treatment and chemotherapy alone.
• The authors' conclusion: The authors concluded that compliance with national guidelines for treating malignant pleural mesothelioma was suboptimal, particularly in low-volume nonacademic settings. They also concluded that adherence to recommended surgery-based multimodal therapy was associated with improved overall survival.
• Limitations the authors state:
  • The retrospective design carries inherent selection bias.
  • The database has no performance status data. The authors used the Charlson comorbidity score instead, which they said cannot substitute for it.
  • Surgery codes in the database could not distinguish pleurectomy/decortication from extrapleural pneumonectomy, so only curative-intent or radical surgery could be reported.
  • Expert centers do not strictly follow the NCCN treatment algorithm. For example, some offer surgery for mixed-type tumors.

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, Chemotherapy, Active Surveillance, Sarcomatoid, Biphasic Mesothelioma, Overall Survival, Odds Ratio, confidence interval.

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