Malignant Peritoneal Mesothelioma: National Practice Patterns, Outcomes, and Predictors of Survival

Our plain-English summary of Malignant Peritoneal Mesothelioma: National Practice Patterns, Outcomes, and Predictors of Survival, by V. Verma, R.L. Sleightholm, C.G. Rusthoven, et al (Annals of Surgical Oncology, 2018).

The study

• Authors: V. Verma, R.L. Sleightholm, C.G. Rusthoven, M. Koshy, D.J. Sher, S. Grover, C.B. Simone
• Journal: Annals of Surgical Oncology
• Published: 2018;25(7):2018-2026
• Cited by: 59 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Purpose: This study of a large, contemporary national database evaluated management patterns, outcomes, and prognostic factors of malignant peritoneal mesothelioma (MPM) in the USA.

Methods: The National Cancer Data Base was queried for newly diagnosed nonmetastatic MPM. Patients were divided into five cohorts: observation, chemotherapy alone, cytoreductive surgery (CRS) alone, CRS/chemo [referring to any non-hyperthermic intraperitoneal chemotherapy (HIPEC) chemotherapy], and CRS/HIPEC. Statistics included multivariable logistic regression, Kaplan-Meier analysis, and Cox proportional hazards modeling.

Results: Of 1514 patients, 379 (25%) underwent observation, 370 (24%) received chemotherapy only, 197 (13%) CRS alone, 352 (23%) CRS/chemo, and 216 (14%) CRS/HIPEC. No major temporal trends in management were noted. Factors predictive of CRS administration included younger age, female gender, insurance status, residence in educated areas, living farther from treating institutions, and treatment at academic centers (p < 0.05 for all). Compared with epithelioid histology, those with sarcomatoid and biphasic histology were less and more likely to undergo CRS, respectively (p < 0.05 for both). In all CRS patients, 30- and 90-day mortality rates were 0.8 and 1.2%, respectively. At median follow-up of 50 months, median OS in the respective groups was 6, 17, 21, 52, and 61 months (p < 0.001). Poor prognostic factors included advanced age, male gender, uninsured/Medicaid insurance, and sarcomatoid/biphasic histology (p < 0.05 for all).

Conclusions: In the USA, MPM is treated using a wide variety of strategies. Many factors impact the type of treatment delivered, including age, sociodemographics, geography, histology, and facility type. Although these data do not imply causation, combined-modality management seems associated with the longest OS.

In plain English

This retrospective study used the US National Cancer Data Base to examine treatment and survival in malignant peritoneal mesothelioma from 2004 to 2013. It included 1514 patients with newly diagnosed disease that had not spread to distant sites. Of these, 379 (25%) had neither chemotherapy nor surgery, 370 (24%) had chemotherapy only, 197 (13%) had cytoreductive surgery (CRS) alone, 352 (23%) had CRS with other chemotherapy, and 216 (14%) had CRS with hyperthermic intraperitoneal chemotherapy (HIPEC), which the authors defined as chemotherapy starting the same day as surgery. Median overall survival was 61 months (95% confidence interval 45–70) with CRS/HIPEC, 52 (44–60) with CRS plus other chemotherapy, 21 (13–26) with CRS alone, 17 (14–24) with chemotherapy alone and 6 (5–8) with observation. Older age, male gender, being uninsured or having Medicaid insurance, and sarcomatoid or biphasic tumor types were linked to shorter survival. The authors concluded that combined treatment seemed associated with the longest survival. They stated that the data do not imply causation and that surgery patients were likely well selected. The database largely did not record occupational exposure.

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 Data Base)
• Who was studied: 1514 patients in the USA with newly diagnosed, histologically confirmed nonmetastatic malignant peritoneal mesothelioma, drawn from the National Cancer Data Base mesothelioma file for 2004–2013
• Exposure: The study compared treatments: observation, chemotherapy alone, cytoreductive surgery (CRS) alone, CRS with non-HIPEC chemotherapy, and CRS with HIPEC. CRS/HIPEC was defined as surgery and chemotherapy recorded on the same day. Asbestos or other occupational exposure was largely not recorded in the database and was not analyzed.
• Main results:
  • Treatment received, out of 1514 patients: 379 (25%) observation, 370 (24%) chemotherapy only, 197 (13%) CRS alone, 352 (23%) CRS/chemo, 216 (14%) CRS/HIPEC
  • Median overall survival was similar in the CRS/HIPEC group, 61 months (95% CI 45–70), and the CRS/chemo group, 52 months (95% CI 44–60) (p = 0.844)
  • Median overall survival was 21 months (13–26) for CRS only and 17 months (14–24) for chemotherapy alone, which did not differ from each other (p = 0.476). It was lowest in the observation group at 6 months (5–8).
  • Five-year overall survival was 52% (41–58%) for CRS/HIPEC, 43% (36–49%) for CRS/chemo, 22% (13–32%) for CRS only, 22% (17–31%) for chemotherapy alone and 9% (6–13%) for observation
  • In the multivariate analysis, advanced age, male gender, uninsured or Medicaid insurance, and sarcomatoid or biphasic histology were independently associated with poorer overall survival. Compared with epithelioid histology, the hazard ratio was 1.750 (1.250–2.449) for sarcomatoid and 1.508 (1.070–2.124) for biphasic.
  • Compared with CRS/HIPEC, CRS alone, chemotherapy only and observation were each associated with poorer survival. CRS/chemo had similar survival to CRS/HIPEC (p = 0.397).
  • CRS was more often given to younger, female and insured patients. Females, however, were less likely to receive CRS/HIPEC specifically (p = 0.006).
  • Among all patients who had CRS, the 30-day readmission rate was 6.1%, and the 30-day and 90-day mortality rates were 0.8% and 1.2%
• The authors' conclusion: The authors concluded that malignant peritoneal mesothelioma is treated in many different ways in the USA, and that treatment choice depends on factors including age, sociodemographics, geography, histology and facility type. Combined-modality management seemed associated with the longest survival, although the data do not imply causation.
• Limitations the authors state:
  • The study was retrospective, so the authors said the survival findings must be interpreted conservatively
  • Patients receiving CRS were likely well selected
  • The CRS/chemo group mixed different types of chemotherapy, because the database does not record the route or duration of chemotherapy
  • HIPEC was defined as chemotherapy starting on the same day as surgery, which could misclassify some patients
  • Findings may not represent the whole US population, because only accredited facilities contribute data
  • Missing data on histology, tumor bulk and extent of cytoreduction made interpretation difficult
  • The database does not track variables such as surgeon experience or salvage and intraoperative therapies, which could confound the results
  • Occupational exposure was largely not recorded in the database

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma, Peritoneal mesothelioma.

Medical terms in this study, explained in our Lexicon: Peritoneal Mesothelioma, Chemotherapy, Cytoreductive Surgery, HIPEC, Epithelioid, Histology, Sarcomatoid, Biphasic Mesothelioma.

Related studies

• Iterative cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for recurrent or progressive diffuse malignant peritoneal mesothelioma: clinicopathologic characteristics and survival outcome — C. Ihemelandu, L. Bijelic, et al. (2015)
• Long-term Survival and Propensity Score Matched Outcomes of Bilateral vs. Unilateral Diaphragm Interventions in Cytoreductive Surgery plus Intra-peritoneal Chemotherapy — B. Singh, G. Singh, et al. (2018)
• Preoperative Thrombocytosis Predicts Shortened Survival in Patients with Malignant Peritoneal Mesothelioma Undergoing Operative Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy — Y.C. Li, T. Khashab, et al. (2017)
• The Role of Ki-67 and Pre-cytoreduction Parameters in Selecting Diffuse Malignant Peritoneal Mesothelioma (DMPM) Patients for Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) — S. Kusamura, P.A. Torres Mesa, et al. (2016)
• A Novel Tool for Predicting Major Complications After Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy — J.M. Baumgartner, T.G. Kwong, et al. (2016)
• Laparoscopy is Safe and Accurate to Evaluate Peritoneal Surface Metastasis Prior to Cytoreductive Surgery — R.A. Marmor, K.J. Kelly, et al. (2016)

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