Analysis of Treatment Strategies and Outcomes in Malignant Peritoneal Mesothelioma: Insights From a Multi-Center Study

Our plain-English summary of Analysis of Treatment Strategies and Outcomes in Malignant Peritoneal Mesothelioma: Insights From a Multi-Center Study, by S. Yaşar, F. Yılmaz, G. Utkan, et al (Annals of Surgical Oncology, 2024).

The study

• Authors: S. Yaşar, F. Yılmaz, G. Utkan, E. Algın, D. Bayram, S. Tamam, Ö.B.Ç. Öksüzoğlu, A. İlhan, E.C. Erdat, A.E. Ünal, Ş. Yalçın
• Journal: Annals of Surgical Oncology
• Published: 2024;31(9):6228-6236
• Cited by: 11 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: This study aimed to evaluate the demographic," clinicopathologic, and prognostic characteristics of malignant peritoneal mesothelioma (MPeM), as well as the treatment options for the rare and heterogeneous MPeM population.

Methods: A retrospective multi-center observational cohort study was conducted to evaluate patients with MPeM. Due to the heterogeneity of the study population, the study divided them into two main groups in terms of treatments, follow-up periods, and prognostic features. The first group comprised the patients who underwent cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), and the second group included the patients with metastatic disease for whom curative intent surgery was not possible. The patients' diagnostic procedures and treatments were identified from medical records. Patients older than 18 years old were included in the study regardless of asbestos exposure. Well-differentiated papillary and multicystic mesothelioma histologic types were not included in the study.

Results: The study evaluated 118 patients from five centers. Survival times, prognosis, and treatment responses were analyzed in both groups. The study showed that CRS-HIPEC was associated with longer overall survival (OS) and progression-free survival (PFS). Perioperative therapy was evaluated in subgroup analyses of this population and shown to provide survival benefits. The patients treated with chemotherapy (metastatic and medically inoperable patients and those for whom complete cytoreduction was not achievable) had a poorer prognosis than the surgery group. The study showed that life expectancy decreased significantly for the patients not suitable to undergo surgery for any reason.

Conclusions: According to data from experienced centers, CRS-HIPEC is a treatment option recognized as effective, cost-effective, and safe, with better OS and PFS , as well as low morbidity and mortality rates similar to those in the literature. In addition, the platinum-pemetrexed combination continues to be an effective and acceptable treatment option for metastatic patients, those who are medically inoperable, and those for whom complete or near-complete cytoreduction is not achievable.

© 2024. The Author(s).

In plain English

This retrospective study covered 118 adults with malignant peritoneal mesothelioma at five centers in Ankara, Turkey; years are not stated. Table 1 lists 61 (51.7%) as asbestos-exposed; exposure was not required for inclusion. Fifty-four patients had cytoreductive surgery with heated abdominal chemotherapy (CRS-HIPEC), 49 had chemotherapy, and 15 had no treatment because of poor health. Median overall survival was 13.8 months for all patients (95% CI 8.7 to 18.9). It was 44.6 months after CRS-HIPEC (95% CI 0 to 102), 12.6 months (9.17 to 16.03) for patients unable to have surgery or complete tumor removal, and 11.2 months (6.014 to 16.38) for those with metastatic disease. Untreated patients survived a median of 1.7 months (1.09 to 2.44). After surgery, the amount of residual tumor was the strongest independent predictor of survival. Asbestos exposure was not significantly related to survival in either group. The authors reported that CRS-HIPEC was associated with longer survival in experienced centers and concluded that platinum-pemetrexed remains acceptable for patients who cannot have curative surgery. They noted the retrospective design and mixed patient group as limitations.

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 multi-center observational cohort study based on medical records
• Who was studied: 118 patients older than 18 with malignant peritoneal mesothelioma from five centers in Ankara, Turkey. Well-differentiated papillary and multicystic types were excluded. There were 66 men and 52 women, with a median age of 62 years. Histology: 84 epithelioid, 11 non-epithelioid, 23 not otherwise specified. The study period is not stated.
• Exposure: The study examined treatments: CRS-HIPEC (54 patients, 31 with adjuvant and 8 with neoadjuvant therapy), chemotherapy for metastatic disease (12) or for medically inoperable or incompletely resectable disease (37), and no treatment (15). Asbestos exposure was recorded only as yes, no or unknown. No fiber types, sources or doses are given.
• Main results:
  • Asbestos exposure in Table 1: yes in 61 patients (51.7%), no in 46 (39%), unknown in 11 (9.3%), out of 118. The text elsewhere states 61%.
  • All 118 patients: median overall survival 13.8 months (95% CI 8.7 to 18.9). One-year overall survival was 54% and two-year overall survival 39%.
  • Median overall survival was 12.6 months for medically inoperable or incompletely resectable patients, 11.2 months for metastatic patients and 44.6 months for CRS-HIPEC patients. The difference was statistically significant (p less than 0.001).
  • CRS-HIPEC group (54 patients): median overall survival 44.6 months (95% CI 0 to 102) and median progression-free survival 7.63 months (95% CI 4.45 to 10.8). Two patients died early from postoperative complications.
  • Non-surgical, non-metastatic group: median overall survival 12.6 months (95% CI 9.17 to 16.03). Metastatic group: median overall survival 11.2 months (95% CI 6.014 to 16.38).
  • Among 46 surgical patients with scores available, one-year survival was 93% with little or no residual tumor (CC 0 to 1) versus 17% with more residual tumor (CC 2 to 3). It was 88% with a lower peritoneal cancer index (0 to 20) versus 32% with a higher index (21 to 39).
  • In the surgical group, multivariate analysis found the completeness of cytoreduction score to be the most important independent prognostic factor (HR 8.839; 95% CI 2.901 to 26.937; p less than 0.001).
  • Surgical patients given perioperative treatment had a median overall survival of 67 months versus 44 months. The difference was not statistically significant (p = 0.596).
  • Asbestos exposure was not significantly associated with survival. In the surgical group the HR was 0.99 (95% CI 0.406 to 2.41; p = 0.982). In the non-surgical group the HR was 0.831 (95% CI 0.429 to 1.612; p = 0.582).
  • In the non-surgical group, multivariate analysis found poor performance status (HR 5.309; 95% CI 2.377 to 11.86) and ascites (HR 5.99; 95% CI 2.386 to 15.037) were independently associated with poor survival.
  • The 15 untreated patients had a median survival of 1.7 months (95% CI 1.09 to 2.44).
• The authors' conclusion: The authors reported that CRS-HIPEC was associated with longer overall and progression-free survival. They concluded that, in experienced centers, it is an effective and safe option. They also concluded that platinum-pemetrexed remains an effective and acceptable option for metastatic, medically inoperable or incompletely resectable patients.
• Limitations the authors state:
  • The study was retrospective, the patient group was heterogeneous, and patient selection differed between surgical centers and other treatment methods.
  • There were too few patients and too short a follow-up to assess perioperative treatments.

Topics

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

Medical terms in this study, explained in our Lexicon: Peritoneal Mesothelioma, Cohort Study, Cytoreductive Surgery, HIPEC, Asbestos Exposure, Well-Differentiated, Multicystic Mesothelioma (MCM), Prognosis.

Related studies

• The role of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in the treatment of peritoneal carcinomatosis: a systematic review including evidence from Japan — T. Kitai (2021)
• Unresectable peritoneal metastasis treated by pressurized intraperitoneal aerosol chemotherapy (PIPAC) leading to cytoreductive surgery and hyperthermic intraperitoneal chemotherapy — M. Alyami, F. Mercier, et al. (2021)
• Malignant Peritoneal Mesothelioma: National Practice Patterns, Outcomes, and Predictors of Survival — V. Verma, R.L. Sleightholm, et al. (2018)
• 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)
• The Safety of Iterative Cytoreductive Surgery and HIPEC for Peritoneal Carcinomatosis: A High Volume Center Prospectively Maintained Database Analysis — E. Bekhor, J. Carr, et al. (2020)
• Laparoscopic cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for limited peritoneal metastasis. The PSOGI international collaborative registry — A. Arjona-Sanchez, O. Aziz, et al. (2021)

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