Current trends in the management of malignant peritoneal mesothelioma

Our plain-English summary of Current trends in the management of malignant peritoneal mesothelioma, by J.T. Miura, F.M. Johnston, T.C. Gamblin, et al (Annals of Surgical Oncology, 2014).

The study

• Authors: J.T. Miura, F.M. Johnston, T.C. Gamblin, K.K. Turaga
• Journal: Annals of Surgical Oncology
• Published: 2014;21(12):3947-53
• Cited by: 37 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Historically, malignant peritoneal mesothelioma (MPM) has been considered an aggressive and lethal neoplasm. However, contemporary series have demonstrated improved outcomes following a combination of cytoreductive surgery and intraperitoneal chemotherapy. We sought to assess the trends in management and survival of patients with MPM in the United States.

Methods: The Surveillance, Epidemiology, and End Results database was used to identify all patients diagnosed with malignant peritoneal mesothelioma from 1973 to 2010. Overall survival (OS) was studied with Kaplan-Meier curves and Cox regression analyses.

Results: We identified 1,591 patients with MPM. Median age at diagnosis was 64 years (IQR 53-74 years) with the majority of patients presenting with metastatic disease (n = 962, 60.5 %). A total of 980 patients (61.6 %) did not receive surgical therapy. Receipt of radical cytoreduction for patients with metastatic MPM demonstrated a significant improvement in OS compared with patients not receiving surgery (20 vs. 4 months, p < 0.01). A temporal increase was observed in OS for patients receiving surgery (1991-1995: 15 vs. 2006-2010: 38 months, p = 0.1). In multivariate models, limited (HR 0.55; 95 % CI 0.48-0.63; p < 0.01) and radical (HR 0.66; 95 % CI 0.54-0.80; p < 0.01) surgery were independently associated with improved survival.

Conclusions: In the current era, approximately three of every five patients do not receive surgery when diagnosed with MPM, although a significant survival benefit is noted in select patients. The opportunity to improve patient survival with surgical therapy is lost in a significant number of MPM patients.

In plain English

This study used the U.S. SEER cancer registry to examine treatment and survival in malignant peritoneal mesothelioma (cancer of the abdominal lining) diagnosed from 1973 to 2010. The authors called it a retrospective case series analysis of 1,591 patients. It studied surgery, not asbestos exposure. 980 patients (61.6%) had no surgery. Median survival overall was 9 months. Among patients with metastatic disease, median survival, measured from diagnosis, was 20 months for radical surgery, 13 months for limited surgery and 4 months for no surgery. In multivariate analysis, limited surgery (hazard ratio 0.55; 95% CI 0.48 to 0.63) and radical surgery (hazard ratio 0.66; 95% CI 0.54 to 0.80) were independently associated with longer survival. Among surgical patients, median survival rose from 15 months (1991 to 1995) to 38 months (2006 to 2010); the log-rank p value was 0.1 and the trend p value 0.01. The authors noted that SEER does not record performance status or delivery of systemic chemotherapy. They concluded that about three of every five patients do not receive surgery, although a significant survival benefit is noted in select patients.

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 case series analysis of a population-based U.S. cancer registry (SEER), using Kaplan-Meier survival curves and Cox regression
• Who was studied: 1,591 patients with malignant peritoneal mesothelioma recorded in the U.S. SEER registry from 1973 to 2010. Median age was 64 years and 688 (43.2%) were female. Patients with mesothelioma originating from the pleura or genital tracts were excluded.
• Exposure: The factor studied was treatment, specifically the extent of surgery (no surgery, surgery not otherwise specified, limited resection, radical resection), along with year of diagnosis. Asbestos exposure was not studied; it is mentioned only in the introduction, citing other work.
• Main results:
  • Of the 1,591 patients, 980 (61.6%) did not undergo surgery. 611 (38.4%) had surgery: radical 284 (17.9%), limited 188 (11.8%), and surgery type missing 139 (8.7%).
  • Median overall survival, calculated from the time of diagnosis, was 9 months (IQR 2 to 36 months) for the entire cohort. It was 21 months for patients with local/regional disease and 7 months for patients with metastatic disease (p less than 0.01).
  • In patients with metastatic disease, median overall survival was 20 months among those receiving radical surgery, 13 months among those receiving limited surgery and 4 months among those receiving no surgery (p less than 0.01).
  • In patients with local/regional disease, median overall survival was 48, 27 and 13 months, with 13 months for patients who had no surgery (p less than 0.01). The text does not clearly state which surgery type corresponds to 48 and which to 27 months.
  • In multivariate analysis of all 1,591 patients, limited surgery (HR 0.55; 95% CI 0.48 to 0.63) and radical surgery (HR 0.66; 95% CI 0.54 to 0.80) were independently associated with improved overall survival compared with no surgery. Female gender was also associated with improved survival (HR 0.75; 95% CI 0.66 to 0.84).
  • Increasing age, biphasic histology (HR 1.73; 95% CI 1.25 to 2.39, compared with epithelioid) and advanced tumor stage were independent poor prognostic indicators for survival.
  • The share of patients managed without surgery fell from 66.7% (before 1991) to 56.8% (2006 to 2010). Patients diagnosed in 2006 to 2010 had the highest frequency of surgical resection in the last two decades (41.3%).
  • Among patients who had surgery, median overall survival was 15 months for those diagnosed in 1991 to 1995, 19 months in 1996 to 2000, 24 months in 2001 to 2005 and 38 months in 2006 to 2010. The log-rank p value was 0.1 and the trend p value was 0.01.
  • Among patients who did not have surgery, median overall survival rose from 4 months (1991 to 1995) to 7 months (2006 to 2010). This trend was not statistically significant (log-rank p = 0.37; trend p = 0.64).
  • 1,125 patients (70.7%) lacked a complete histopathologic assessment. Among those with one, epithelioid histology (415, 26.1%) was most common, followed by biphasic (51, 3.2%). No sarcomatoid subtypes were identified.
• The authors' conclusion: The authors concluded that about three of every five patients diagnosed with malignant peritoneal mesothelioma do not receive surgery, although a significant survival benefit is noted in select patients. In their view, the opportunity to improve survival with surgery is lost in a significant number of patients.
• Limitations the authors state:
  • The SEER registry does not capture important clinical and pathological variables: patient performance status, tumor margin status, specific details of the surgical procedure, and delivery of systemic chemotherapy. The authors say this may limit the generalizability of the results.
  • Data were incomplete: 259 patients (16.3%) lacked complete SEER staging, and 1,125 (70.7%) lacked complete histologic analysis.
  • The authors suggest that the number of patients recorded as not receiving surgery could partly reflect patients migrating between registries without their data being captured, or data collection bias.

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, Neoplasm, Cytoreductive Surgery, Chemotherapy, Epidemiology, Overall Survival, Kaplan-Meier Curve.

Related studies

• Efficacy of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy in the management of malignant ascites — R.W. Randle, K.R. Swett, et al. (2014)
• Malignant Peritoneal Mesothelioma: National Practice Patterns, Outcomes, and Predictors of Survival — V. Verma, R.L. Sleightholm, et al. (2018)
• Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for malignant peritoneal mesothelioma: a systematic review and meta-analysis — J.H. Helm, J.T. Miura, et al. (2015)
• Current management strategies for peritoneal mesothelioma — K.K. Turaga, M. Deraco, 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)

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