Diffuse mesothelioma of the peritoneum: correlation between histological and clinical parameters and survival in 73 patients

Our plain-English summary of Diffuse mesothelioma of the peritoneum: correlation between histological and clinical parameters and survival in 73 patients, by S. Liu, P. Staats, M. Lee, et al (Pathology, 2014).

The study

• Authors: S. Liu, P. Staats, M. Lee, H.R. Alexander, A.P. Burke
• Journal: Pathology
• Published: 2014;46(7):604-9
• Cited by: 52 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

There are few studies addressing survival of diffuse peritoneal mesotheliomas (DPM).In this study, survival data were obtained retrospectively from 73 patients treated with intended cytoreductive surgery for DPM, with a mean follow-up of 42 months. Mesotheliomas were classified as well differentiated papillary (WDPM, n = 2), multicystic (MCM, n = 4), and epithelioid mesotheliomas were subclassified as tubulopapillary (TPM, n = 27), solid/deciduoid (S/DM, n = 34), and or biphasic mesothelioma (BPM, n = 6). Invasion was characterised as absent (grade 0), into stroma (grade 1), into fat (grade 2), and into adjacent structures (grade 3). Peritoneal cancer index (PCI) and completeness of cytoreduction (CCR) were assessed surgically.There were no deaths in the WDPM, MCM, and epithelioid DPM with ≤ grade 1 invasion. There was a stepwise decrease in overall survival from invasive TPM, S/DM, and BPM (p < 0.0001). By univariate analysis, advanced age (p = 0.01), incomplete CCR (p < 0.001), PCI (p = 0.004), mitotic count (p < 0.001), nuclear grade (p < 0.0001), stromal inflammation (p = 0.013), depth of invasion (p < 0.0001), necrosis (p = 0.002), and sarcomatoid growth (p < 0.0001) were associated with decreased overall survival. By multivariate analysis, only sarcomatoid growth (p = 0.0006), depth of invasion (p = 0.02), elevated CCR (CCR 2-3) (p = 0.02), and presence of inflammatory stroma (p = 0.04) were significant variables associated with decreased overall survival.DPM form a spectrum of indolent to highly aggressive tumours. Solid epithelioid/deciduoid tumours have a prognosis intermediate between biphasic mesotheliomas and invasive TPM. The presence and degree of invasion, sarcomatoid features, and inflammatory stroma are poor prognostic indicators.

In plain English

This retrospective review covered 73 patients with diffuse peritoneal mesothelioma, abdominal-lining tumours the authors described as ranging from indolent to highly aggressive. All were treated with planned cytoreductive surgery and heated intraperitoneal chemotherapy (HIPEC) at the University of Maryland Greenebaum Cancer Center between 2006 and 2013. The authors related tumour features and surgical findings to survival. Mean follow-up was 42.0 months, and 30 patients had died. There were no deaths among the 2 well differentiated papillary tumours, the 4 multicystic tumours, or the epithelioid tumours that did not invade or invaded only the stroma. Median overall survival was not reached for tubulopapillary tumours. It was 47.2 months for solid/deciduoid tumours and 10.6 months for biphasic tumours. In multivariate analysis, four factors were significantly associated with decreased overall survival: sarcomatoid growth, deeper invasion, incomplete cytoreduction (CCR 2 to 3) and inflammatory stroma. The authors concluded that minimally invasive epithelioid tumours behaved similarly to low grade tumours in the short and medium term. They called the link with inflammatory stroma unexpected and said it warrants further study. They noted that more indolent tumour types were under-represented. The article does not discuss asbestos 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 review of a single institution's patient series (survival analysis with univariate and multivariate analysis)
• Who was studied: 73 patients with diffuse peritoneal mesothelioma treated with planned cytoreductive surgery and HIPEC at the University of Maryland Greenebaum Cancer Center, 2006 to 2013. Mean age was 52.5 years (range 15 to 80). There were 36 males and 37 females. Patients with prior pleural mesothelioma or localised tumour were excluded. The tumours ranged from low grade (well differentiated papillary, multicystic) to highly aggressive types.
• Exposure: Not addressed. The article does not report asbestos or any other exposure. It studies tumour histology, invasion and surgical factors in relation to survival.
• Main results:
  • Of the 73 tumours: 2 well differentiated papillary (3%), 4 multicystic (5%), 27 tubulopapillary (37%), 34 solid/deciduoid (47%) and 6 biphasic (8%).
  • At last follow-up, 43 patients were alive and 30 had died. Mean follow-up was 42.0 months.
  • No deaths occurred among well differentiated papillary and multicystic tumours, or among non-invasive or stroma-only epithelioid tumours.
  • Median overall survival by type was not reached for tubulopapillary, 47.2 months for solid/deciduoid, and 10.6 months for biphasic mesothelioma.
  • In univariate analysis, 9 of 11 variables were significantly associated with overall survival: age, completeness of cytoreduction, peritoneal cancer index, mitoses, nuclear grade, stromal inflammation, depth of invasion, necrosis and histology. Patients with CCR 2 to 3 (n = 13) had a median survival of 13.9 months, compared with 118.6 months for CCR 0 to 1 (n = 60).
  • In epithelioid mesotheliomas, fat involvement showed a trend toward poorer survival compared with surface involvement (68.3 months, p = 0.0543). Involvement of adjacent structures showed the worst survival.
  • In multivariate analysis, four factors were significant variables associated with decreased overall survival: sarcomatoid growth, depth of invasion, elevated CCR (CCR 2 to 3) and presence of inflammatory stroma. Invasion and sarcomatoid growth were the only independent histological variables.
  • Mitotic count, nuclear grade, peritoneal cancer index, necrosis and age were significant in univariate analysis. They were not significant in multivariate analysis once degree of invasion was included.
• The authors' conclusion: The authors concluded that minimally invasive classic epithelioid mesotheliomas behaved similarly to low grade tumours (well differentiated papillary and multicystic) in the short and medium term. They described epithelioid mesotheliomas as a heterogeneous group with distinct prognostic profiles. They said the finding on inflammatory stroma was unexpected and warrants further study.
• Limitations the authors state:
  • Only tumours treated with debulking and HIPEC were included, so more indolent, often localised tumour types (well differentiated papillary and multicystic) were under-represented.
  • Only six low grade mesothelial tumours were represented.

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: Mesothelioma, Peritoneum, Peritoneal Mesothelioma, Cytoreductive Surgery, Epithelioid, Tubulopapillary, Biphasic Mesothelioma, Peritoneal Cancer Index (PCI).

Related studies

• Diffuse mesothelioma of the peritoneum: a pathological study of 64 tumours treated with cytoreductive therapy — M. Lee, H.R. Alexander, et al. (2013)
• 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)
• Is PAX2 a reliable marker in differentiating diffuse malignant mesotheliomas of peritoneum from serous carcinomas of müllerian origin? — F.F. Gao, A.M. Krasinskas, et al. (2012)
• Malignant peritoneal mesothelioma: prognostic significance of clinical and pathologic parameters and validation of a nuclear-grading system in a multi-institutional series of 225 cases — D.B. Chapel, J.J. Schulte, et al. (2021)
• Clinical picture, response to therapy, and survival of women with diffuse malignant peritoneal mesothelioma — G.H. Eltabbakh, M.S. Piver, et al. (1999)
• Aberrant Pax-8 expression in well-differentiated papillary mesothelioma and malignant mesothelioma of the peritoneum: a clinicopathologic study — D. Xing, N. Banet, et al. (2018)

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