Concerning CT features predict outcome of treatment in patients with malignant peritoneal mesothelioma

Our plain-English summary of Concerning CT features predict outcome of treatment in patients with malignant peritoneal mesothelioma, by P.H. Sugarbaker, D. Chang, J.S. Jelinek (European Journal of Surgical Oncology, 2021).

The study

• Authors: P.H. Sugarbaker, D. Chang, J.S. Jelinek
• Journal: European Journal of Surgical Oncology
• Published: 2021;47(9):2212-2219
• Cited by: 16 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Malignant peritoneal mesothelioma is an aggressive local-regional disease with dissemination to all parts of the abdomen and pelvis at the time of diagnosis. Recently, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has been used and improved survival was documented with this local-regional treatment strategy.

Method: Concerning CT features were described that were specific for malignant peritoneal mesothelioma. The incidence of concerning radiologic features and their impact on survival was determined. The prognostic assessment of concerning CT features was compared to the peritoneal cancer index (PCI) and the completeness of cytoreduction score (CC score).

Results: One hundred patients with a preoperative CT were evaluated by 11 concerning CT features. The incidence of these CT features varied between 5% and 41%. Nine of the 11 CT features statistically significantly predicted a reduced survival in these patients treated in a uniform manner. When concerning radiologic features were grouped as none, a single feature or two or more features, a significant composite analysis was achieved with p < 0.001. The prognostic information from concerning CT features compared favorably with the prognostic implications of PCI and CC score.

Conclusions: The availability of the concerning CT features to predict prognosis at the initiation of treatments for malignant peritoneal mesothelioma shows that this radiologic assessment may be of great value to the clinician in planning a treatment strategy for an individual patient.

Copyright © 2021 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

In plain English

This study asked whether features on CT scans taken before surgery were linked to survival in malignant peritoneal mesothelioma, a mesothelioma of the abdominal lining. The authors reviewed scans from 100 patients with the epithelial type of the disease. All were treated at one Washington, DC hospital over 22 years with cytoreductive surgery plus heated chemotherapy delivered into the abdomen (HIPEC). A radiologist and a surgeon reread each scan for 11 "concerning" features. Median overall survival for the group was 64 months. Nine of the 11 features were statistically significantly associated with shorter survival. Enlarged cardiophrenic angle lymph nodes and a mass over 5 cm in the peritoneal space but not next to the jejunum were not. Of 16 patients with pleural effusion, 15 died of the disease. Median survival was not reached for the 32 patients with no concerning features. It was 82.4 months for the 14 with one feature and 24.3 months for the 54 with two or more. The authors concluded that these CT features can predict treatment outcome. They noted that the scans lacked coronal and sagittal views. Asbestos exposure was not studied.

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: Single-institution study of patients from a prospective database. Preoperative CT scans were re-reviewed for 11 concerning features, and each feature was compared with overall survival using univariate survival analysis and Kaplan-Meier analysis.
• Who was studied: 100 of 165 patients in the institution's database, treated at MedStar Washington Hospital Center, Washington, DC. All had biopsy-confirmed malignant epithelial peritoneal mesothelioma, a preoperative CT and initial cytoreductive surgery plus HIPEC. Cases were collected over 22 years since 1998, with follow-up to October 1, 2019. There were 57 males; ages ranged from 21 to 74 (median 51). Sarcomatoid, biphasic, cystic and papillary types were excluded.
• Exposure: Asbestos exposure was not studied. The factors examined were 11 preoperative CT features, such as obstructed small bowel, pleural effusion and ascites. The authors note only that asbestos exposure is often difficult to determine.
• Main results:
  • Median overall survival for all 100 patients was 64 months (5.4 years).
  • Nine of the 11 CT features were statistically significantly associated with reduced survival in univariate analysis.
  • Enlarged cardiophrenic angle lymph nodes (23% of patients) were not significantly associated with survival: hazard ratio 1.28 (95% CI 0.71, 2.29), p = 0.4066.
  • A tumor mass greater than 5 cm within the peritoneal space but not adjacent to the jejunum (5% of patients) was not significantly associated with survival: hazard ratio 1.64 (95% CI 0.59, 4.53), p = 0.3391. Table 1 labels this feature "Abdominal mass >5 cm". By contrast, a mass greater than 5 cm adjacent to the jejunum was significant: hazard ratio 2.88 (95% CI 1.58, 5.25), p = 0.0006.
  • Pleural effusion (16% of patients) had a hazard ratio of 3.32 (95% CI 1.86, 5.92), p less than 0.0001. Median survival was 18 months with the feature present versus 82 months without it. Fifteen of the 16 patients with pleural effusion died of malignant peritoneal mesothelioma.
  • All 7 of 7 patients with obstructed small bowel died of disease (hazard ratio 3.93, 95% CI 1.73, 8.95).
  • Of 16 patients with clumped small bowel mesentery, 15 died of the disease (hazard ratio 3.13, 95% CI 1.69, 5.80).
  • Of the 100 patients, 32 had no concerning CT features, 14 had one and 54 had two or more.
  • Median survival was not reached for patients with no concerning features. It was 82.4 months with one feature and 24.3 months with two or more (p less than 0.0001).
  • For comparison, the authors also looked at two scores measured during surgery. A greater extent of disease by peritoneal cancer index was associated with reduced survival (PCI groups 0 to 15, 16 to 30 and over 30; p = 0.0001). Survival also differed by completeness of cytoreduction score (CC-0 and 1 versus 2 versus 3; p less than 0.0001).
• The authors' conclusion: The authors concluded that a greater extent of disease, as assessed by the concerning CT features, can accurately predict the outcome of treatment. They add that this information is available before surgery, unlike PCI and CC score.
• Limitations the authors state:
  • The scans lacked coronal and sagittal imaging planes; only cross-sectional images were used.
  • Because the study covered 22 years, a variety of CT scanners and protocols were used.
  • Disease-free survival was not reported because those data were inaccurate; most follow-up took place at referring institutions.
  • The CT technology was not accurate enough to estimate a CT-based peritoneal cancer index.
  • Most features were scored only as present or absent. The authors suggest that measuring their extent might work better.

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, Cytoreductive Surgery, HIPEC, Peritoneal Cancer Index (PCI), Prognosis.

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• CT differentiation of diffuse malignant peritoneal mesothelioma and peritoneal carcinomatosis — Y.F. Liang, G.Q. Zheng, et al. (2016)
• Radiological characteristics, histological features and clinical outcomes of lung cancer patients with coexistent idiopathic pulmonary fibrosis — K.A. Khan, M.P. Kennedy, et al. (2015)
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• Preoperative computed tomography does not predict resectability in peritoneal carcinomatosis — J.D. Rivard, W.J. Temple, et al. (2014)

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