Characteristics and long-term outcomes of advanced pleural mesothelioma in Latin America (MeSO-CLICaP)

Our plain-English summary of Characteristics and long-term outcomes of advanced pleural mesothelioma in Latin America (MeSO-CLICaP), by L. Rojas, A.F. Cardona, R. Trejo-Rosales, et al (Thoracic Cancer, 2019).

The study

• Authors: L. Rojas, A.F. Cardona, R. Trejo-Rosales, Z.L. Zatarain-Barrón, L.A. Ramírez-Tirado, A. Ruiz-Patiño, S. Campos Gómez, L. Corrales, G. Oblitas, L. Bacon, C. Martín, V.C.C. de Lima, H.C. Freitas, L. Mas, C. Vargas, H. Carranza, J. Otero, M.A. Pérez, L. González, L. Chirinos, S.T. Granados, J. Rodriguez, R. Báez, Y.A. Remolina Bonilla, G. Núñez Cerrillo, P. Archila, M. Cuello, N. Karachaliou, R. Rosell, O. Arrieta, on behalf CLICaP
• Journal: Thoracic Cancer
• Published: 2019;10(3):508-518
• Cited by: 12 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Malignant pleural mesothelioma (MPM) is an aggressive tumor, associated with poor prognosis. There is a lack of information about the clinical and pathological features related with survival in the Latin American population.

Methods: The MeSO-CLICaP registry identified 302 patients with advanced MPM diagnosed and treated between January 2008 and March 2016. The Cox model was applied to determine the variables associated with survival. A random forest tree model was built to predict the response to first-line chemotherapy among Latin American patients.

Results: The median age was 61.1 years (SD 10.6 years), 191 (63.2%) were men, 65.9% were ever smokers, and 38.7% had previous exposure to asbestos. A total of 237 (78.5%) had epithelioid tumors, and 188 (62.3%) and 114 (37.7%) cases had stage III or IV MPM, respectively. A total of 49 patients (16.2%) underwent pleurectomy, 57 (18.9%) received radiotherapy, and 279 patients received first-line platinum-based chemotherapy. The overall response rate to first-line chemotherapy was 40.4%, progression-free survival to first-line treatment was 5.7 months (95% CI 4.9-6.5), and 63 (20.8%) patients had pemetrexed maintenance. The median overall survival was 16.8 months (95% CI 13.0-20.5), and multivariate analysis found that stage (P = 0.013), and pleurodesis (P = 0.048), were independent prognostic factors for first-line overall survival. The model to predict response to first-line chemotherapy obtained a 0.98 area under the curve, a sensitivity of 93%, and a specificity of 95% for detecting responders and non-responders.

Conclusion: This study identifies factors associated with clinical benefit from chemotherapy among advanced MPM Latin American patients, emphasizing the impact of histology and the clinical benefit of chemotherapy on outcomes.

© 2019 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

In plain English

This retrospective study drew on the MeSO-CLICaP registry of 302 patients with advanced malignant pleural mesothelioma from nine Latin American countries, diagnosed and treated between January 2008 and March 2016. Previous asbestos exposure was recorded for 38.7% of them. Fiber types and jobs were not reported. Of the 302, 279 received first-line platinum-based chemotherapy. The response rate to first-line chemotherapy was 40.4%. With first-line treatment, median progression-free survival was 5.7 months (95% CI 4.9–6.5) and median overall survival was 16.8 months (95% CI 13.0–20.5), or 20.7 months (95% CI 14.8–26.6) for epithelioid tumors. The text names disease stage as the only independent factor for first-line overall survival (HR 1.6, 95% CI 1.1–2.4), but the abstract and a table also list pleurodesis. Among 81 patients given third-line treatment, asbestos exposure was independently associated with longer progression-free survival after that treatment (HR 0.2, 95% CI 0.0–0.7). A prediction model detected responders to first-line chemotherapy with 93% sensitivity and 95% specificity. The authors concluded that the study identifies factors associated with benefit from chemotherapy. They noted limitations in patient selection and the absence of molecular testing.

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 multinational patient registry, with Cox survival models and a random forest prediction model
• Who was studied: 302 patients with advanced malignant pleural mesothelioma (stage III or IV) from nine Latin American countries (Argentina, Brazil, Colombia, Costa Rica, Panamá, México, Perú, Nicaragua, Venezuela), diagnosed and treated between January 2008 and March 2016. Of these, 191 (63.2%) were men; age was 61.1 years (SD 10.6).
• Exposure: Previous asbestos exposure was recorded as present in 117 of 302 patients (38.7%), absent in 141 (46.7%) and not available in 44 (14.6%). No fiber types, products or jobs were reported. The treatments studied were pleurectomy, pleurodesis, radiotherapy and chemotherapy. First-line platinum-based chemotherapy was given to 279 patients, with pemetrexed in 148 (53%) and gemcitabine in 129 (46.2%).
• Main results:
  • Overall response rate to first-line chemotherapy: 40.4%
  • Median progression-free survival with first-line therapy: 5.7 months (95% CI 4.9–6.5)
  • Median overall survival after first-line therapy, all patients: 16.8 months (95% CI 13.0–20.5)
  • Median overall survival by tumor type: 20.7 months (95% CI 14.8–26.6) for epithelioid tumors, 13.4 months for sarcomatoid and 14.7 months for mixed histology (univariate P = 0.007)
  • In multivariate analysis, the text reports disease stage as the only independent prognostic factor for overall survival after first-line treatment (HR 1.6, 95% CI 1.1–2.4, P = 0.013)
  • The abstract and Table 4 also list pleurodesis as an independent factor for overall survival (HR 1.4, 95% CI 1.0–2.1, P = 0.048)
  • Overall survival after first-line therapy did not differ significantly by asbestos exposure: median 20.0 months with exposure versus 16.8 months without (P = 0.285)
  • 81 patients (26.8%) received third-line therapy. In this group, asbestos exposure was independently associated with progression-free survival after third-line therapy (HR 0.2, 95% CI 0.0–0.7, P = 0.011). The median was not reached in exposed patients, compared with 4.3 months in unexposed patients.
  • 126 of 302 patients (41.7%) received treatment after first-line therapy. Median overall survival with second-line therapy was 14.6 months (95% CI 11.4–17.8).
  • The prediction model, tested on a 30% validation subset, detected responders and non-responders to first-line chemotherapy with 93% sensitivity and 95% specificity (area under the curve 0.98)
• The authors' conclusion: The authors concluded that the study identifies factors associated with clinical benefit from chemotherapy among Latin American patients with advanced malignant pleural mesothelioma, emphasizing the impact of histology and of chemotherapy benefit on outcomes. They added that second-line chemotherapy appears active, particularly in younger patients with good performance status and prolonged disease control on first-line chemotherapy.
• Limitations the authors state:
  • Limitations in the selection of patients, and no molecular or biomarker analyses were performed
  • Survival was better than in other studies, which the authors say is probably due to selection bias, since nearly all patients received first-line chemotherapy
  • Patients were not in a prospective protocol, so imaging frequency varied
  • The prediction model still has to be validated in other populations

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Prognosis, Chemotherapy, Epithelioid, Progression-Free Survival, Pemetrexed (Alimta), Median Overall Survival, Multivariate Analysis.

Related studies

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• Molecular resistance fingerprint of pemetrexed and platinum in a long-term survivor of mesothelioma — O.D. Røe, A. Szulkin, et al. (2012)
• The clinicopathological characteristics with long-term outcomes in malignant mesothelioma — M. Dogan, G. Utkan, et al. (2014)
• Treatment and Outcomes of Primary Pericardial Mesothelioma: A Contemporary Review of 103 Published Cases — E. McGehee, D.E. Gerber, et al. (2019)
• Children's health in Latin America: the influence of environmental exposures — A. Laborde, F. Tomasina, et al. (2015)
• Prevention of Asbestos Exposure in Latin America within a Global Public Health Perspective — E. Algranti, J.P. Ramos-Bonilla, et al. (2019)

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