Treatment and survival analyses of malignant mesothelioma in Japan

Our plain-English summary of Treatment and survival analyses of malignant mesothelioma in Japan, by K. Gemba, N. Fujimoto, K. Aoe, et al (Acta Oncologica, 2013).

The study

• Authors: K. Gemba, N. Fujimoto, K. Aoe, K. Kato, Y. Takeshima, K. Inai, T. Kishimoto
• Journal: Acta Oncologica
• Published: 2013;52(4):803-8
• Cited by: 40 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: There are few reports concerning treatment strategies and their contributions to survival of patients with malignant mesothelioma (MM) in Japan.

Material And Methods: We extracted all death cases due to MM between 2003 and 2008. The diagnosis of MM was confirmed in 929 cases. Histological subtypes was determined in 709 cases, including 396 (55.9%) epithelioid, 154 (21.7%) sarcomatoid, 126 (17.8%) biphasic, and 33 (4.7%) other types.

Results And Conclusion: Median overall survival (OS) of all MM cases was 7.7 months (95% confidence interval, 7.1-8.3). Median OS of patients with epithelioid MM was significantly longer than that of patients with biphasic (p = 0.030) or sarcomatoid (p < 0.001) MM. Surgical resection was performed in 172 patients (18.5%) and 449 (48.3%) received systemic chemotherapy. Survival of patients treated with both surgery and systemic chemotherapy was favorable. Median OS of patients in the late phase of the study period (2006-2008) was significantly longer than that in the early phase (2003-2005) (8.1 vs. 7.5 months, p = 0.008). Independent favorable prognostic factors included age younger than 70 years, female gender, epithelioid subtype, and clinical stage I-III. Multivariate analysis demonstrated that patients who had radical surgery and systemic chemotherapy showed a longer survival, though this could be due to selection bias of patients.

In plain English

This nationwide retrospective survey covered 6030 malignant mesothelioma deaths in Japan in 2003–2008; medical information (records, x-ray films and/or CT images) was obtained for 1111. Diagnosis was confirmed in 929 cases. Among 921 with known diagnosis dates, median survival was 7.7 months (95% CI 7.1 to 8.3). It was 9.4 months (7.1 to 10.7) for epithelioid, 7.9 (6.6 to 9.2) for biphasic and 4.1 (3.2 to 5.0) for sarcomatoid subtypes. Those given both radical surgery and chemotherapy had a median of 15.1 months (12.0 to 19.0); those given neither, 4.1 (3.4 to 4.8). From 2003–2005 to 2006–2008, chemotherapy use rose from 258 of 605 patients to 191 of 324, and median survival, by year of death, from 7.5 months (6.7 to 8.3; n 600) to 8.1 (7.1 to 9.0; n 321). In pleural mesothelioma, age under 70, female gender, epithelioid subtype and stage I to III were independent favorable factors. The authors cautioned that treatment choice may be biased by age, stage and physical condition. They concluded that survival had increased due to improved diagnosis and more widespread treatment.

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: Nationwide retrospective survey using death records and the medical information of people who died of malignant mesothelioma
• Who was studied: 929 people with a confirmed diagnosis of malignant mesothelioma who died in Japan between 2003 and 2008. They were drawn from 6030 mesothelioma deaths in Japan's Vital Statistics. Relatives' consent was obtained for 2069, and medical information (medical records, x-ray films and/or CT images) was obtained for 1111. The 929 were 753 males and 176 females, with a median age at diagnosis of 67.0 years (range 16 to 94). The tumor arose in the pleura in 794, the peritoneum in 123, the pericardium in 7 and the testicular tunica vaginalis in 5.
• Exposure: Treatment received: radical surgical resection (172 cases, 18.5%; extrapleural pneumonectomy in 103 of the 154 operated pleural cases), systemic chemotherapy (449 cases, 48.3%), or palliative treatment only (374 cases, 40.3%). Asbestos exposure was not analyzed in this paper.
• Main results:
  • Median overall survival among the 921 cases with a known diagnosis date was 7.7 months (95% CI 7.1 to 8.3).
  • Median survival was 7.9 months (95% CI 7.3 to 8.5) for pleural mesothelioma (n 789) and 4.7 months (3.8 to 5.7) for peritoneal mesothelioma (n 123). The difference was not statistically significant (p value 0.069).
  • Across all sites, median survival was 9.4 months (95% CI 7.1 to 10.7) for the epithelioid subtype, 7.9 months (6.6 to 9.2) for biphasic and 4.1 months (3.2 to 5.0) for sarcomatoid. Epithelioid survival was significantly longer than both biphasic and sarcomatoid survival.
  • Median survival was 15.1 months (95% CI 12.0 to 19.0) with both radical surgery and chemotherapy (group A), 8.6 months (6.6 to 10.5) with surgery only (B), 9.3 months (8.4 to 10.2) with chemotherapy only (C), and 4.1 months (3.4 to 4.8) with neither (D).
  • The proportion treated with systemic chemotherapy rose from 42.6% (258 of 605 cases) in the early phase (2003–2005) to 59.0% (191 of 324 cases) in the late phase (2006–2008).
  • Median survival was 8.1 months (95% CI 7.1 to 9.0) for patients who died in 2006–2008 (n 321) and 7.5 months (6.7 to 8.3) for those who died in 2003–2005 (n 600), with a p value of 0.008.
  • In patients with pleural mesothelioma, age under 70, epithelioid subtype and stage I to III were favorable factors on univariate analysis. These factors and female gender were independent favorable factors on multivariate analysis. Gender alone was not significant on univariate analysis (p 0.6435).
  • When treatment was added to the multivariate analysis for pleural mesothelioma, both radical surgery and systemic chemotherapy were associated with longer survival.
• The authors' conclusion: The authors concluded that survival of mesothelioma patients in Japan had increased due to improved definitive diagnosis and more widespread treatment. They said new approaches to early diagnosis and treatment are needed to improve survival further.
• Limitations the authors state:
  • The authors acknowledged a low collection rate from the postal-mail method of gathering data, though they stated there was no selection bias in the data collection process.
  • The authors said the survival benefits linked to surgery and chemotherapy should be interpreted with caution, because the choice of therapy may be biased by patient factors.
  • Cisplatin/pemetrexed appeared inferior to cisplatin/gemcitabine (hazard ratio 1.62, 95% CI 1.06 to 2.45). The authors attributed this to pemetrexed being approved in Japan only in 2007, so long survivors on that regimen were not included among the deaths through 2008.

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: Mesothelioma, Histological Subtype, Epithelioid, Sarcomatoid, Biphasic Mesothelioma, Median Overall Survival, confidence interval, Surgical Resection.

Related studies

• Survival and prognostic factors in malignant pleural mesothelioma: a retrospective study of 314 patients in the west part of Japan — S. Nojiri, K. Gemba, et al. (2011)
• Fatal pleural mesothelioma in Japan (2003-2008): evaluation of computed tomography findings — K. Kato, K. Gemba, et al. (2016)
• National survey of malignant mesothelioma and asbestos exposure in Japan — K. Gemba, N. Fujimoto, et al. (2012)
• Clinical investigation of malignant mesothelioma in Japan — N. Fujimoto, K. Aoe, et al. (2010)
• Incidence of interstitial lung disease in patients with mesothelioma in the west part of Japan — S. Nojiri, K. Gemba, et al. (2011)
• Quality of life of survivors of malignant pleural mesothelioma in Japan: a cross sectional study — Y. Nagamatsu, I. Oze, et al. (2018)

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