Surgical approach to pleural diffuse mesothelioma in Japan

Our plain-English summary of Surgical approach to pleural diffuse mesothelioma in Japan, by K. Takagi, R. Tsuchiya, Y. Watanabe (Lung Cancer, 2001).

The study

• Authors: K. Takagi, R. Tsuchiya, Y. Watanabe
• Journal: Lung Cancer
• Published: 2001;31(1):57-65
• Cited by: 26 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The current status of the surgical treatment of patients with pleural diffuse mesothelioma in Japan was surveyed from the results of a questionnaire sent to members of The Japanese Association for Chest Surgery. Physicians at 57 institutions returned the questionnaire, and a total of 189 surgical cases of diffuse mesothelioma between 1987 and 1996 were analyzed. The age of the patients ranged between 18 and 80 years. They consisted of 154 males and 33 females (the gender of two patients was not indicated). By histological type, 104 cases had the epithelial type, 29 cases had the sarcomatous type, and 46 cases had the mixed type of diffuse mesothelioma (the histology of 10 patients was not indicated). As to the type of surgery, pleuropneumonectomy was performed in 116 cases (61%), and limited resection [including decortication (5 cases) and tumorectomy (68 cases)] was performed in 73 cases (39%). The goal of pleuropneumonectomy is radical resection of the tumor, which often requires combined resection of adjacent structures. The tumor was completely removed macroscopically in 84 (72%) of the 116 cases who underwent pleuropneumonectomy; however, among those with an epithelial-type tumor that was completely removed by pleuropneumonectomy, the tumor recurred postoperatively in 43% of these patients. Perioperative adjuvant therapy was performed in 83 of the 116 patients who underwent pleuropneumonectomy. The 2-year and 5-year survival rates of those who had undergone pleuropneumonectomy were 29.7 and 9.1%, respectively, and the perioperative mortality rate of this procedure was 6%. Limited resection, on the other hand, did not involve radical resection of the tumor. The 2-year and 5-year survival rates of the patients who had undergone limited resection were 26.1 and 9.5%, respectively, and the perioperative mortality rate was 6%. The survival rates and perioperative mortality rate of the patients who had undergone pleuropneumonectomy or limited resection did not significantly differ. The prognostic factors for survival included gender (P=0.0019) and adjuvant therapy (P=0.0034) by Cox's Regression Analysis. The goals of surgical treatment of pleural diffuse mesothelioma are relief of symptoms and prolongation of survival time. Selecting the appropriate surgical procedure and more effective adjuvant therapy for each particular case is necessary under a new, accurate staging system for diffuse mesothelioma.

In plain English

This retrospective study covered 189 patients operated on for pleural diffuse mesothelioma in Japan between 1987 and 1996. Physician members of the Japanese Association for Chest Surgery were sent a questionnaire, and physicians at 57 of 141 institutions replied. The article does not report asbestos exposure. Of the 189 patients, 116 had pleuropneumonectomy, an operation aimed at removing all of the tumor, and 73 had limited resection (decortication or tumorectomy). Two-year and 5-year survival was 29.7% and 9.1% after pleuropneumonectomy, and 26.1% and 9.5% after limited resection. Survival curves did not significantly differ between the operations, and each had a 30-day mortality of 6%. Among 46 epithelial-type patients whose tumor was visibly (macroscopically) completely removed by pleuropneumonectomy, 43% had local recurrence. In multivariable analysis, being female and receiving adjuvant therapy were significant prognostic factors. Survival curves for the three tumor types were similar, and the epithelial type did not do significantly better than the sarcomatous or mixed types. The authors said they could not determine which adjuvant treatments were effective. They added that whether adjuvant therapy itself works is difficult to determine, because prognosis depends on many factors. They concluded that a more accurate staging system is needed.

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 surgical cases collected by a questionnaire sent to physician members of a national surgical association
• Who was studied: 189 patients surgically treated for pleural diffuse mesothelioma between 1987 and 1996. Questionnaires were returned by 57 physicians at 57 of 141 institutions. Patients were aged 18 to 80: 154 males and 33 females (sex not given for 2). Tumor types were 104 epithelial, 29 sarcomatous and 46 mixed (histology not given for 10).
• Exposure: The study did not examine asbestos exposure, which the article does not report. It compared operations: pleuropneumonectomy (116 patients) versus limited resection, meaning decortication (5) or tumorectomy (68). Patients had surgery with or without perioperative adjuvant therapy (radiation, systemic chemotherapy and/or intrapleural injection).
• Main results:
  • Pleuropneumonectomy patients: 2-year survival 29.7%, 5-year survival 9.1%
  • 5-year survival was 9.1% after pleuropneumonectomy and 9.5% after limited resection (2-year survival after limited resection was 26.1%). The survival curves did not significantly differ.
  • 30-day mortality was 6% for both pleuropneumonectomy and limited resection
  • Median survival among all 189 patients was 12 months
  • The tumor was completely removed macroscopically in 84 of the 116 pleuropneumonectomy cases (72%)
  • Among 46 patients with epithelial type who had complete (macroscopic) resection by pleuropneumonectomy, local recurrence occurred in 43% and distant metastasis in 39%
  • Patients who received adjuvant therapy had significantly better survival than those who did not (log-rank P=0.0023)
  • Patients under 50 at surgery had significantly better survival than those 50 or older (P=0.007)
  • Among pleuropneumonectomy patients, females had significantly better survival than males (P=0.0160). Among limited resection patients, the difference was marginal (P=0.0587).
  • In Cox regression, being female (P=0.0019) and receiving adjuvant therapy (P=0.0034) were prognostic factors for survival
  • Survival curves by histological type were similar. Epithelial-type patients did not have significantly better survival than sarcomatous or mixed-type patients.
  • Of seven patients who survived more than 5 years, six were female
• The authors' conclusion: The authors concluded that survival and perioperative mortality did not significantly differ between pleuropneumonectomy and limited resection, even in the epithelial type. They also concluded that:
• pleuropneumonectomy had a high local recurrence rate;
• adjuvant therapy was associated with better prognosis;
• an accurate and more practical staging system is required.
• Limitations the authors state:
  • Adjuvant therapy included many types of treatment, so the authors could not determine which were effective. Patient backgrounds also varied.
  • Whether adjuvant therapy is actually effective is hard to determine, because prognosis depends on many factors
  • Lymph node data were not collected, so lymph node metastasis could not be analyzed
  • Diagnostic criteria for histological type may have differed between institutions

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, Histology, Adjuvant Therapy, Staging.

Related studies

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• Patterns of care and survival among patients with malignant mesothelioma in the United States — L. Enewold, E. Sharon, et al. (2017)
• The importance of surgical staging in the treatment of malignant pleural mesothelioma — V.W. Rusch, E. Venkatraman (1996)
• Malignant pleural mesothelioma in parts of Japan in relationship to asbestos exposure — T. Kishimoto, S. Ozaki, et al. (2004)
• Clinical investigation of malignant mesothelioma in Japan — N. Fujimoto, K. Aoe, et al. (2010)
• National survey of malignant mesothelioma and asbestos exposure in Japan — K. Gemba, N. Fujimoto, et al. (2012)

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