CD9 expression as a favorable prognostic marker for patients with malignant mesothelioma

Our plain-English summary of CD9 expression as a favorable prognostic marker for patients with malignant mesothelioma, by V.J. Amatya, Y. Takeshima, K. Aoe, et al (Oncology Reports, 2013).

The study

• Authors: V.J. Amatya, Y. Takeshima, K. Aoe, N. Fujimoto, T. Okamoto, T. Yamada, T. Kishimoto, C. Morimoto, K. Inai
• Journal: Oncology Reports
• Published: 2013;29(1):21-8
• Cited by: 17 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

CD9 is involved in cell growth, adhesion and motility and its expression is reported to be of prognostic significance in various types of human malignancies. We found increased cell migration in the mesothelioma cell lines MSTO-211H and TUM1 following in vitro shRNA-mediated knockdown of CD9 expression. We investigated CD9 expression in 112 malignant pleural mesotheliomas. CD9 expression was observed in 62 of 71 epithelioid, 13 of 20 biphasic and only 1 of 21 sarcomatoid mesotheliomas. Among the epithelioid mesotheliomas (EMs), CD9 expression was observed in all of the 33 cases with a differentiated type (EM-D) and in 29 of the 38 cases with a less-differentiated type (EM-LD). Patients with CD9 expression showed higher 1- and 2-year survival rates (63 and 25%) compared to the patients without CD9 expression (39 and 11%). Univariate analysis revealed that patients with CD9 expression demonstrated a more favorable survival (P=0.0025) along with other clinicopathological factors, including age younger than 60 years, IMIG stage I-II, epithelioid histology, EM-D and patients who underwent extrapleural pneumonectomy or received chemotherapy. Multivariate analysis identified CD9 expression as an independent prognostic factor with a hazard ratio (HR) of 1.99 in the analysis of all mesotheliomas (P=0.0261) and an HR of 2.60 in the analysis of EMs (P=0.0376). CD9 expression is an independent favorable prognostic marker of malignant mesothelioma.

In plain English

This Japanese study asked whether a tumor protein called CD9 was linked to survival in malignant pleural mesothelioma. The article does not discuss asbestos exposure. The authors stained archived tumor tissue from 112 cases (103 men and 9 women) held by Hiroshima University. CD9 was present in 76 of the 112 tumors: 62 of 71 epithelioid, 13 of 20 biphasic and 1 of 21 sarcomatoid. Patients whose tumors showed CD9 had a median survival of 15.1 months, compared with 9 months for those without it. Their 1- and 2-year survival rates were 63.2% and 25.0%, compared with 38.9% and 11.1%. Among CD9-positive tumors, the proportion of cells staining (scores 1 to 3) was not significantly linked to survival. After taking account of age, stage, tumor type and treatment, the authors reported that loss of CD9 was an independent predictor of survival (hazard ratio 1.99, 95% confidence interval 1.08 to 3.82). Among the 71 epithelioid cases alone, the hazard ratio was 2.60 (1.05 to 7.37). In lab-grown mesothelioma cells, reducing CD9 increased cell movement. The authors concluded that CD9 expression is a favorable prognostic marker in mesothelioma.

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: Laboratory study of archived tumor tissue, stained for CD9 and linked to patient survival records, plus experiments on mesothelioma cell lines
• Who was studied: 112 patients with malignant pleural mesothelioma from Hiroshima University pathology archives, Japan: 103 men and 9 women, mean age 65.8 years. In addition, two mesothelioma cell lines (MSTO-211H and TUM1) were studied.
• Exposure: Not asbestos. The factor studied was CD9 protein expression in tumor tissue, measured by immunohistochemistry and scored by the percentage of stained tumor cells. The article gives no information on asbestos exposure.
• Main results:
  • CD9 was found in 62 of 71 epithelioid, 13 of 20 biphasic and 1 of 21 sarcomatoid mesotheliomas (76 of 112 overall).
  • Median survival was 15.1 months in the CD9-positive group and 9 months in the CD9-negative group.
  • 1- and 2-year survival rates were 63.2% and 25.0% in the CD9-positive group, compared with 38.9% and 11.1% in the CD9-negative group.
  • Among CD9-positive tumors, staining scores 1, 2 and 3 showed no significant differences in overall survival.
  • In the multivariate analysis of all cases, the authors reported loss of CD9 expression as an independent predictor of overall survival, with a hazard ratio of 1.99 (95% CI 1.08 to 3.82, P=0.0261).
  • In the multivariate analysis of 71 epithelioid mesotheliomas, CD9 expression was again an independent predictor of overall survival, with a hazard ratio of 2.60 (95% CI 1.05 to 7.37, P=0.0376).
  • In MSTO-211H and TUM1 mesothelioma cell lines, reducing CD9 increased cell migration compared with control cells.
• The authors' conclusion: The authors concluded that CD9 expression is a favorable prognostic marker in patients with mesothelioma.
• Limitations the authors state:
  • Patients who had surgical procedures other than extrapleural pneumonectomy were not included because their numbers were too small for analysis.
  • CD9 was found in only one sarcomatoid case, and sarcomatoid type was itself a strong predictor of survival. The authors therefore said a separate analysis excluding sarcomatoid cases was needed, and they ran one on epithelioid cases.
  • The authors stated that the biological meaning of CD9 loss in sarcomatoid mesothelioma needs further study.

Topics

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

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma, Mesothelioma, Pleural Mesothelioma, Epithelioid, Biphasic Mesothelioma, Sarcomatoid, IMIG, Histology.

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