Epithelial malignant pleural mesothelioma after extrapleural pneumonectomy: stratification of survival with CT-derived tumor volume

Our plain-English summary of Epithelial malignant pleural mesothelioma after extrapleural pneumonectomy: stratification of survival with CT-derived tumor volume, by R.R. Gill, W.G. Richards, B.Y. Yeap, et al (AJR. American Journal of Roentgenology, 2012).

The study

• Authors: R.R. Gill, W.G. Richards, B.Y. Yeap, S. Matsuoka, A.S. Wolf, V.H. Gerbaudo, R. Bueno, D.J. Sugarbaker, H. Hatabu
• Journal: AJR. American Journal of Roentgenology
• Published: 2012;198(2):359-63
• Cited by: 73 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objective: The purpose of this study was to assess the usefulness of CT-derived tumor volume, with control for other prognostic factors, for stratifying survival after surgery-based multimodality treatment of a large cohort of patients with epithelial malignant pleural mesothelioma.

Materials And Methods: We retrospectively reviewed 338 patients with mesothelioma who underwent extrapleural pneumonectomy between 2001 and 2007. The study cohort comprised 88 patients with epithelial subtype tumors, DICOM-format CT scans, and data regarding neoadjuvant and adjuvant therapy. Tumor volume was calculated, and Kaplan-Meier survival and Cox regression analyses were performed to compare the estimated survival functions of patient subgroups based on volume and other covariates related to outcome (sex, age, preoperative platelet count, hemoglobin concentration, WBC count, clinical and pathologic TNM category, and administration of neoadjuvant and adjuvant therapy). A multivariate regression model was derived on the basis of the most significant univariate predictors.

Results: The median estimated tumor volume was 319 cm(3) (range, 4-3256 cm(3)). In univariate analysis, tumor volume, hemoglobin concentration, platelet count, pathologic TNM category, and administration of adjuvant chemotherapy or radiation therapy met the criteria for inclusion in the reverse stepwise regression analysis. In the final model, tumor volume, hemoglobin concentration, and administration of adjuvant chemotherapy or radiotherapy were identified as independently associated with overall survival.

Conclusion: With control of prognostic covariates, CT-derived tumor volume can be used to stratify survival of patients with epithelial mesothelioma after extrapleural pneumonectomy and should be included in prognostic evaluation of patients for whom resection is being considered.

In plain English

This retrospective study asked whether tumor volume, measured on CT scans before surgery, was linked to survival after extrapleural pneumonectomy for malignant pleural mesothelioma. From 338 patients who had this operation between 2001 and 2007, the authors studied 88 with the epithelial tumor type, usable CT scans and records of whether they received chemotherapy or radiotherapy after surgery. Asbestos exposure was not studied. Median survival for the whole group was 18.7 months. The 59 patients with tumors of 500 cm3 or less had a median survival of 24.4 months, against 12 months for the 29 with larger tumors (p less than 0.0001). In the final model, three factors were independently associated with survival. A tumor volume above 500 cm3 (hazard ratio 2.02, 95% CI 1.18 to 3.47) and anemia (hazard ratio 1.99, 95% CI 1.19 to 3.33) were associated with shorter survival. Chemotherapy or radiotherapy after surgery (hazard ratio 0.30, 95% CI 0.18 to 0.52) was associated with longer survival. The authors concluded that tumor volume should be part of routine assessment of patients with epithelial mesothelioma being considered for this surgery. They noted that the study was retrospective and that its patients were selected on the basis of available data.

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 cohort study (review of registry and chart data) with Kaplan-Meier and Cox regression survival analysis
• Who was studied: 88 patients (66 men, 22 women; median age 61, range 31 to 78) with epithelial-type malignant pleural mesothelioma who underwent extrapleural pneumonectomy between 2001 and 2007. They were drawn from 338 such surgical patients in the International Mesothelioma Program Patient Data Registry. All 88 had usable preoperative CT scans and complete data on whether adjuvant chemotherapy or radiotherapy was given.
• Exposure: Asbestos exposure was not studied; the article only notes that the disease is asbestos-related. The factor studied was preoperative CT-derived tumor volume, alongside sex, age, blood counts, stage and treatment received.
• Main results:
  • Median overall survival for the whole cohort of 88 patients was 18.7 months.
  • The 59 patients with tumor volume of 500 cm3 or less had a median survival of 24.4 months, versus 12 months for the 29 patients with tumor volume greater than 500 cm3 (p less than 0.0001).
  • In the final multivariate model, tumor volume greater than 500 cm3 had a hazard ratio of 2.02 (95% CI 1.18 to 3.47).
  • In the final multivariate model, anemia had a hazard ratio of 1.99 (95% CI 1.19 to 3.33).
  • In the final multivariate model, adjuvant chemotherapy or radiotherapy had a hazard ratio of 0.30 (95% CI 0.18 to 0.52).
  • Clinical (imaging-based) stage matched the pathologic stage in 31 of the 88 patients (35%), was lower in 49 (56%) and was higher in 8 (9%).
  • Among the 20 patients with both tumor volume greater than 500 cm3 and anemia, 11 (55%) did not receive adjuvant therapy, compared with 17 of the other 68 patients (25%) (p = 0.0154).
• The authors' conclusion: The authors concluded that preoperative CT-derived tumor volume and hemoglobin concentration were independently associated with survival after extrapleural pneumonectomy in epithelial malignant pleural mesothelioma. They recommended that tumor volume estimation be part of routine preoperative assessment of such patients.
• Limitations the authors state:
  • The study was retrospective.
  • The cohort was selected on the basis of available imaging and postoperative data, including complete resection by extrapleural pneumonectomy, epithelial histology and adjuvant therapy data.

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Extrapleural Pneumonectomy (EPP), Mesothelioma, CT Scan, Adjuvant Therapy, Chemotherapy, Overall Survival.

Related studies

• Clinical and pathological features of three-year survivors of malignant pleural mesothelioma following extrapleural pneumonectomy — D.J. Sugarbaker, A.S. Wolf, et al. (2011)
• Extrapleural pneumonectomy in the treatment of epithelioid malignant pleural mesothelioma: novel prognostic implications of combined N1 and N2 nodal involvement based on experience in 529 patients — D.J. Sugarbaker, W.G. Richards, et al. (2014)
• Staging of patients after extrapleural pneumonectomy for malignant pleural mesothelioma--institutional review and current update — C. Cao, S.K. Krog Andvik, et al. (2011)
• Impact of induction therapy on postoperative outcome after extrapleural pneumonectomy for malignant pleural mesothelioma: does induction-accelerated hemithoracic radiation increase the surgical risk? — P. Mordant, K. McRae, et al. (2016)
• Extrapleural pneumonectomy after induction chemotherapy: perioperative outcome in 251 mesothelioma patients from three high-volume institutions — O. Lauk, M.A. Hoda, et al. (2014)
• Patterns of failure, toxicity, and survival after extrapleural pneumonectomy and hemithoracic intensity-modulated radiation therapy for malignant pleural mesothelioma — D.R. Gomez, D.S. Hong, et al. (2013)

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