Survival analysis via nomogram of surgical patients with malignant pleural mesothelioma in the Surveillance, Epidemiology, and End Results database

Our plain-English summary of Survival analysis via nomogram of surgical patients with malignant pleural mesothelioma in the Surveillance, Epidemiology, and End Results database, by M. Zhuo, Q. Zheng, Y. Chi, et al (Thoracic Cancer, 2019).

The study

• Authors: M. Zhuo, Q. Zheng, Y. Chi, B. Jia, J. Zhao, M. Wu, T. An, Y. Wang, J. Li, X. Zhao, X. Yang, J. Zhong, H. Chen, Z. Dong, J. Wang, X. Zhai, Z. Wang
• Journal: Thoracic Cancer
• Published: 2019;10(5):1193-1202
• Cited by: 17 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Malignant pleural mesothelioma (MPM) is a rare but aggressive tumor that originates from the pleura and has a poor prognosis. Eligible patients can benefit from surgery, but their survival is affected by many factors. Therefore, we created a graphic model that could predict the prognosis of surgically treated patients.

Methods: We retrospectively analyzed data from the Surveillance, Epidemiology, and End Results database from 2004 to 2014 to identify the key factors affecting the prognosis of surgically treated MPM patients. On this basis we built a nomogram to predict survival. We then evaluated the performance of the nomogram in a validation cohort.

Results: In a training cohort of 828 cases, independent prognostic factors, including age, gender, histological type, differentiation, N stage, chemotherapy, type of surgery, and lymph node dissection, were identified. We then developed a nomogram to evaluate individual patient survival. In Kaplan-Meier analysis, a higher score in the nomogram was associated with a worse prognosis. We also used a validation cohort consisting of 312 patients to evaluate the performance of the nomogram, which was well calibrated and had good discrimination ability, with concordance indices of 0.715 and 0.656 for the training and validation cohorts, respectively.

Conclusion: This study has improved our understanding of resected MPM and shown that key factors, including age and histological type, are associated with overall survival. The nomogram is a reliable tool that can help clinicians turn individualized prediction into reality and maximize patient benefit by identifying the most beneficial treatment approach.

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

In plain English

This retrospective study used records from the US SEER cancer registry. The authors identified 1,140 adults with malignant pleural mesothelioma diagnosed between 2004 and 2014 who had surgery. Most operations were palliative rather than radical. The authors used 828 patients diagnosed in 2004 to 2011 to build a nomogram, a chart predicting one- and three-year overall survival. They tested it on 312 patients diagnosed in 2012 to 2014. Median overall survival for all 1,140 patients was 14 months (95% CI 13 to 15 months). In the building group, shorter survival was linked to male gender, fibrous histology, poor differentiation, N2 lymph node stage, no chemotherapy, and no or unknown lymph node dissection. Epithelioid histology was linked to longer survival. Surgery type was not statistically significant. The chart's C-index, which measures how well it separated patients by outcome, was 0.715 (95% CI 0.698 to 0.736) in the building group and 0.656 (95% CI 0.645 to 0.667) in the test group, both higher than TNM staging. The authors concluded the nomogram is a reliable tool. The article did not report asbestos exposure.

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 population-based cancer registry (SEER), with development of a survival nomogram from Cox regression in a training cohort and testing in a separate validation cohort
• Who was studied: 1140 patients aged over 18 with malignant pleural mesothelioma in the US SEER database who had surgery, diagnosed 2004 to 2014. They were selected from 4372 pleural cases after excluding 21 with no survival data and 3211 with no or unknown cancer-directed surgery. The training cohort was 828 patients diagnosed 2004 to 2011 (median age 67, 78.1% male). The validation cohort was 312 patients diagnosed 2012 to 2014 (median age 70, 75.0% male).
• Main results:
  • Among all 1140 surgical patients, median overall survival was 14 months (95% CI 13 to 15 months).
  • Among all 1140 surgical patients, overall survival was 53.9% at one year, 17.1% at three years and 8.5% at five years.
  • In the training cohort (multivariable analysis), male gender was associated with worse survival than female gender: HR 1.486, 95% CI 1.241 to 1.779.
  • In the training cohort (multivariable analysis), epithelioid histology was associated with better survival than biphasic histology: HR 0.682, 95% CI 0.543 to 0.855.
  • In the training cohort (multivariable analysis), fibrous histology was associated with worse survival than biphasic histology: HR 1.478, 95% CI 1.088 to 2.005.
  • In the training cohort (multivariable analysis), poorly differentiated tumors were associated with worse survival than well or moderately differentiated tumors: HR 2.312, 95% CI 1.362 to 3.921.
  • In the training cohort (multivariable analysis), N2 lymph node stage was associated with worse survival than N0: HR 1.409, 95% CI 1.155 to 1.718.
  • In the training cohort (multivariable analysis), treatment without chemotherapy was associated with worse survival: HR 1.319, 95% CI 1.130 to 1.538.
  • In the training cohort (multivariable analysis), no or unknown lymph node dissection was associated with worse survival than removal of 1 to 3 nodes: HR 1.350, 95% CI 1.025 to 1.776.
  • In the training cohort, palliative surgery compared with surgery of unspecified type was not statistically significant (HR 1.234, 95% CI 0.868 to 1.753). The authors described surgery type as tending to be associated with prognosis.
  • Age had a nonlinear relationship with risk of death, with the youngest and oldest ages showing the highest mortality risk.
  • Training-cohort patients grouped into quartiles of nomogram score had different one-year survival: 74.9% in quartile 1, 63.5% in quartile 2, 52.4% in quartile 3 and 13.3% in quartile 4 (P less than 0.001).
  • In the training cohort, the nomogram's C-index was 0.715 (95% CI 0.698 to 0.736). This was higher than the TNM staging system's 0.564 (95% CI 0.539 to 0.589; P less than 0.01).
  • In the validation cohort of 312 patients, the nomogram's C-index was 0.656 (95% CI 0.645 to 0.667). This was higher than the TNM system's 0.543 (95% CI 0.532 to 0.554; P less than 0.01).
  • The authors found no significant association between overall survival and TNM staging.
• The authors' conclusion: The authors concluded that their results improve understanding of resected malignant pleural mesothelioma and that the nomogram is a reliable tool for predicting overall survival. They also suggested caution about surgery in patients over 70.
• Limitations the authors state:
  • The study was retrospective, and the authors said large randomized controlled trials are needed to confirm the findings.
  • Other factors that affect surgical outcome, such as cardiopulmonary conditions and comorbidities, are not recorded in SEER.
  • SEER lacked details of chemotherapy regimens and radiation doses, so these could not be analyzed.

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, Epidemiology, Pleura, Prognosis, Chemotherapy, Overall Survival.

Related studies

• The revised staging system for malignant pleural mesothelioma based on surveillance, epidemiology, and end results database — S. Wang, K. Ma, et al. (2017)
• A novel nomogram for peritoneal mesothelioma predicts survival — N.P. Schaub, M. Alimchandani, et al. (2013)
• A Nomogram to Predict Prognosis in Malignant Pleural Mesothelioma — S. Wang, K. Ma, et al. (2018)
• Frequency of use and predictors of cancer-directed surgery in the management of malignant pleural mesothelioma in a community-based (Surveillance, Epidemiology, and End Results [SEER]) population — R.M. Flores, E. Riedel, et al. (2010)
• Mesothelioma trends in the United States: an update based on Surveillance, Epidemiology, and End Results Program data for 1973 through 2003 — B. Price, A. Ware (2004)
• Mesothelioma in the United States: a Surveillance, Epidemiology, and End Results (SEER)-Medicare investigation of treatment patterns and overall survival — J.L. Beebe-Dimmer, J.P. Fryzek, et al. (2016)

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