Determinants of Survival in Malignant Pleural Mesothelioma: A Surveillance, Epidemiology, and End Results (SEER) Study of 14,228 Patients

Our plain-English summary of Determinants of Survival in Malignant Pleural Mesothelioma: A Surveillance, Epidemiology, and End Results (SEER) Study of 14,228 Patients, by E. Taioli, A.S. Wolf, M. Camacho-Rivera, et al (PloS One, 2015).

The study

• Authors: E. Taioli, A.S. Wolf, M. Camacho-Rivera, A. Kaufman, D.S. Lee, D. Nicastri, K. Rosenzweig, R.M. Flores
• Journal: PloS One
• Published: 2015;10(12):e0145039
• Cited by: 126 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Introduction: Left untreated, malignant pleural mesothelioma (MPM) is associated with uniformly poor prognosis. Better survival has been reported with surgery-based multimodality therapy, but to date, no trial has demonstrated survival benefit of surgery over other therapies. We evaluated whether cancer-directed surgery influenced survival independently from other predictors in a large population-based dataset.

Methods: The SEER database was explored from 1973 to 2009 to identify all cases of pathologically-proven MPM. Age, sex, race, year of diagnosis, histology stage, cancer-directed surgery, radiation, and vital status were analyzed. The association between prognostic factors and survival was estimated using Cox regression and propensity matched analysis.

Results: There were 14,228 patients with pathologic diagnosis of MPM. On multivariable analysis, female gender, younger age, early stage, and treatment with surgery were independent predictors of longer survival. In comparison to no treatment, surgery alone was associated with significant improvement in survival [adjusted hazard ratio (adj HR) 0.64 (0.61-0.67)], but not radiation [adj HR 1.15 (1.08-1.23)]. Surgery and radiation combined had similar survival as surgery alone [adj HR 0.69 (0.64-0.76)]. Results were similar when cases diagnosed between 1973 and 1999 were compared to cases diagnosed between 2000 and 2009.

Conclusions: Despite developments in surgical and radiation techniques, the prognosis for MPM patients has not improved over the past 4 decades. Cancer-directed surgery is independently associated with better survival, suggesting that multimodal surgery-based therapy can benefit these patients. Further research in adjuvant treatment is necessary to improve prognosis in this challenging disease.

In plain English

This study used the US Surveillance, Epidemiology, and End Results (SEER) cancer registry to look at what was linked to survival in 14,228 adults with pathologically confirmed malignant pleural mesothelioma diagnosed from 1973 to 2009. It did not examine asbestos exposure. Only 23% of patients had cancer-directed surgery and 13% had radiation. Median overall survival was 7 months, and 91% had died by the end of follow-up. After adjusting for other factors, being female, younger age and earlier stage were linked to longer survival. Patients who had neither surgery nor radiation were the comparison group. Against them, surgery alone was associated with a lower risk of death (adjusted hazard ratio 0.64, 95% CI 0.61 to 0.67), and radiation alone with a higher risk (1.15, 1.08 to 1.23). Surgery plus radiation was also associated with a lower risk (0.69, 0.64 to 0.76). Median survival was 14.5 months with surgery alone and 6.5 months with neither treatment. The authors concluded that surgery was independently associated with better survival. They said SEER lacks data on comorbidities, chemotherapy and treatment intent.

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 US population-based cancer registry (SEER), using Cox regression and a propensity-matched analysis
• Who was studied: 14,228 adults (18 or older) with pathologically proven malignant mesothelioma of the pleura and lung in SEER registries, diagnosed 1973 to 2009. 78% were male and 92% white. Other mesothelioma sites, including peritoneal, were excluded.
• Exposure: Treatment received (cancer-directed surgery, radiation, both, or neither), along with age, sex, race, year of diagnosis, stage and histology. Asbestos exposure was not recorded or analyzed; asbestos is mentioned only as background in the introduction.
• Main results:
  • 23% of all patients (3,307 of 14,228) received cancer-directed surgery and 13% (1,805) received radiation
  • Median overall survival for all patients was 7 months; 91% (12,902) had died by the end of follow-up
  • Female patients compared with male patients: adjusted HR 0.79 (95% CI 0.75 to 0.82)
  • Distant compared with localized disease: adjusted HR 1.4 (95% CI 1.31 to 1.49); risk rose with increasing age (adjusted HR 1.02 per year)
  • Patients diagnosed 2005 to 2009 compared with 1973 to 1989: adjusted HR 0.81 (95% CI 0.77 to 0.86)
  • Surgery alone compared with no surgery or radiation: adjusted HR 0.64 (95% CI 0.61 to 0.67)
  • Radiation alone compared with no surgery or radiation: adjusted HR 1.15 (95% CI 1.08 to 1.23)
  • Surgery plus radiation compared with no surgery or radiation: adjusted HR 0.69 (95% CI 0.64 to 0.76)
  • Median survival: 6.5 months with no surgery or radiation, 7.5 months with radiation, 14.5 months with surgery, and 13 months with both
  • In the propensity analysis matched on sex, stage and age, the HR for surgery was 0.68 (95% CI 0.66 to 0.72), compared with 0.64 (0.61 to 0.67) in the unmatched data
  • Patients diagnosed 1973 to 1999, each compared with no surgery or radiation: radiation 1.14 (95% CI 1.05 to 1.23), surgery 0.63 (0.59 to 0.68), surgery plus radiation 0.75 (0.66 to 0.84). The authors reported similar results for 2000 to 2009.
• The authors' conclusion: The authors concluded that cancer-directed surgery, alone or with radiation, was independently associated with better survival, suggesting surgery-based multimodal therapy can benefit these patients. They also stated that prognosis had not improved over the past four decades.
• Limitations the authors state:
  • Factors used to select patients for surgery (performance status, lung and heart function, comorbidities) are not recorded in SEER and could affect survival
  • SEER does not record whether treatment was curative or palliative, or whether, what, or how much chemotherapy was given
  • Radiation details such as dose and fields are not available
  • The sequence of treatments is not recorded
  • SEER includes both general hospitals and specialized cancer centers, where surgical techniques may differ

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, SEER, Prognosis, Multimodal Therapy, Histology, Hazard Ratio.

Related studies

• 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)
• Survival analysis via nomogram of surgical patients with malignant pleural mesothelioma in the Surveillance, Epidemiology, and End Results database — M. Zhuo, Q. Zheng, et al. (2019)
• 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)
• Addition of radiotherapy to surgery and chemotherapy improves survival in localized malignant pleural mesothelioma: A Surveillance, Epidemiology, and End Results (SEER) study — A.B. Thompson, T.J. Quinn, et al. (2020)
• Women with malignant pleural mesothelioma have a threefold better survival rate than men — E. Taioli, A.S. Wolf, et al. (2014)
• 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)

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