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

Our plain-English summary of 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, by R.M. Flores, E. Riedel, J.S. Donington, et al (Journal of Thoracic Oncology, 2010).

The study

• Authors: R.M. Flores, E. Riedel, J.S. Donington, W. Alago, U. Ihekweazu, L. Krug, K. Rosenzweig, P.S. Adusumilli, M. Carbone, H.I. Pass
• Journal: Journal of Thoracic Oncology
• Published: 2010;5(10):1649-54
• Cited by: 62 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Introduction: Surgical intervention rates for mesothelioma patients treated at specialized tertiary hospitals are well more than 42%. Mesothelioma surgical strategies in the community are less well defined. This study evaluates the frequency of use and predictors of cancer-directed surgical intervention in a nontertiary-based population and the predictors for surgical intervention.

Methods: The Surveillance, Epidemiology, and End Results database was searched from 1990 to 2004. Variables analyzed included age, sex, race, year of diagnosis, region, vital status, stage, surgery, and reasons for no surgery. The association of patient variables on receipt of cancer-directed surgery was evaluated using χ(2) tests and logistic regression. The incidence of mesothelioma was also evaluated over this period of time.

Results: Pathologically proven malignant pleural mesothelioma was identified in 1166 women and 4771 men. The rate of cancer-directed surgery was 22% (n = 1317). Significant predictors of receiving cancer-directed surgery included race, age, and stage (all p < 0.0001). A landmark analysis on the effect of cancer-directed surgery on survival after adjusting for patient and disease characteristics demonstrated a hazard ratio of 0.68 (p < 0.0001). The incidence rate of malignant pleural mesothelioma has remained constant.

Conclusions: The rate of surgical intervention in the community is lower compared with tertiary referral centers. Age, stage, and race predict the likelihood of receiving cancer-directed surgery. A lower rate of cancer-directed surgery and worse overall outcome were observed in black patients. As part of quality assurance, referral of patients to centers with multidisciplinary programs that include thoracic surgical expertise should be considered.

In plain English

This study used SEER, a population-based US cancer registry, to see how often people with malignant pleural mesothelioma had cancer-directed surgery; how many were treated at specialist centers was unknown. It included 5937 pathologically proven cases diagnosed from 1990 to 2004. Asbestos exposure was not examined. Overall, 1317 patients (22%) had cancer-directed surgery; for 3383, surgery was not recommended. Younger patients were more likely to have surgery, and patients with distant-stage disease were less likely. Black patients were less likely than white patients to have surgery (adjusted odds ratio 0.45, 95% confidence interval 0.31 to 0.64; a table gives 0.32 to 0.65). They also more often presented with advanced disease. Median survival was 8 months (95% confidence interval 7 to 8). From 2 months after diagnosis, surgery was associated with a lower risk of death (adjusted hazard ratio 0.68, 95% confidence interval 0.63 to 0.74). The authors noted remaining bias favoring surgical patients and said one treatment could not be shown better. The authors concluded that surgery rates in the community were lower than at tertiary referral centers.

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 US cancer registry (SEER)
• Who was studied: 5937 patients with pathologically proven malignant pleural mesothelioma (4771 men, 1166 women) in SEER registry areas of the United States, diagnosed 1990 to 2004. Postmortem cases, cases not confirmed microscopically, and peritoneal and other non-pleural sites were excluded. The number treated at tertiary referral centers is unknown.
• Exposure: The factor studied was receipt of cancer-directed surgery, plus patient and disease characteristics linked to receiving it. Asbestos or fiber exposure was not studied.
• Main results:
  • 1317 of the 5937 patients (22%) underwent cancer-directed surgery. The most common type was partial removal of the primary cancer site (486 patients, 37% of those operated on). Only 3 pneumonectomies were recorded.
  • Of the 4587 patients who did not have surgery, 3383 did not have surgery recommended, surgery was contraindicated in 200, 65 refused, and 2 died before planned surgery. The reason was unknown in 937. The printed percentages (for example 57%) appear to be calculated on all 5937 patients.
  • Younger patients were more likely to receive cancer-directed surgery. The adjusted odds ratio was 0.84 (95% CI 0.81 to 0.86) per 5-year increase in age.
  • Compared with early-stage patients, patients with distant disease were less likely to receive surgery (adjusted odds ratio 0.52, 95% CI 0.40 to 0.67). For late-stage patients the adjusted odds ratio was 0.92 (95% CI 0.75 to 1.13).
  • Black patients were less likely than white patients to have cancer-directed surgery. The text gives an odds ratio of 0.45 (95% CI 0.31 to 0.64); Table 2 gives an adjusted odds ratio of 0.45 (0.32 to 0.65). Of black patients, 42 of 292 (14%) had surgery, compared with 1233 of 5404 (23%) of white patients.
  • Patients who received radiation were more likely to have surgery: 321 of 835 (38%), compared with 959 of 4970 (19%) of patients without radiation. The adjusted odds ratio was 2.51 (95% CI 2.12 to 2.97).
  • 804 of the 5937 patients (14%) were alive at last follow-up. Median overall survival for all patients was 8 months (95% CI 7 to 8 months).
  • In the analysis starting 2 months after diagnosis (923 patients died before that point), cancer-directed surgery was associated with improved survival. The hazard ratio was 0.68 (95% CI 0.63 to 0.74), adjusted for age, stage, race and sex. In this model, black race was not statistically significant (hazard ratio 1.15, 95% CI 0.99 to 1.34).
  • In the survival model without treatment variables, stage, sex, age and race were each independently associated with overall survival. Men had an adjusted hazard ratio of 1.21 (95% CI 1.12 to 1.30) compared with women. Black patients had 1.29 (95% CI 1.13 to 1.47) compared with white patients.
  • Black patients more often presented with advanced stage: 24% of black patients had distant-stage disease, compared with 17% of white patients. The p value is printed as 0.009, with the comparison symbol lost in the text.
  • Age-adjusted incidence of malignant pleural mesothelioma in the SEER areas stayed between 0.9 and 1.2 per 100,000 per year from 1990 to 2004. The authors estimated about 3300 new US cases per year.
• The authors' conclusion: The authors concluded that the rate of surgery among mesothelioma patients in the community was lower than at tertiary referral centers. They found that younger patients with early-stage disease had surgery more often, and that surgery rates and overall outcome were lower in black patients. They recommended evaluation by a multidisciplinary team including thoracic surgical consultation.
• Limitations the authors state:
  • Selection and lead-time bias favoring surgically treated patients remained, despite the 2-month landmark analysis.
  • The study lacked chemotherapy data and detailed radiotherapy and surgical data, and did not stratify by histologic subtype.
  • Because the study was observational, it could not determine whether one treatment is superior to another.
  • The date of surgery is not recorded in SEER, and the details of the surgical procedure are unclear in SEER coding.
  • The number of SEER patients treated at tertiary referral centers is unknown.

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, Epidemiology, SEER, Mesothelioma, Hazard Ratio, Incidence.

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• Is There a Role for Cancer-Directed Surgery in Early-Stage Sarcomatoid or Biphasic Mesothelioma? — S. Kim, D.A. Bull, et al. (2019)
• Frequency of Surgery in Black Patients with Malignant Pleural Mesothelioma — E. Taioli, A.S. Wolf, et al. (2015)
• 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)
• Polymorphism of glutathione S-transferase M1 and lung cancer risk among African-Americans and Caucasians in Los Angeles County, California — S.J. London, A.K. Daly, et al. (1995)
• Time trend of mesothelioma incidence in the United States and projection of future cases: an update based on SEER data for 1973 through 2005 — B. Price, A. Ware (2009)

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