Prognosis of resected non-small cell lung cancer with pleural plaques on intrathoracic findings

Our plain-English summary of Prognosis of resected non-small cell lung cancer with pleural plaques on intrathoracic findings, by A. Kagimoto, T. Mimura, A. Kamigaichi, et al (BMC Cancer, 2022).

The study

• Authors: A. Kagimoto, T. Mimura, A. Kamigaichi, Y. Yamashita
• Journal: BMC Cancer
• Published: 2022;22(1):469
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: The prognosis of patients with lung cancer who demonstrate pleural plaques intraoperatively, which may be associated with exposure to asbestos, is unclear. Here, we compared the clinicopathological characteristics and prognosis of these patients to those of patients without pleural plaques.

Methods: We included patients who underwent curative-intent resection for non-small cell lung cancer. We retrospectively investigated the relationship of intrathoracic findings of pleural plaques with clinicopathological features and prognosis.

Results: Pleural plaques were found in 121/701 patients (17.3%) during surgery. The incidence of squamous cell carcinoma (P < 0.001) and the pathological stage (P = 0.021) were higher in patients with pleural plaques. Overall survival was significantly worse in patients with pleural plaques (5-year rate; 64.5% vs. 79.3%; P < 0.001), and the same finding was noted in clinical stage I patients (5-year rate; 64.8% vs. 83.4%; P < 0.001). In multivariable analysis, the presence of pleural plaques was a significant predictor of overall survival in patients with clinical stage I (hazard ratio, 1.643; P = 0.036). In the analysis among patients with emphysema more severe than Goddard score 5 points or interstitial pneumonia, overall survival was significantly worse in those with pleural plaques than in those without pleural plaques (5-year rate; 66.3% vs. 49.5%; P < 0.001).

Conclusions: Patients with non-small cell lung cancer who underwent resection and demonstrated pleural plaques intraoperatively had a significantly worse prognosis. It is important to recognize the presence of pleural plaques intraoperatively, and our findings will be useful in determining the treatment and follow-up strategy for such patients with lung cancer and pleural plaques on intrathoracic examination.

© 2022. The Author(s).

In plain English

This retrospective study at one hospital in Kure, Japan, covered 701 patients who had surgery intended to cure non-small cell lung cancer, 2009 to 2020. Surgeons recorded pleural plaques seen inside the chest during surgery. The authors call plaques a reliable marker of past asbestos exposure, but individual exposure was unknown. Plaques were seen in 121 of 701 (17.3%); these patients more often had squamous cell carcinoma and higher pathological stage. Five-year overall survival was 64.5% (95% confidence interval 53.2% to 74.4%) with plaques versus 79.3% (74.7% to 83.2%) without. In clinical stage I patients it was 64.8% (52.2% to 75.7%) versus 83.4% (78.7% to 87.2%). In stage I patients, after adjusting for age, sex, emphysema, interstitial pneumonia and other factors, plaques remained linked to worse overall survival (hazard ratio 1.643, 95% CI 1.033 to 2.615). Non-cancer respiratory deaths were more common with plaques; recurrence and lung cancer deaths did not differ significantly. No one in the cohort developed malignant pleural mesothelioma after lung cancer surgery. The authors concluded these patients had a significantly worse prognosis, noting confounding by sex and smoking.

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 at a single institution
• Who was studied: 701 patients who had curative-intent surgery for non-small cell lung cancer at the National Hospital Organization, Kure Medical Center and Chugoku Cancer Center (Kure, Hiroshima, Japan), April 2009 to March 2020. Patients were excluded if they had induction therapy, if complete resection was not achieved, or if they had clinical stage 0 cancer. Median follow-up was 43 months. Of the 121 patients with plaques, 112 (92.5%) were men, compared with 313 of 580 (54.0%) without plaques.
• Exposure: Pleural plaques seen by surgeons inside the chest during the operation, counted as positive when they extended beyond multiple intercostal spaces. The authors treat plaques as a marker of past asbestos exposure. No information on individual asbestos exposure or fiber type was available.
• Main results:
  • Pleural plaques were found during surgery in 121 of 701 patients (17.3%).
  • Squamous cell carcinoma and higher pathological stage were more frequent in patients with plaques. Squamous cell carcinoma was found in 47 of 121 (38.8%) patients with plaques versus 91 of 580 (15.7%) without.
  • All patients: 5-year overall survival was 64.5% (95% CI 53.2% to 74.4%) with plaques versus 79.3% (95% CI 74.7% to 83.2%) without (P less than 0.001).
  • All patients: 5-year recurrence-free survival was 56.1% (95% CI 45.3% to 66.3%) with plaques versus 70.0% (95% CI 65.2% to 74.3%) without (P less than 0.001).
  • All patients: there were no significant differences in recurrence (P = 0.192) or death from lung cancer (P = 0.115) between the groups.
  • All patients: death from respiratory disease occurred in 12 of 121 (9.9%) patients with plaques versus 21 of 580 (3.6%) without (P = 0.007 in Table 1).
  • Clinical stage I patients: 5-year overall survival was 64.8% (95% CI 52.2% to 75.7%) with plaques versus 83.4% (95% CI 78.7% to 87.2%) without (P less than 0.001).
  • Clinical stage I patients, multivariable analysis: the presence of plaques was a significant predictor of overall survival (HR 1.643; 95% CI 1.033 to 2.615; P = 0.036).
  • Clinical stage I patients with emphysema (Goddard score 5 or more points) or interstitial pneumonia: 5-year overall survival was 49.5% (95% CI 34.5% to 64.6%) with plaques versus 66.3% (95% CI 56.2% to 75.1%) without (P less than 0.001).
  • No patient in the cohort developed malignant pleural mesothelioma after surgery for lung cancer.
• The authors' conclusion: The authors concluded that resected non-small cell lung cancer patients with pleural plaques seen during surgery had a significantly worse prognosis. In their view, careful follow-up after resection is needed because these patients tend to have more invasive lung cancer and to die from respiratory disease.
• Limitations the authors state:
  • Single-institution, retrospective design.
  • No information on individual asbestos exposure, so no analysis by exposure history was possible.
  • No information on whether plaques were seen on preoperative CT scans.
  • Deaths from causes other than respiratory disease and lung cancer, including other cancers, also appeared higher in the plaque group, for unknown reasons.
  • The presence of plaques was confounded by sex and smoking.
  • Stage and histological type could not be adjusted for with methods such as propensity score matching, because they were among the outcomes.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Prognosis, Non-Small Cell Lung Cancer, Pleural Plaques, Intrathoracic, Lung Cancer, Squamous Cell Carcinoma, Overall Survival, Hazard Ratio.

Related studies

• NTRK and ALK rearrangements in malignant pleural mesothelioma, pulmonary neuroendocrine tumours and non-small cell lung cancer — J.L. Leal, G. Peters, et al. (2020)
• Loss of BRCA1-associated protein 1 (BAP1) expression is rare in non-small cell lung cancer — D. Owen, B.S. Sheffield, et al. (2017)
• Pemetrexed induced acute kidney injury in patients with non-small cell lung cancer: reversible and chronic renal damage — G. Rombolà, F. Vaira, et al. (2015)
• Safety of Same-Day Vitamin B12 Supplementation in Patients Receiving Pemetrexed for the Treatment of Non-Small-Cell Lung Cancer or Pleural Mesothelioma: A Retrospective Analysis — Z. Schlei, W. Tan, et al. (2018)
• miR-1254 and miR-574-5p: serum-based microRNA biomarkers for early-stage non-small cell lung cancer — K.M. Foss, C. Sima, et al. (2011)
• High-intensity statins are associated with improved clinical activity of PD-1 inhibitors in malignant pleural mesothelioma and advanced non-small cell lung cancer patients — L. Cantini, F. Pecci, et al. (2021)

Browse more research in BMC Cancer, or return to medical research.