Poor Prognostic Factors in Patients with Malignant Pleural Mesothelioma Classified as Pathological Stage IB According to the Eighth Edition TNM Classification

Our plain-English summary of Poor Prognostic Factors in Patients with Malignant Pleural Mesothelioma Classified as Pathological Stage IB According to the Eighth Edition TNM Classification, by T. Takuwa, M. Hashimoto, A. Kuroda, et al (Annals of Surgical Oncology, 2018).

The study

• Authors: T. Takuwa, M. Hashimoto, A. Kuroda, A. Nakamura, T. Nakamichi, A. Fukuda, S. Matsumoto, N. Kondo, S. Hasegawa
• Journal: Annals of Surgical Oncology
• Published: 2018;25(6):1572-1579
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Introduction: The change in TNM classification of malignant pleural mesothelioma (MPM) between the seventh and eighth edition classifications has resulted in the downstaging of many advanced-stage patients into pathological stage IB. Many mesotheliomas without lymph node metastasis have been classified as stage IB in the eighth edition classification. Stage IB mesotheliomas comprised a heterogeneous group with different prognosis. It is necessary to clarify the prognostic factors in this group.

Methods: Between September 2009 and August 2016, a total of 89 patients with MPM underwent curative intent surgery [pleurectomy decortication n = 57 (64.1%), extrapleural pneumonectomy n = 32 (35.9%)] at our institution. Of these, 40 were reclassified as stage IB according to the eighth edition TNM classification. Independent unfavorable prognostic factors were identified by univariate analyses using the log-rank test and Cox proportional hazards regression models.

Results: Three independent significant factors were identified that indicated an unfavorable prognosis: a nonepithelioid subtype, lymphovascular invasion, and preoperative forced expiratory volume in 1 s (FEV1) < 2000 ml. Patients with no, one, and two of these risk factors showed 3-year overall survival probabilities of 94.7, 62.5, and 0%, respectively. The 3-year survival of patients with one factor did not differ significantly from that of patients with stage III MPM, whereas that of patients with two factors was significantly shorter (p = 0.015).

Conclusions: Independent poor prognostic factors for patients with stage IB MPM patients, allowing subgroups with poorer and more favorable prognoses to be identified. This should help personalize decisions on adjuvant chemotherapy.

In plain English

This retrospective review of medical records looked at 89 consecutive patients with malignant pleural mesothelioma treated at Hyogo College of Medicine Hospital in Japan between September 2009 and August 2016. All had chemotherapy (pemetrexed plus cisplatin) before surgery intended to cure. When the patients were restaged under the eighth edition of the TNM staging system, 40 fell into stage IB, including 24 previously classed as stage III. In these 40 patients, 3-year survival was 73.7%, and survival did not differ significantly from that of stage IA or stage III patients. Three factors were independently linked to shorter survival: a nonepithelioid tumor type, tumor cells inside lymph or blood vessels (lymphovascular invasion), and a pre-surgery lung function measure (FEV1) below 2000 ml. Three-year survival was 94.7% for stage IB patients with none of these factors, 62.5% with one, and 0% with two. The two-factor group had only 3 patients. The authors concluded that these factors can help personalize treatment after surgery. The article did not discuss asbestos exposure, and some of its figures are inconsistent with one another.

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 review of medical records from a prospectively registered database at a single institution (prognostic factor analysis)
• Who was studied: 89 consecutive patients with malignant pleural mesothelioma (stages IA to IV by the seventh edition TNM classification) who underwent macroscopic complete resection with curative intent at Hyogo College of Medicine Hospital, Nishinomiya, Japan, September 2009 to August 2016. The main analysis covered the 40 patients reclassified as stage IB under the eighth edition.
• Exposure: Asbestos exposure was not studied or mentioned. The study examined clinical and pathological factors in relation to survival. All patients received three courses of pemetrexed plus cisplatin before surgery. Surgery was pleurectomy and decortication in 57 cases (64.1%) and extrapleural pneumonectomy in 32 cases (35.9%).
• Main results:
  • Under the eighth edition classification, 40 of the 89 patients were stage IB: 16 with T2 tumors formerly stage II and 24 with T3 tumors formerly stage III.
  • By eighth edition stage, 3-year overall survival was 84.7% (IA), 73.7% (IB), 0% (II) and 44.9% (III). Stage IB survival did not differ significantly from stage IA (p = 0.104) or stage III (p = 0.097).
  • In multivariate analysis of the stage IB patients, nonepithelioid histologic type was an independent factor for poor prognosis: hazard ratio 30.223 (95% CI 2.641 to 345.85), p = 0.006.
  • In the same analysis of stage IB patients, presence of lymphovascular invasion had a hazard ratio of 9.716 (95% CI 1.648 to 57.264), p = 0.012.
  • In the same analysis of stage IB patients, preoperative FEV1 below 2000 ml had a hazard ratio of 6.593 (95% CI 1.121 to 38.787), p = 0.037.
  • Stage IB patients were scored by number of risk factors (score 0 n = 20, score 1 n = 17, score 2 n = 3; no patient had all three). Three-year overall survival was 94.7%, 62.5% and 0% for scores 0, 1 and 2, and 5-year overall survival was 60.9%, 0% and 0%. Median survival was 38.1 months (score 1) and 12.1 months (score 2) and was not reached for score 0.
  • Survival of stage IB patients with score 0 did not differ significantly from stage IA patients (p = 0.886).
  • Survival of stage IB patients with score 1 did not differ significantly from stage III patients (p = 0.712).
  • Stage IB patients with score 2 had significantly shorter survival than stage III patients (p = 0.015).
• The authors' conclusion: The authors concluded that nonepithelioid subtype, lymphovascular invasion and preoperative FEV1 below 2000 ml are independent poor prognostic factors for patients with malignant pleural mesothelioma classified as stage IB under the eighth edition TNM classification. In their view, these factors allow poorer and more favorable subgroups to be identified, which can help personalize postoperative treatment.

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, TNM Classification, Mesothelioma, Metastasis, Prognosis, Extrapleural Pneumonectomy (EPP), FEV1, Overall Survival.

Related studies

• The IASLC Mesothelioma Staging Project: Proposals for the M Descriptors and for Revision of the TNM Stage Groupings in the Forthcoming (Eighth) Edition of the TNM Classification for Mesothelioma — V.W. Rusch, K. Chansky, et al. (2016)
• The IASLC Mesothelioma Staging Project: Proposals for Revisions of the N Descriptors in the Forthcoming Eighth Edition of the TNM Classification for Pleural Mesothelioma — D. Rice, K. Chansky, et al. (2016)
• Low calretinin expression and high neutrophil-to-lymphocyte ratio are poor prognostic factors in patients with malignant mesothelioma undergoing extrapleural pneumonectomy — S.C. Kao, S. Klebe, et al. (2011)
• Extrapleural pneumonectomy for malignant pleural mesothelioma: outcomes of treatment and prognostic factors — T.D. Yan, M. Boyer, et al. (2009)
• Importance of excision repair cross-complementation group 1 and ribonucleotide reductase M1 as prognostic biomarkers in malignant pleural mesothelioma treated with platinum-based induction chemotherapy followed by surgery — L. Frischknecht, M. Meerang, et al. (2015)
• Factors predicting poor survival after lung-sparing radical pleurectomy of IMIG stage III malignant pleural mesothelioma — S. Bölükbas, M. Eberlein, et al. (2013)

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