Computed tomography in the evaluation of malignant pleural mesothelioma—Association of tumor size to a sarcomatoid histology, a more advanced TNM stage and poor survival

• Published in: Lung cancer (Amsterdam, Netherlands) Netherlands), 2018-02, Vol.116, p.73-79
• Main Authors: Paajanen, Juuso, Laaksonen, Sanna, Ilonen, Ilkka, Wolff, Henrik, Husgafvel-Pursiainen, Kirsti, Kuosma, Eeva, Ollila, Hely, Myllärniemi, Marjukka, Vehmas, Tapio
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Computed tomography; Female; Humans; Lung Neoplasms - diagnostic imaging; Lung Neoplasms - pathology; Male; Mesothelioma; Mesothelioma - diagnostic imaging; Mesothelioma - pathology; Mesothelioma, Malignant; Middle Aged; Neoplasm Staging; Pleural Neoplasms - diagnostic imaging; Pleural Neoplasms - pathology; Prognosis; Retrospective Studies; Staging; Tomography, X-Ray Computed; Tumor size
• ISSN: 0169-5002; 1872-8332
• DOI: 10.1016/j.lungcan.2018.01.001

•A novel computed tomography based tumor size evaluation for MPM is proposed.•Tumor size was estimated by using tumor thickness and chest wall extension.•Tumor size was associated with TNM stage, sarcomatoid histology and mortality.•Pleural effusion and non-epithelioid histology were also predictors of poor outcome. Appropriate clinical staging of malignant pleural mesothelioma (MPM) is critical for correct treatment decisions. Newly revised TNM staging protocol has been released for MPM. We investigated baseline computed tomography (CT) characteristics of MPM patients, the new staging system and a simple tumor size (TS) assessment in terms of survival. As part of our study that included all MPM patients diagnosed in Finland 2000–2012, we retrospectively reviewed 161 CT scans of MPM patients diagnosed between 2007 and 2012 in the Hospital District of Helsinki and Uusimaa. TS was estimated by using the maximal tumor thickness and grading tumor extension along the chest wall. Cox Regression models were used to identify relationships between survival, clinicopathological factors and CT-findings. The median length of follow-up was 9.7 months and the median survival 9.1 months. The right sided tumors tended to be more advanced at baseline and had worse prognosis in the univariate analyses. In the multivariate survival model, TS, pleural effusion along with non-epithelioid histology were predictors of poor survival. Tumor size correlated significantly with a sarcomatoid histopathological finding and several parameters linked to a more advanced TNM stage. Most patients were diagnosed with locally advanced stage, while 12 (7%) had no sign of the tumor in CT. In this study, we demonstrate a novel approach for MPM tumor size evaluation that has a strong relationship with mortality, sarcomatoid histology and TNM stage groups. TS could be used for prognostic purposes and it may be a useful method for assessing therapy responses.