Risk factors, prognostic factors, and nomograms for distant metastasis in patients with malignant pleural mesothelioma: A population-based retrospective study

ObjectivesMalignant pleural mesothelioma is a rare and aggressive thoracic tumor with a poor prognosis, wherein distant metastasis is associated with the lowest survival rates. It is imperative and emergent to construct nomograms based on risk factors and prognostic factors for distant metastasis in patients with malignant pleural mesothelioma.MethodsWe extracted data for the duration between 2010 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database and randomly categorized the patients into the training (70%) and validation (30%) cohorts. Risk factors for distant metastasis in patients with malignant pleural mesothelioma were identified using univariate and multivariate logistic regression analyses, and prognostic factors for patients with distant metastasis were determined using univariate and multivariate Cox regression analyses. Two nomograms were established based on the training cohort and evaluated using the validation cohort. The C-index, receiver operating characteristic curve, calibration curve, and decision curve analysis were used to assess the performance of the two nomograms.ResultsIn total, 2056 primary malignant pleural mesothelioma patients were included, and 341 patients were initially diagnosed with metastatic malignant pleural mesothelioma. Histology, laterality, grade, tumor stage, and node stage were independent risk factors for distant metastasis in patients with malignant pleural mesothelioma. Chemotherapy and metastasis to the lung, bone, and brain were independent prognostic factors for patients with malignant pleural mesothelioma and distant metastasis. The C-index values of the risk nomogram in the training and validation cohorts were 0.723 and 0.782, respectively. The C-index values of the prognostic nomogram in the training and validation cohorts were 0.678 and 0.712, respectively. The receiver operating characteristic curves, calibration curves, and decision curve analysis also demonstrated good predictive performance for the two nomograms in the training and validation cohorts.ConclusionsNomograms are useful and reliable tools for predicting distant metastatic risk in patients with malignant pleural mesothelioma and overall survival in patients with malignant pleural mesothelioma who had distant metastasis. These nomograms can provide strong references to clinicians to facilitate clinical decisions.