Malignant pleural mesothelioma: The disdained member of thoracic oncology!

Abstract

Pleural mesothelioma is a very aggressive malignancy that arises from the pleural mesothelial cell lining and is linked strongly to prior asbestos exposure. The ban on asbestos has helped to lower the incidence, but in developing countries like India, it is expected to rise. It has an extended latency period usually progressing over decades and presents with nonspecific symptoms. It has a median survival ranging between 10-22 months. The diagnosis of malignant pleural mesothelioma is challenging and is done using computed tomography (CT), magnetic resonance imaging, or positron emission tomography-CT, with the last two predicting the resectability of the tumor better than CT alone. A pleural biopsy along with an array of immunohistochemical markers, such as p16, BRCA1 associated protein 1, and claudin-4, are required for a definitive diagnosis. Several genetic alterations have prognostic significance as well. The current histological subtype identification is indispensable for decision making because of the new therapeutic avenues being explored. The combination of nivolumab and ipilimumab-based immunotherapy outperformed platinum and pemetrexed-based chemotherapy in terms of survival benefit and improved quality of life especially for non-epithelioid subtypes. However, the latter continues to be a robust treatment option for patients with the epithelioid subtype. Surgery is recommended for resectable cases with radiotherapy being indicated in neoadjuvant, adjuvant, and palliative settings along with systemic treatment. This review article provides an overview of epidemiology, etiology, clinical manifestations, diagnostic approaches (including immunohistochemical and genetic markers), staging, and multidisciplinary approaches to current treatment for malignant pleural mesothelioma using surgery, chemotherapy, immunotherapy, and radiotherapy. It also sheds light on some recent studies (EMPHACIS, CALGB30901, Checkmate-743, etc.) that have led to significant developments in recent years with clinically meaningful results.