Principles of medical and oncological management of giant masses of the mediastinum: a narrative review

Giant mediastinal tumors are represented by well-defined histological variants originating from different structures and compartments while their clinical presentation may be similar and characterized by the same set of symptoms, the well-known mediastinal syndrome (MS). In 80% of cases the MS is caused by malignant neoplasms, such as lung tumors, in 10-18% of cases by hematological neoplasms and in 2-3% by benign causes. In this review we investigated the medical treatment of main giant mediastinal tumors, focusing our interest on the objective response rate (ORR), as it represents the most suitable parameter to predict the volumetric reduction of the neoplasm and, consequently, the regression of their most severe complication, the MS. We will also cover the supportive and symptomatic treatment of MS. We performed a deep analysis of the recent international literature published on PUBMED, UpToDate and Medline. The literature search was undertaken from origin until November 30th, 2021, and we only considered publications in English. Considering the variety of pathologies that can occur in the mediastinum, a rapid histological characterization of the neoplasm is mandatory. In fact, the treatment of these neoplasms includes different approaches, sometimes used in combination, which include chemotherapy, radiotherapy, and surgery. The vena cava syndrome (VCS), due to its high mortality, is considered an oncological emergency and, therefore, requires effective treatments carried out urgently, evaluated in multidisciplinary meeting. The treatment of MS includes both antiblastic treatments and therapies directed to the symptoms. Among the former, chemotherapy, target therapy, radiation and surgery may be used, according to the etiology of MS. Among the latters, supportive therapies, interventional radiology procedures such as stenting may help manage this syndrome, despite the prognosis is poor in most cases and linked to the histology of the tumor, which therefore represents the most important prognostic factor.