Survival Outcomes of Patients With Mediastinal Germ Cell Tumors: Experience of a Cancer Center in South America

PurposeMediastinal germ cell tumors (GCT) are rare neoplasms associated with poor survival prognosis. Due to their low incidence, limited information is available about this disease in South America. The objective of this study is to report the clinical characteristics and outcomes of patients with mediastinal GCT in a cancer center in Colombia.Materials and MethodsWe conducted a retrospective analysis of patients with mediastinal GCT treated at the National Cancer Institute at Bogota (Colombia) between 2008 and 2020. Survival curves were presented using the Kaplan–Meier method. Chi-square and Cox proportional hazard model tests were used for data analysis.ResultsSixty-one patients were included in the study. Of them, 60 were male and 51 (83.6%) of whom had non-seminomatous germ cell tumors (NSGCT). Twenty-nine patients (47.5%) presented with superior vena cava syndrome, and 18 (29.5%) patients had extrapulmonary metastatic involvement. The three-year overall survival (OS) of NSGCT patients was 26%. The 3-year OS of NSGCT patients who underwent surgical resection of residual mediastinal mass after chemotherapy was 59%. Non-surgical management after first-line chemotherapy was associated with a worse survival prognosis in NSGCT patients (p = 0.002). Ten patients with mediastinal seminomatous germ cell tumors (SCGT) achieved a 3-year OS of 100%.ConclusionMediastinal NSGCT had poor outcomes. Surgery of the residual mass after first-line chemotherapy seems to improve the outcome of NSGCT patients. Advanced disease at presentation may reflect inadequate access to reference cancer centers in Colombia and potentially explain poor survival outcomes in this cohort. On the other hand, mediastinal SCGT is a biologically different disease; most patients will achieve disease remission and long-term survival with first-line chemotherapy.

Primary Mediastinal and Testicular Germ Cell Tumors in Adolescents and Adults: A Comparison of Genomic Alterations and Clinical Implications

Mediastinal germ cell tumors (MGCTs) share histologic, molecular and biomarkers features with testicular GCTs; however, nonseminomatous MGCTs are usually more aggressive and have poorer prognosis than nonseminomatous TGCTs. Most nonseminomatous MGCT cases show early resistance to platinum-based therapies and seldom have been associated with the onset of one or more concomitant somatic malignancies, in particular myeloid neoplasms with recent findings supporting a common, shared genetic precursor with the primary MGCT. Genomic, transcriptomic and epigenetic features of testicular GCTs have been extensively studied, allowing for the understanding of GCT development and transformation of seminomatous and nonseminomatous histologies. However, MGCTs are still lacking proper multi-omics analysis and only few data are reported in the literature. Understanding of the mechanism involved in the development, in the progression and in their higher resistance to common therapies is still poorly understood. With this review, we aim to collect all molecular findings reported in this rare disease, resuming the similarities and disparities with the gonadal counterparts.