Clinicopathological Features and Prognosis of Primary Mediastinal Malignant Germ Cell Tumors: A Retrospective Single-Institution Analysis

BACKGROUND: Given the lack of evidence-supported guidance for therapeutic recommendations of primary mediastinal malignant germ cell tumors (PMMGCTs), our study aimed to investigate the clinicopathological features, treatment strategies, and prognostic factors of PMMGCTs. METHODS: We carried out a consecutive retrospective evaluation on a series of patients diagnosed with PMMGCTs in Peking Union Medical College Hospital from January 2000 to August 2020. RESULTS: A total of 58 patients were eligible, consisting of 51 males and seven females. There were 15 patients with seminomas, 39 with nonseminomatous germ cell tumors (NSGCTs), and four with mixed germ cell tumors (GCTs). The 5-year overall survival was 45%, with a median survival time of 32.37 months. Except for the lost follow-up of seven patients, a univariate analysis of overall survival on the remaining patients showed significant differences in pathological type (mixed GCTs were regarded as NSGCTs) (p=0.036), tumor size (>11cm) (p=0.006), and other sites metastases (OSM) (p=0.001), respectively. Multivariate Cox regression analysis revealed that OSM and surgical resection were independently associated with overall survival in all kinds of PMMGCTs. CONCLUSION: OSM was an independent risk factor for patients with PMMGCTs. Surgery was proved to contribute to long-term survival. More in-depth clinical evidence is urgently needed to guide the treatment of PMMGCTs.