Maediastinal germ cell tumors: analysis using hospital-based cancer registry data in Japan.

OBJECTIVES

Mediastinal germ cell tumors are rare and few large-scale studies on mediastinal germ cell tumors are reported. We aimed to investigate the clinical characteristics and survival outcomes of patients with mediastinum germ cell tumors in Japan.

METHODS

A hospital-based cancer registry data in Japan was used to identify and enroll patients diagnosed with mediastinal germ cell tumors in 2012-2013. The datasets were registered from 80 institutions.

RESULTS

The selection criteria were met by 123 patients, the majority of whom were male. The median age at diagnosis was 39 years (range 25-89 years) and the most common age groups at diagnosis was 30-39 years, followed by 40-49 years and ≥ 50 years. The histology of non-seminoma (55.3%) was slightly more frequent than that of seminoma (44.7%). The most common histological subtype in non-seminoma was yolk sac tumor, followed by mixed germ cell tumor. The 5-year survival of seminoma and non-seminoma were 96.4% and 57.3%, respectively (p < 0.001). Non-seminomatous mediastinal germ cell tumors, malignant teratomas, mixed germ cell tumors, and yolk sac tumors had comparable survival rates, while those with choriocarcinoma showed the worst prognosis.

CONCLUSIONS

This is the first report showing the clinical characteristics and survival outcomes of mediastinal germ cell tumors in Japan using a real-world large cohort database.