Primary Mediastinal Germ Cell Tumors (PMGCT): A Real-world Analysis From A Tertiary Cancer Care Center in India.

Background: Primary mediastinal GCT (PMGCT) is a rare entity and comprises 10-15% of all mediastinal tumors. We present our institutional experience of MGCT treated with multimodality management.

Materials And Methods: We conducted a retrospective analysis between 2010 to 2020 of all mediastinal germ cell tumors registered at our center. Data on patient demographics, treatments received, treatment toxicities and response were recorded. Overall survival and relapse free survival were estimated using Kaplan-Meier methods.

Results: A total of 30 patients were identified. The median age was 25.5 (range, 18-45) years. Common presenting features included cough (70%) and shortness of breath (70%). Histology wise, 60% patients were non seminomatous histology, whereas 33.3% patients were Seminoma. Twenty-seven (90%) patients received chemotherapy as the first-line treatment, of whom five patients (16.6%) underwent surgery and radiation therapy subsequently. Median follow-up was 26.9 months. Thirteen patients (43.3%) had complete response (43.3%) and eight patients had partial response (26.7%), while three patients (5.5%) had progressive disease. Three-year relapse-free survival rate was 69.6% (95% confidence interval [CI], 42.8-85.6%). Overall survival (OS) at 3 years was 73.4% (95% CI, 49.4-87.3%). Patients with seminoma had a 3 year OS of 90.0% (95% CI, 47.3-98.5%) compared to those with non-seminoma (63.53% [95% CI, 32.3-83.3%]).

Conclusions: Multiagent chemotherapy is the backbone of treatment in PMGCT. Seminomatous PMGCT have excellent prognosis, while further improvement is needed in those with nonseminomatous tumor.