Optimal Treatment Strategies for Early-Stage Primary Mediastinal Germ Cell Tumors.

Background: Data on optimal therapy for patients with primary mediastinal germ cell tumors consist overwhelmingly of single-institution studies with small sample sizes. The objective of this study is to assess the association of survival outcomes with surgery vs non-operative management for patients with early-stage primary mediastinal germ cell tumors.

Methods: Overall survival of all patients with seminomas and non-seminomatous primary germ cell tumors in the mediastinum who received 1) chemotherapy, or 2) surgery with or without chemotherapy (referred to as 'surgery' for simplicity) for early-stage disease from 2004-2015 in the National Cancer Database was assessed using Kaplan-Meier analysis, propensity score-matched analysis, and multivariable Cox proportional hazards analysis.

Results: Among patients with seminomas, chemotherapy alone was used in 120 (80.5%) patients and surgery was used in 29 (19.5%) patients. There was no significant difference in 5-year survival between surgery and chemotherapy in unadjusted and propensity score-matched analysis. Among patients with non-seminomatous tumors, chemotherapy alone was used in 91 (46.7%) patients and surgery was used in 104 (53.3%) patients. Surgery was associated with improved 5-year survival when compared to chemotherapy in unadjusted, and multivariable-adjusted, and propensity score-matched analysis.

Conclusions: In this national analysis, multimodality treatment involving surgery was associated with improved survival when compared to chemotherapy alone for early-stage primary mediastinal non-seminomatous germ cell tumors. For seminomas of the mediastinum, chemotherapy was associated with similar long-term outcomes when compared to multimodality treatment involving surgery.