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 primarily of single-institution studies with small sample sizes. The objective of this study was to assess the association of survival outcomes with surgery vs nonoperative management for patients with early-stage primary mediastinal germ cell tumors.

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

Results: For 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. For patients with nonseminomatous 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 compared with chemotherapy in unadjusted, multivariable-adjusted, and propensity score-matched analysis.

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