Salvage high-dose chemotherapy for primary mediastinal nonseminomatous germ cell tumors: Single institute experience.

Abstract

e15503 Background: Primary mediastinal non-seminomatous germ cell tumors (PMNSGCT) bear a worse prognosis than stage-matched testicular primaries, with a five year survival rate of 50%. In contrast to relapsed testicular NSGCT, retrospective analyses have not shown benefit to high-dose chemotherapy and autologous stem-cell transplant (HDCT/ ASCT) in PMNSGCT patients. Since publication of these studies, advancements in treatment regimens and supportive care have occurred, with emerging evidence suggesting HDCT/ASCT may benefit patients with PMNSGCT - both as first-line sequential treatment after standard-dose chemotherapy and at relapse. Objectives: Review the experience of patients presenting with PMNSGCT to a regional referral cancer center as a quality control assessment. Assess the benefit of salvage HDCT/ASCT to relapsed PMNSGCT patients. Methods: Patients presenting with PMNSGCT from 1980-2010 were abstracted from a Provincial cancer registry and records were retrospectively reviewed. Data includes patient demographics, cancer treatments and outcomes. Results: Fourteen male patients (median age 29; range: 17-54 years) with PMNSGCT were identified. Seven of 13 (54%) patients remain continuously disease-free with 1 patient lost to follow-up. Mean duration of follow-up in these patients is 57 (34-100) months. Three patients died having received ≤ 1 cycle of chemotherapy; exclusion of these patients results in a treatment failure rate of 30%. Six of the 7 cancer-free patients required salvage surgery. Three patients received tandem HDCT/ASCT (carboplatin 550 mg/m2 and etoposide 150 mg/m2daily for 4 days) at subsequent relapse despite second-line chemotherapy. Two remain disease-free at 45 and 74 months respectively, while the third patient died of their disease 14 months post-transplant. Conclusions: Our experience with PMNSGCT is generally consistent with published outcomes in that ≈50% of patients are cured. However, in this series 2/3 heavily pretreated patients were salvaged with HDCT/ASCT, refuting the published historical experience. This study is limited by its small sample size, but provides impetus to re-examine HDCT/ASCT for high-risk patients.