High-dose chemotherapy with autologous stem cell transplantation (HDC-ASCT) for relapsed metastatic germ cell tumors (mGCTs): The Alberta experience from 2001 to 2018.

Abstract

406 Background: HDC-ASCT is a standard therapy for patients (pts) with mGCTs whose disease progresses on or after conventional dose chemotherapy. We conducted a retrospective review of HDC-ASCT in pts with relapsed mCGT in Alberta over the past two decades. Methods: Pts with mGCTs who received HDC-ASCT at two provincial referral cancer centers in Alberta, Canada from 2001-2018 were identified. Baseline clinical and treatment characteristics were collected as well as overall survival (OS) and disease-free survival (DFS). Relevant prognostic variables were analyzed. Results: Forty three pts were identified. Median age was 28 years (range 19 – 56). Majority (95%) had non-seminoma histology and testis/retroperitoneal primary (84%). Twenty pts (47%) had poor risk disease as per IGCCC at start of first-line chemotherapy. HDC-ASCT was used as second-line therapy in 65% and 58% received tandem HDC-ASCT. Median follow-up from ASCT was 22 months (range 2 – 181). At last follow-up, 42% of pts are alive without disease, including 3/7 (43%) of pts with primary mediastinal disease. Two-year and 5-year DFS/OS were 44%/51% and 41%/43%, respectively. Median OS and DFS for all pts were 27.9 months (10.2 – NR) and 9.3 months (4.2 – 124), respectively. Conclusions: We found that HDC-ASCT is an effective salvage therapy in mGCT, consistent with existing literature. Pts appeared to benefit regardless of primary site. Though limited by small sample size, we found a numerical difference in DFS and OS between 2nd and 3rd line HDC-ASCT and single vs. tandem ASCT.[Table: see text]