High-dose chemotherapy for relapsed germ cell tumours: outcomes in low-volume specialized centres.

To report treatment patterns and survival outcomes of patients with relapsed and refractory metastatic germ cell tumours (GCTs) treated with high-dose chemotherapy (HDCT) and autologous stem-cell transplantation in low-volume specialized centres within the widely dispersed populations of Australia and New Zealand between 1999 and 2019.

We conducted a retrospective analysis of 111 patients across 13 institutions. Patients were identified from the Australasian Bone Marrow Transplant Recipient Registry. We reviewed treatment regimens, survival outcomes, deliverability and toxicities. Primary endpoints included overall (OS) and progression-free survival (PFS). Cox proportional hazards models were used to test the association of survival outcomes with patient and treatment factors.

The median (range) age was 30 (14-68) years and GCT histology was non-seminomatous in 84% of patients. International Prognostic Factors Study Group (IPFSG) prognostic risk category was very low/low, intermediate, high and very high in 18%, 36%, 25% and 21% of patients, respectively. Salvage conventional-dose chemotherapy (CDCT) was administered prior to HDCT in 59% of patients. Regimens included paclitaxel, ifosfamide, carboplatin and etoposide (50%), carboplatin and etoposide (CE; 28%), carboplatin, etoposide and ifosfamide (CEI; 6%), carboplatin, etoposide and cyclophosphamide (CEC; 5%), CEC-paclitaxel (6%) and other (5%). With a median follow-up of 4.4 years, the 1-, 2- and 5-year PFS rates were 62%, 57% and 52%, respectively, and OS rates were 73%, 65% and 61%, respectively. There were five treatment-related deaths. Progression on treatment occurred in 17%. In a univariable analysis, worse International Germ Cell Cancer Collaborative Group (IGCCCG) and IPFSG prognostic groups were associated with inferior survival outcomes. An association of inferior survival was not found with the number of high-dose cycles received nor when HDCT was delivered after salvage CDCT.

This large dual-national registry-based study reinforces the efficacy and deliverability of HDCT for relapsed and refractory metastatic GCT in low-volume specialized centres in Australia and New Zealand, with survival outcomes comparable to those found in international practice.

BJU international. 2022 Mar 31 [Epub ahead of print]

Elizabeth A Connolly, Andrew Weickhardt, Peter Grimison, Rebecca Asher, Gillian Z Heller, Jeremy Lewin, Elizabeth Liow, Guy Toner, Iris L Y Tung, Ben Tran, Sean Hill, Euan Walpole, Jane McKenzie, Anna Kuchel, Jeffrey Goh, Garry Forgeson, Alvin Tan, Abhishek Joshi, Alistair Wickham, Hsiang Tan, Yang Wang, Mark A Winstanley, Nada Hamad, Vanessa Wong

Chris O Brien Lifehouse, Sydney, Australia., Olivia Newton-John Cancer and Wellness Centre Austin Health, Melbourne, Australia., NHMRC Clinical Trials Centre, Sydney, Sydney, Australia., University of Sydney, Sydney, Australia., Peter MacCallum Cancer Centre, Melbourne, Australia., Princess Alexandra Hospital, Brisbane, Australia., Royal Brisbane and Women's Hospital and School of Medicine, University of Queensland, Brisbane, Australia., Palmerston North Hospital, Palmerston North, New Zealand., Waikato Hospital, Hamilton, New Zealand., Townsville University Hospital, James Cook University, Townsville, Australia., Auckland City Hospital, Auckland, New Zealand., Royal Adelaide Hospital, Adelaide, Australia., St Vincent's Hospital, Melbourne, Australia., Starship Children's Hospital, Auckland, New Zealand., Australasian Bone Marrow Transplant Recipient Registry (ABMTRR), Sydney, Australia.