High Dose Chemotherapy with Autologous Stem Cell Transplant in Treatment of Germ Cell Tumors: A Systematic Review and Meta-Analysis

Background:

Cure rates for the poor risk, relapsed and refractory germ cell tumors are only 25 % with conventional dose chemotherapy. High Dose Chemotherapy (HDCT) followed by rescue stem cell transplant has since been studied in randomized controlled trails for the IGCCG poor risk group patients and for the relapsed and refractory testicular cancer patients. We conducted a meta-analysis of all prospective Phase II and III trials studying the role of high dose chemotherapy in germ cell tumors.

Methods:

Literature search was conducted using methods described in the PRISMA statement. Medline (PubMed and Ovid SP), Embase, Cochrane Central Register of Controlled Clinical Trials(CENTRAL) and Cochrane Database of Systematic Review (CDSR) were searched from the inception of these databases till present. We performed a meta-analysis using Comprehensive Meta-analysis 3.0 using random effects model. The heterogeneity was assessed using I²values and sensitivity analysis was performed to explain the heterogeneity where present.

Results:

After a comprehensive literature search 4440 studies were identified and finally 35 studies were included in the final analysis. 14 studies involving 905 patients with IGCCG poor risk germ cell cancer were treated with high dose chemotherapy. 44 % (398) patients were able to achieve CR with HDCT with HR of o.48 (0.33-0.62) p=0.75. The overall survival (OS) and Progression free survival (PFS ) were 0.62 (0.54-0.69, p=0.004) and 0.60 (0.52-0.68 p=0.011) respectively.

21 studies involving 1153 patients with relapsed and or refractory germ cell cancer were identified. CR rate with HDCT was 32 % (374 patients) with HR of 0.32 (0.26-0.40, p=0.00). The results for OS failed to show any significant results with HR of 0.52 (0.44-0.60, p=0.67) but was significant for PFS with HR of 0.60 (0.52-0.67, p=0.01).

Conclusion:

High dose chemotherapy followed by HSCT showed significant OS and PFS for IGCCG poor risk category germ cell tumors and significant CR and PFS for relapsed and or refractory germ cell cancer group.