The concept of therapy selection being guided by prognostic factors has been proven successful in first-line therapy and is now also being implemented in salvage therapy [10, 18]. However, the process of identifying prognostic factors in patients with relapsed and refractory tumors is being rendered more difficult by the fact that the data available are far more heterogeneous. While a range of prognostic factors have been known for some years, their wider acceptance and the introduction of a validated prognostic score have been rather recent developments (Table 7.2).

Two years ago, an article was published that reported on the retrospective analysis of data collected on nearly 1,600 patients worldwide who presented with relapsed or refractory disease and who had received either CDCT or HDCT as initial salvage therapy. The research was able to identify seven independent variables with a significant impact on progression-free survival (PFS) and overall survival (OS) as well as being successful in developing a prognostic scoring system. A total of five prognostic categories were defined based on these variables. The 2-year PFS, estimated using the Kaplan-Meier method, was 75 % for patients in the very-low-risk group, 51 % for patients in the low-risk group, 40 % for patients in the intermediate-risk group, 26 % for patients in the high-risk group, and 6 % for patients in the very-high-risk group [1]. Patients with pure seminoma represented a separate subgroup among the five prognostic categories.