Tumor marker kinetics predict outcome in patients with relapsed disseminated non-seminomatous germ-cell tumors

Background: An early serum tumor marker (TM) decline during chemotherapy was shown to independently predict survival in patients with poor-prognosis disseminated non-seminomatous germ-cell tumors (NSGCTs). The aim of this study was to assess whether a TM decline (TMD) also correlates with the outcome in the salvage setting. Patients and methods: Data regarding 400 patients with progressive or relapsed disseminated NSGCTs after firstline chemotherapy prospectively accrued onto two phase III clinical trials were obtained. Serum alpha-fetoprotein (AFP) and/or human chorionic gonadotropin (hCG) were assessed at baseline and after 6 weeks of chemotherapy. A total of 297 patients, 185 and 112 in the training and validation sets, with initially abnormal TMs for whom a change from baseline could be established were used for this analysis. Results: An unfavorable decline in either AFP or hCG was predictive of progression-free survival (PFS) [hazard ratio, HR = 2.15, (95% CI 1.48-3.11); P < 0.001; 2-year PFS rate: 50% versus 26%] as was the Lorch prognostic score (LPS). In the multivariate analysis, an unfavorable TMD, stratified based on the LPS, was an independent adverse prognostic factor for PFS and OS. Conclusion: An unfavorable TMD during the first 6 weeks after chemotherapy is associated with a poorer outcome in patients with relapsed disseminated NSGCTs.