IS SERUM TUMOR-MARKER HALF-LIFE A GUIDE TO PROGNOSIS IN METASTATIC NONSEMINOMATOUS GERM-CELL TUMORS

Background. The value of serum tumor marker kinetics of AFP and HCG as sessed by marker half-life (MHL) analysis for diagnosis and in the fol low-up of patients with nonseminomatous germ cell tumors (NSGCT) is st ill debated controversially. The aim of this retrospective study was t herefore to investigate the influence of serum MHL during the first tw o cycles of chemotherapy on the long-term outcome in metastatic NSGCT. Material and Methods. 147 patients with at least 2 abnormal marker va lues >7 days after start of chemotherapy were investigated for HL anal ysis (HL cut off 3.5 days for HCG and 7 clays for AFP). HCG and AFP de terminations were performed by a double monoclonal IRMA (HCG) and conv entional RIA (AFP) developed by our laboratory. Results. According to these cut offs 35/108 patients (32.4%) had a prolonged HCG HL and 41/1 14 patients (36%) a prolonged AFP HL. Patients with either MHL prolong ed had a significantly inferior overall survival (OS; 10 year OS 37% v s. 75%, p=0.0005) and progression-free survival (PFS; 10 year PFS 29% vs. 69%, p<0.0001) than those with a prolonged HCG MHL (OS; 10 year OS 36% vs. 65%, p=0.003; 10 year PFS 28% vs. 56%; p=0.001) and even more than those with a prolonged AFP MHL (10 year OS 39% vs. 70%, p=0.02; 10 year PFS 32% vs. 56%, p=0.01). Conclusion. The remarkable prognosti c information assessed by MHL analysis in this retrospective study mer its further confirmation by a prospective study for its appropriatenes s in selecting patients for high dose chemotherapy.