Acute changes of alpha-fetoprotein and human chorionic gonadotropin during induction chemotherapy of germ cell tumors.

Thirty-seven consecutive patients with germ cell cancers (34 testicular, three extragonadal) and elevated serum levels of alpha-fetoprotein (AFP) and/or human chorionic gonadotropin (HCG) were treated with vinblastine, bleomycin, and cis-diamminedichloroplatinum induction chemotherapy. The AFP and/or HCG normalized in 36 patients. The AFP half-life was 7.9 days between Days 1 and 21 postchemotherapy but 6.0 days between Days 21 and 42 (p less than 0.05). The prolonged AFP half-life between Days 1 and 21 was related to a median increase of 57.5% (range, 22 to 219%) in the AFP level. This increase in the marker value occurred between Days 2 and 9 of therapy (median, Day 5). There was also a median increase of 181% (range, 27 to 600%) in the HCG level at a median of 5 days after the start of therapy. The increase in the AFP and HCG levels occurred in 63 and 70% of evaluable patients, respectively, and correlated with the presence of a large volume of metastatic disease (chi 2 = 8.87). Patients with relapsed or refractory disease had prolongation of the AFP half-life between Days 21 and 42 as compared to nonrelapsed patients. AFP and HCG half-life calculations should be used in the management of patients with germ cell cancers.