O’Neill AF, Xia C, Krailo MD, et al. - Among 131 patients with germ cell tumors for whom data were retrospectively analyzed from Children's Oncology Group protocol AGCT0132, researchers focused on the link between α-fetoprotein (AFP) decline (tumor marker decline) and outcome. They calculated serum AFP half-life from levels obtained postoperatively as a baseline and following the commencement of chemotherapy. The various classes of AFP decline included automatically satisfactory (AFP normalized within the first 2 AFP measures after the start of chemotherapy), calculated satisfactory (AFP half-life ≤ 7 days after the start of chemotherapy), and unsatisfactory. For patients with a satisfactory decline and for those with an unsatisfactory decline, the estimated 3-year cumulative incidence of relapse was 11% and 38%, respectively. For those with a satisfactory decline vs an unsatisfactory decline, the estimated 3-year overall survival was not statistically significant. In pediatric patients treated for germ cell tumors, a link between AFP decline and the cumulative incidence of relapse was shown for the first time in this study.