Clinicopathologic predictors of outcomes in children with stage I testicular germ cell tumors: A pooled post hoc analysis of trials from the Children's Oncology Group.

BACKGROUND: Patients with clinical stage I (CS I: cN0M0) testicular germ cell tumors (TGCT) exhibit favorable oncologic outcomes. While prognostic features can help inform treatment in adults with CS I TGCT, we lack reliable means to predict relapse among pediatric and adolescent patients. OBJECTIVE: We sought to identify predictors of relapse in children with CS I TGCT. STUDY DESIGN: We performed a pooled post hoc analysis on pediatric and adolescent AJCC CS I TGCT patients enrolled in 3 prospective trials: INT-0097 (phase II), INT-0106 (phase III), and AGCT0132 (phase III). Pathology was centrally reviewed. Patient demographics, pT stage, serum tumor markers, margin status, histology, relapse, and survival were compiled. Cox regression analyses were used to identify predictors of events, defined as relapse, secondary malignant neoplasm, or death. RESULTS: 106 patients were identified with outcomes data available. Most patients were pT1-2 stage. Among patients with evaluable histopathology, yolk sac tumor elements were present in all patients and lymphovascular invasion in 51% of patients. Over a median follow-up of 56 months, no patients died, and 25 patients (24%) experienced an event (median event-free survival not reached). Independent predictors of events on multivariable analysis included age ≥12 years at diagnosis (HR 8.87, p < 0.001) and higher pT stage (pT2 HR 7.31, p = 0.0017; pT3 HR 13.5, p = 0.0043). DISCUSSION: Although our study population reflects the largest pooled prospective cohort of CS I pediatric and adolescent TGCT to our knowledge, the relatively low event rate limits our multivariable analysis, and longer follow-up duration would help further characterize the natural history of these patients. Centralized pathologic review was also unable to be performed for several patients. CONCLUSION: Pediatric and adolescent CS I TGCT patients exhibit remarkable 5-year survival. Using combined data from multiple prospective trials, our study identifies clinicopathologic features that predict relapse and inform personalized treatment for these patients by potentially guiding surveillance versus adjuvant treatment strategies.

Effect of chronic perinatal hypoxia on the role of rho-kinase in pulmonary artery contraction in newborn lambs.

Exposure to chronic hypoxia during gestation predisposes infants to neonatal pulmonary hypertension, but the underlying mechanisms remain unclear. Here, we test the hypothesis that moderate continuous hypoxia during gestation causes changes in the rho-kinase pathway that persist in the newborn period, altering vessel tone and responsiveness. Lambs kept at 3,801 m above sea level during gestation and the first 2 wk of life were compared with those with gestation at low altitude. In vitro studies of isolated pulmonary arterial rings found a more forceful contraction in response to KCl and 5-HT in high-altitude compared with low-altitude lambs. There was no difference between the effects of blockers of various pathways of extracellular Ca(2+) entry in low- and high-altitude arteries. In contrast, inhibition of rho-kinase resulted in significantly greater attenuation of 5-HT constriction in high-altitude compared with low-altitude arteries. High-altitude lambs had higher baseline pulmonary artery pressures and greater elevations in pulmonary artery pressure during 15 min of acute hypoxia compared with low-altitude lambs. Despite evidence for an increased role for rho-kinase in high-altitude arteries, in vivo studies found no significant difference between the effects of rho-kinase inhibition on hypoxic pulmonary vasoconstriction in intact high-altitude and low-altitude lambs. We conclude that chronic hypoxia in utero results in increased vasopressor response to both acute hypoxia and serotonin, but that rho-kinase is involved only in the increased response to serotonin.

Maternal caffeine administration and cerebral oxygenation in near-term fetal sheep.

The authors test the null hypothesis that maternal caffeine administration will not significantly alter fetal cerebral oxygenation. The authors measured fetal arterial blood gases, cortical tissue O(2) tension (tPO(2)), sagittal sinus blood gases, and laser Doppler cerebral blood flow in response to a 30-minute caffeine infusion (400 mg intravenously) into 7 near-term pregnant ewes, and they calculated fractional O(2) extraction and relative cerebral metabolic rate for O(2) (CMRO(2)). Following maternal caffeine infusion, both fetal cortical tPO(2) and sagittal sinus (HbO(2)) decreased significantly, from 10.7 +/- 0.9 to 6.8 +/- 1.1 Torr and from 46% +/- 2% to 37% +/- 6%, respectively. This was associated with significant 20% to 30% increases in fractional O(2) extraction and CMRO( 2). Fetal arterial blood gas values did not change significantly. In conclusion, maternal caffeine administration significantly decreases cerebral oxygenation without affecting systemic oxygenation in fetal sheep. The authors speculate that for a fetus that may be otherwise compromised, this increase in CMRO(2) with decreased cortical tPO(2) could present a problem.