Immunohistochemical analysis of H3K27me3 demonstrates global reduction in group-A childhood posterior fossa ependymoma and is a powerful predictor of outcome.

Posterior fossa ependymomas (EPN_PF) in children comprise two morphologically identical, but biologically distinct tumor entities. Group-A (EPN_PFA) tumors have a poor prognosis and require intensive therapy. In contrast, group-B tumors (EPN_PFB) exhibit excellent prognosis and the current consensus opinion recommends future clinical trials to test the possibility of treatment de-escalation in these patients. Therefore, distinguishing these two tumor subtypes is critical. EPN_PFA and EPN_PFB can be distinguished based on DNA methylation signatures, but these assays are not routinely available. We have previously shown that a subset of poorly prognostic childhood EPN_PF exhibits global reduction in H3K27me3. Therefore, we set out to determine whether a simple immunohistochemical assay for H3K27me3 could be used to segregate EPN_PFA from EPN_PFB tumors. We assembled a cohort of 230 childhood ependymomas and H3K27me3 immunohistochemistry was assessed as positive or negative in a blinded manner. H3K27me3 staining results were compared with DNA methylation-based subgroup information available in 112 samples [EPN_PFA (n = 72) and EPN_PFB tumors (n = 40)]. H3K27me3 staining was globally reduced in EPN_PFA tumors and immunohistochemistry showed 99% sensitivity and 100% specificity in segregating EPN_PFA from EPN_PFB tumors. Moreover, H3K27me3 immunostaining was sufficient to delineate patients with worse prognosis in two independent, non-overlapping cohorts (n = 133 and n = 97). In conclusion, immunohistochemical evaluation of H3K27me3 global reduction is an economic, easily available and readily adaptable method for defining high-risk EPN_PFA from low-risk posterior fossa EPN_PFB tumors to inform prognosis and to enable the design of future clinical trials.

The NOFLO trial: low-flow nasal prongs therapy in weaning nasal continuous positive airway pressure in preterm infants.

OBJECTIVE: To determine if low-flow nasal prongs therapy with room air, compared with no treatment, facilitates weaning from nasal continuous positive airway pressure (NCPAP) in very low birth weight (VLBW, birth weight <1500 g) infants. STUDY DESIGN: VLBW infants who received respiratory support for ≥ 48 hours and who were stable on NCPAP for 24 hours were eligible for inclusion in this multicenter, randomized controlled trial. On stopping NCPAP, infants were randomized to receive 1 L/min air via nasal prongs or to spontaneous breathing in room air. The primary outcome measure was failure to wean. Secondary outcome measures included length of time to failure and change in heart rate, respiratory rate, oxygen saturation, and respiratory distress score. RESULTS: Seventy-eight infants were randomized: 39 to nasal prongs and 39 to spontaneous breathing. The groups were similar at birth and at randomization. Sixteen infants (41%) in the nasal prongs group failed the weaning process compared with 12 infants (31%) in the spontaneous breathing group (OR 1.57, 95% CI 0.56 to 4.43, P = .48). There were no significant differences between the groups in secondary outcomes. CONCLUSIONS: In this study, we did not demonstrate a benefit of low-flow room air via nasal prongs to wean VLBW infants from NCPAP.