Multi-institutional study of the frequency, genomic landscape, and outcome of IDH-mutant glioma in pediatrics.

BACKGROUND: The incidence and biology of IDH1/2 mutations in pediatric gliomas are unclear. Notably, current treatment approaches by pediatric and adult providers vary significantly. We describe the frequency and clinical outcomes of IDH1/2-mutant gliomas in pediatrics. METHODS: We performed a multi-institutional analysis of the frequency of pediatric IDH1/2-mutant gliomas, identified by next-generation sequencing (NGS). In parallel, we retrospectively reviewed pediatric IDH1/2-mutant gliomas, analyzing clinico-genomic features, treatment approaches, and outcomes. RESULTS: Incidence: Among 851 patients with pediatric glioma who underwent NGS, we identified 78 with IDH1/2 mutations. Among patients 0-9 and 10-21 years old, 2/378 (0.5%) and 76/473 (16.1%) had IDH1/2-mutant tumors, respectively. Frequency of IDH mutations was similar between low-grade glioma (52/570, 9.1%) and high-grade glioma (25/277, 9.0%). Four tumors were graded as intermediate histologically, with one IDH1 mutation. Outcome: Seventy-six patients with IDH1/2-mutant glioma had outcome data available. Eighty-four percent of patients with low-grade glioma (LGG) were managed observantly without additional therapy. For low-grade astrocytoma, 5-year progression-free survival (PFS) was 42.9% (95%CI:20.3-63.8) and, despite excellent short-term overall survival (OS), numerous disease-related deaths after year 10 were reported. Patients with high-grade astrocytoma had a 5-year PFS/OS of 36.8% (95%CI:8.8-66.4) and 84% (95%CI:50.1-95.6), respectively. Patients with oligodendroglioma had excellent OS. CONCLUSIONS: A subset of pediatric gliomas is driven by IDH1/2 mutations, with a higher rate among adolescents. The majority of patients underwent upfront observant management without adjuvant therapy. Findings suggest that the natural history of pediatric IDH1/2-mutant glioma may be similar to that of adults, though additional studies are needed.

Using complications associated with postmastectomy radiation and immediate breast reconstruction to improve surgical decision making.

OBJECTIVES: To identify factors independently associated with surgical complications in oncologic and reconstructive surgery and to examine sentinel lymph node (SLN) biopsy data, along with variables that are typically known prior to definitive resection, for their ability to impact the prediction of need for postmastectomy irradiation (PMRT). DESIGN: Retrospective review. SETTING: University hospital. PATIENTS: Mastectomy patients with stage I to III breast cancer treated in 2000 to 2008. MAIN OUTCOME MEASURES: Complication rates of oncologic and reconstructive surgery requiring reoperation and clinicopathologic variables that independently predict complications and/or PMRT administration by multivariate analysis. RESULTS: Among 100 of 302 mastectomy patients who underwent PMRT, complications occurred in 44% who underwent immediate breast reconstruction (IBR) and 7% who did not (P < .001). Postmastectomy irradiation independently predicted the occurrence of a complication (odds ratio, 3.3; P < .001). Implants were removed in 31% of patients who underwent PMRT and 6% of patients who did not (P = .005). Three percent of patients with T2 or smaller tumors and zero positive SLN required PMRT. Among those with T2 tumors, 49% with a positive axilla lymph node underwent PMRT. Independent predictors of PMRT need were T2 vs T1 tumors, positive axillary lymph node status, and the number of positive SLNs, with odds ratios of 5.8 (P < .001), 14.5 (P < .001), and 2.1 (P = .001), respectively. CONCLUSIONS: Postmastectomy irradiation was associated with a high rate of surgical complications and implant loss among patients who underwent IBR. Determining the number of positive SLNs prior to definitive resection and reconstructive operations may reduce complications and implant loss by guiding surgical decision making. Patients with a negative SLN are unlikely to require PMRT. Those with positive SLN(s) are high-risk IBR candidates with a quantifiable PMRT risk.