ID #865 Comparative time to next treatment and durability of response across treatment modalities in pediatric low-grade gliomas: a retrospective chart review
Margaret Shatara, Allison Galkowski, Russell Wolters, Katie Elwell, Amy Linabery, Maggie Skrypek, Anne BendelAbstract
Background
Pediatric low-grade gliomas (pLGGs) represent the most common CNS tumors in children and are characterized by excellent overall survival but a chronic disease course marked by recurrence and treatment-related morbidity. Standard management includes surgical resection, chemotherapy, and molecularly targeted therapies. Time to next treatment (TTNT) and duration of response (DoR) reflect patterns of disease control and treatment durability, yet comparative data across therapeutic modalities are lacking.
Methods
We performed a single-center retrospective cohort study of pLGG patients aged 0–25 years and treated at Children’s Minnesota between January 1, 2002 and August 31, 2025. Clinical, radiographic, pathologic, and molecular data were abstracted into a REDCap database. TTNT was defined as the interval from completion of a treatment line to initiation of subsequent therapy, and DoR as the interval from first documented response (per RAPNO criteria) to disease progression or last follow-up. TTNT and DoR were calculated using Kaplan–Meier methods.
Results
217 patients met eligibility criteria. Median age at diagnosis was 7.1 years, and 10.6% had a cancer predisposition syndrome, most commonly Neurofibromatosis type 1. Surgical intervention was performed in 95% of patients, with gross total resection achieved in 66.3%. All patients who did not undergo surgery had optic pathway glioma. Additional therapy was required in 22.2% of patients, most frequently carboplatin/vincristine. Surgery yielded superior disease control, with median TTNT and DoR not reached. In contrast, upfront chemotherapy was associated with a significantly shorter median TTNT of 2.5 months and a median DoR of 24.7 months (p<0.0001). Disease progression occurred in 49.6% of patients, predominantly radiographically. Following progression, subsequent therapies were associated with a short median TTNT of 1.9 months and a median DoR of 53.9 months, with no significant difference observed between treatment regimens.
Conclusions
In this large pLGG cohort, initial surgical management provided the most durable disease control. Upfront chemotherapy was associated with significantly reduced treatment-free intervals and less durable responses. These data underscore critical differences in longitudinal outcomes across treatment modalities. Ongoing analyses will be presented at the meeting, including detailed comparisons of TTNT and DoR across specific chemotherapy regimens and targeted agents in frontline and relapsed settings.