For Patients With Neurofibromatosis Type 1, Many Unmet Needs Remain

A large proportion of children diagnosed with neurofibromatosis type 1 (NF1)-related plexiform neurofibromas (PN) have no appropriate treatment available to them and represent a significant unmet medical need. To determine demographics, clinical characteristics, and treatments, a cross-sectional analysis of existing data from the Children’s Tumor Foundation (CTF) registry was undertaken by Jinghua He, PhD, MPH, and colleagues and presented during a poster session at the 24th Annual Meeting and Education Day of the Society of NeuroOncology.

CTF is a web-based, patient-entered registry that has collected data since 2012 and is currently ongoing. For the cross-sectional analysis, data were reviewed from 2012 to 2018. Eligible patients were ≤19 years of age at the time of first survey completion, had completed at least 1 registry survey, and had a diagnosis of NF1 and at least 1 PN reported by a patient or guardian. The investigators conducted descriptive statistical analysis on the data collected based on the first survey of each patient and included patient characteristics and treatment patterns. The results were stratified by region designated as living either within or outside of the United States.

The sample was comprised of 943 pediatric patients, with 750 being from the US and 193 participants from other regions (ex-US). In the US cohort, 87.6% were diagnosed with NF1 at less than 5 years of age, whereas 79.3% of those from other countries were diagnosed with NF1 at less than 5 years of age. About half (52.2%) of those in the overall cohort were male, with rates in the US and ex-US cohorts being 53.3% and 47.7% males, respectively. Overall, 50.3% of patients reported having more than 1 PN, with 50.1% in the US cohort and 50.8% of the ex-US cohort reporting more than 1 PN.

Regarding the location of the PN, patients in the US reported the most common sites as the head (28.8%), neck area (24.8%), the back other than the spine (20.4), and chest area (19.2%). For ex-US patients, the most common sites were the head (35.2%), neck area (25.9%), back other than the spine (24.9%), and chest area (22.8%).

Overall, 57.2% of all participants received no treatment for their PN, with 57.6% in the US cohort and 55.4% in the ex-US cohort. Surgery was the highest-reported treatment, occurring in 29.1% of patients overall, 29.2% of those in the US cohort, and 28.5% in ex-US cohort. Chemotherapy or drug therapy was reported in 10.5%, 10.8%, and 9.3% of patients, respectively. These results were generally consistent across regions.

Secondary complications included malignant peripheral nerve sheath tumors (MPNSTs) and optic gliomas (OGs). MPNST was diagnosed in 21 (2.2%) patients overall, with 2.1% of US and 2.6% of ex-US patients diagnosed. Surgery (61.9%) and radiation (52.4%) were the most common treatments for this type of tumor overall.

OGs were diagnosed in 32.7% of patients overall, with 33.6% of patients in the US group and 29.0% in the ex-US group developing this condition. More than 60% of patients were untreated, with 62.7% in the US cohort, and 55.4% in the ex-US cohort remaining without treatment.

The investigators noted numerous limitations of the study. Because the analysis relied on a self-reported registry, the potential for misclassification of diagnosis, demographic, and clinical data or symptoms can cause selection bias. In addition, the results may not be generalizable to a broader NF1 patient population because of self-selection and restricted sample bias (e.g., English-speaking or computer literate/internet access). Finally, the investigators reported a large percentage of missing data for questions regarding body system affected by PN and visibility of PN may bias the results for these questions.

Reference:

He J, Pinto CA, Yang X, Diede SJ, Deitz AC. Characteristics and treatment patterns in children with neurofibromatosis type 1 (NF1) and plexiform neurofibromas (PN): a cross-sectional analysis of Children’s Tumor Foundation (CTF) registry data.Neuro-Oncology. 2019;21(suppl 6;abstr RARE-13). doi: 10.1093/neuonc/noz175.936.