Anthropometric measurements of children with neurofibromatosis type I: impact of plexiform neurofibroma volume and treatment

BACKGROUND: In children and adolescents/young adults (CAYA) with neurofibromatosis type I (NF1), associations between anthropometric measurements, plexiform neurofibroma (pNF) tumor volume (TV), and treatment history are unknown. METHODS: We retrospectively investigated anthropometrics in CAYA on the National Cancer Institute (NCI) NF1 Natural History Study who had pNF TV assessed by imaging (n = 106). We determined CDC height/weight percentiles and estimated Preece-Baines (PB) height growth curve parameters. We evaluated variables that could impact height/weight including: (1) pNF volume, (2) pNF directed therapy, and (3) serum IGF-1. RESULTS: 23% of males and 20% of females had height <5th percentile; 13% of males had weight <5th percentile. Estimated median final adult height for males was 171.6 cm (CDC 23rd percentile) and for females was 156.2 cm (CDC 14th percentile). Inverse associations between height and weight percentiles and pNF volume were observed (Spearman's r = -0.277, -0.216, respectively). Estimated median final height was not meaningfully affected by patients who received pNF-directed treatment with MEK inhibitor. 52% of low serum IGF-1 measurements were concurrent with a height percentile <5th. CONCLUSIONS: Greater than expected percentages of patients had height/weight <5th percentile, and median final adult heights were <CDC 25th percentile. pNF volume was inversely associated with height/weight percentiles.