Concern for impaired bone health in children with neurofibromatosis type 1 (NF-1) has led to increased interest in bone densitometry in this population. Our study assessed bone mineral apparent density (BMAD) and whole-body bone mineral content (BMC)/height in pediatric patients with NF-1 with a high plexiform neurofibroma burden. Sixty-nine patients with NF-1 (age range 5.2–24.8; mean 13.7±4.8 years) were studied. Hologic dual-energy X-ray absorptiometry scans (Hologic, Inc., Bedford, MA, USA) were performed on all patients. BMD was normalized to derive a reference volume by correcting for height through the use of the BMAD, as well as the BMC. BMAD of the lumbar spine (LS 2–4), femoral neck (FN), and total body BMC/height were measured and Z-scores were calculated. Impaired bone mineral density was defined as a Z-score ≤−2. Forty-seven percent of patients exhibited impaired bone mineral density at any bone site, with 36% at the LS, 18% at the FN, and 20% total BMC/height. BMAD Z-scores of the LS (−1.60±1.26) were more impaired compared with both the FN (−0.54±1.58; P=0.0003) and the whole-body BMC/height Z-scores (−1.16±0.90; P=0.036). Plexiform neurofibroma burden was negatively correlated with LS BMAD (rs=−0.36, P=0.01). In pediatric and young adult patients with NF-1, LS BMAD was more severely affected than the FN BMAD or whole-body BMC/height.
Objective
To assess the relationship between pubertal progression and change in PN burden over time in pediatric and young adult patients with neurofibromatosis type 1 (NF1) and plexiform neurofibromas (PN).
Study design
Analyses accounted for sex, age, race, and chemotherapy. Forty-one patients with NF1 (15 female, 26 male) were studied at the National Cancer Institute (NCI). Tanner stage, testosterone, progesterone, estradiol, insulin-like growth factor −1, luteinizing hormone, and follicle stimulating hormone were assessed. Tumor volume was measured using Magnetic Resonance Imaging and lesion detection software developed at NIH. Patients were divided into two groups based upon whether they were actively progressing through puberty (n=16) or peri pubertal (n=25), and were followed for an average of 20 months. Tumor growth rates in the puberty and peri pubertal group were analyzed for a subset of patients.
Results
There was no statistically significant difference in tumor burden change over time (cc/kg/month) between the pubertal and peri pubertal group (−0.16 ± 0.34 vs. 0.03 ± 1.8, p=0.31), and in the PN growth rates pre and during puberty (p=0.90). Change in tumor volume/patient weight/time did not correlate with testosterone change/time in males or estradiol change/time in females.
Conclusion
These findings support that hormonal changes of puberty do not accelerate PN growth. Additional long-term follow up of patients is necessary to further characterize the interaction between puberty and tumor growth.
SRS appears to be less sensitive than conventional imaging at detecting the full extent of metastatic disease in children and adolescents with hereditary MTC. SRS incompletely identified sites of tumor and failed to visualize small sites of tumor or liver and lung metastases, and it has a limited role in the evaluation of metastatic disease in pediatric MTC patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.