Puberty and plexiform neurofibroma tumor growth in patients with neurofibromatosis type I.

OBJECTIVE

To assess the relationship between pubertal progression and change in plexiform neurofibroma (PN) burden over time in pediatric and young adult patients with neurofibromatosis type 1 and PNs.

METHODS

Analyses accounted for sex, age, race, and chemotherapy. Forty-one patients with neurofibromatosis type 1 (15 female and 26 male patients) were studied at the National Institutes of Health. 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 locally. Patients were divided into 2 groups based on whether they were actively progressing through puberty (n = 16) or were peripubertal (n = 25) and were followed for an average of 20 months. Tumor growth rates in the puberty and peripubertal group were analyzed for a subset of patients.

RESULTS

There was no statistically significant difference in tumor burden change over time (cm(2)/kg per month) between the pubertal and peripubertal groups (-0.16 ± 0.34 vs 0.03 ± 1.8, P = .31) and in the PN growth rates before and during puberty (P = .90). Change in tumor volume/patient weight/time did not correlate with testosterone change/time in males or estradiol change/time in females.

CONCLUSIONS

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.