Abstract 755P
Background
Neurofibromatosis type I (NF1) affects about 1 in every 3000 people worldwide. 30-50% NF1 patients develop plexiform neurofibromatosis (PN) which grow rapidly in early childhood and can cause severe complications. This systemic disease imposes a heavy psychosomatic and financial burden on patients and their caregivers.
Methods
We performed a retrospective analysis of the NF1 patients visited the NF1 specific clinic in Shanghai nineth people’s hospital between 2019 and 2022. The prevalence, disease characteristics, progression free survival (PFS) and treatment pattern of NF1-PN were assessed.
Results
Totally 1235 NF1 patients visited the NF1 specific clinic . 55.6% (687/1235) of NF1 patients developed PN. 9 patients with PN were diagnosed as malignant peripheral nerve sheath tumor (MPNST) at the first visit. The median age of patients at PN diagnosis is 13 years old. Most PNs were diagnosed by clinical manifestations and imaging. Head & neck (52.1%), lower limb (23.8%) are the most common locations of PN. 53.5% (363/687) of patients with PN had PN related complications and 74.1% (269/363) of them had more than 1 complication. The most common complications are disfigurement (66.9%), functional abnormality (33.3%) and pain (25.6%). 73.6% (497/687) patients with PN had at least 1 follow-up and 21.1% (143/687) patients received surgery. The mean surgery times patients received is 1.21. 7.7% (11/143) patients had PN complete resected, 40.6% (58/143) patients had PN subtotal resected and 51.7% (74/143) had PN partial resected. 101 of 143 patients received surgery had symptomatic PN. The median PFS of patients with PN evaluated by doctor is 23.4 months (95%CI 21.8∼25.4). The median PFS evaluated by doctor after surgery is 24.5 months (95%CI 17.48∼29.14). 160 patients were evaluated as progression by doctors, 42.5% of progressions were not realized by patients.
Conclusions
The retrospective analysis shows PN can be found in 55.6% NF1 patients and can cause severe disease burden. PN is a progressive disease. Early diagnosis, early treatment and regular follow-up are important to NF1-PN. The decision of treatment timing of NF1-PN needs more evidence in the future.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine.
Funding
Alexion, AstraZeneca.
Disclosure
All authors have declared no conflicts of interest.