Malignancies in Chinese patients with neurofibromatosis type 1.

OBJECTIVE To investigate the pattern of malignancies in Chinese patients with neurofibromatosis type 1. DESIGN Historical cohort study. SETTING Queen Mary Hospital and Duchess of Kent Children's Hospital in Hong Kong. PATIENTS Patients with neurofibromatosis type 1 seen between January 1995 and August 2011. RESULTS We identified 123 Chinese patients with neurofibromatosis type 1, diagnosed at a median age of 4.9 years (range, 0.1-16.1 years); 75 (61%) were males. They were followed up for a median of 9.7 years (range, 0.2-27.6 years). Most (80%) of the patients participated in our surveillance programme. Twelve patients developed malignancies at the ages of 0.8 to 41.6 years. These malignancies included: peripheral nerve sheath tumours (n=3), juvenile myelomonocytic leukaemia (n=2), optic nerve glioma (n=1), thalamic pilocytic astrocytoma (n=1), rhabdomyosarcoma (n=1), osteosarcoma (n=1), neuroblastoma (n=1), anaplastic large cell lymphoma (n=1), and breast carcinoma and subsequently carcinoma of the ampulla of Vater (n=1). Among them, three had their tumours (optic glioma, thalamic astrocytoma, sacral malignant peripheral nerve sheath tumour) initially detected by surveillance imaging. Four patients survived without disease progression, three are alive with active disease, the remaining five died (when aged 3 to 56 years) with progressive or relapsed malignancies. The latter patients died from a neuroblastoma, a juvenile myelomonocytic leukaemia, a malignant peripheral nerve sheath tumour, a lymphoma, and a second primary tumour (carcinoma of ampulla of Vater, at the age of 56 years). In neurofibromatosis type 1 patients with malignancy, overall 30-year survival was significantly shorter than in those without malignancy (35% vs 93%, P<0.001). CONCLUSION Chinese patients with neurofibromatosis type 1 are susceptible to different malignancies which contribute to mortality. These findings are similar to reports from overseas. Outcomes were unfavourable, except in patients having low-grade gliomas. Surveillance imaging may help early detection of deep-seated malignancies but the benefits accruing from such monitoring warrants prospective evaluation.