Childhood nasopharyngeal carcinoma: from biology to treatment.

Nasopharyngeal carcinoma is a rare disease in children with distinct epidemiological, histopathological, and clinical characteristics. Incidence varies widely around the world but bimodal incidence graphs show that in some populations a disproporionate number of cases occur in late childhood. Children with nasopharyngeal carcinoma almost always have the undifferentiated variant of the disease, which is associated with advanced locoregional spread and distant metastases. Both genetic and environmental factors contribute to the development of nasopharyngeal carcinoma, as evidenced by its risk factors which include: specific HLA subtypes; deletions of chromosomes 3p, 9p, 11q, 13q, and 14q; mutations of p53 and RB2/p130; polymorphism of the CYP2E1; and infection with Epstein-Barr virus. Traditional treatment consists of high-dose radiotherapy and cure rates range between 30% and 60%. The high incidence of failure due to systemic disease in children means that chemotherapy is preferable for first-line treatment in advanced-stage disease. Currently, cisplatin-based induction or adjuvant chemotherapy combinations are used along with high-dose radiotherapy. Although combined modality treatment has increased 5-year survival to 70-90%, late morbidity is a major concern.