Differential features of nasopharyngeal carcinoma in children and adults: A SEER study

Abstract

Nasopharyngeal carcinoma (NPC) is a rare malignancy in the United States, which is considered a low-risk country. We searched the surveillance, epidemiology, and end results (SEER) database for patients with NPC who were diagnosed from 1988 to 2006. We compared the clinical features and outcomes of children and adolescents (<20 years old) and adults. The incidence for children and adolescents was 0.5 per million person-years versus 8.4 in adults. NPC was less rare in black children and adolescents (incidence, 1.5 per million person-years). Our search criteria retrieved 129 children and adolescents and 5,885 adults. Black children and adolescents represented 34.9% of patients below the age of 20 years. Younger patients had distinct features with advanced stages more frequently observed (31% and 46% of children and adolescents had stages III and IV, respectively) and 87% had WHO type III histology. Outcome was better in children and adolescents with 5-year NPC-specific survival of 83% +/- 3.9% compared to 62% +/- 0.8% in adults (P < 0.001). In a multivariate model, the following factors affected the outcome: age, race, stage, and histologic type. Young adults (20-45 years old) had almost double the risk of NPC-specific mortality when compared to children and adolescents [hazards ratio (HR), 1.93; P = 0.0077]. Children and adolescents with NPC were at higher risk of getting second cancer than adults (observed-to-expected ratio of 4.36 in children and adolescents; vs. 1.41 in adults; both were significantly higher than general population). Despite the use of similar treatment approaches, NPC in children and adolescents may have different biologic features. Young patients are at higher risk of developing therapy related complications, including second cancer.