Comparison of Long-Term Outcomes and Sequelae Between Children and Adult Nasopharyngeal Carcinoma Treated With Intensity Modulated Radiation Therapy

Purpose: Our purpose was to compare long-term survival outcomes and sequelae between child and adult nasopharyngeal carcinoma (NPC) in the era of intensity modulated radiation therapy. Methods and Materials: Data on 285 patients with NPC aged <= 18 years at diagnosis and treated with intensity modulated radiation therapy between January 2004 and November 2016 were retrospectively reviewed. A propensity score matching method was adopted to screen matched adult patients with NPC at a ratio of 1:3. Survival outcomes and treatment-related toxicities between child and adult groups were compared. Results: In total, 159 children and 477 adult patients with NPC were included in this study. The 5-year overall survival, distant metastasis-free survival, locoregional relapse-free survival, and disease-free survival between children and adults were 89.2% versus 83.6% (P = .144), 88.7% versus 83.5% (P = .124), 96.4% versus 89.1% (P = .013), and 86.5% versus 77.3% (P = .021), respectively. Subgroup analyses revealed that the young age was an independent prognostic factor of overall survival, distant metastasis-free survival, and locoregional relapse-free survival in the advanced N stage (N2-3) group and disease-free survival in the advanced T stage (T3-4) group and N2-3 and stage III-IVA groups. The most common sequela was ototoxicity (68.9%) in child patients and xerostomia (70.8%) in adult patients. Adult survivors had a significantly higher incidence of grade 3 to 4 late toxicities in xerostomia (17.6% vs 8.9%; P = .004), skin dystrophy (9.3% vs 3.7%; P = .022), neck fibrosis (8.3% vs 4.4%; P < .001), and radiation encephalopathy (0.8% vs 0; P = .006). Child survivors were more likely to develop grade 3 to 4 growth retardation and endocrine insufficiency (3.0% vs 0.3%; P = .014). Conclusions: Child patients with NPC achieved significantly better survival outcomes but fewer late toxicities than adult patients. However, we should pay great attention to growth problems of child survivors. (C) 2019 Elsevier Inc. All rights reserved.