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

ABSTRACT

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 13. 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.