Association of Treatment Advances With Survival Rates in Pediatric Patients With Nasopharyngeal Carcinoma in China, 1989-2020

IMPORTANCE: Advanced techniques and treatment methods have been found to be associated with improved survival rates in adults with nasopharyngeal carcinoma (NPC); however, not much is known about associations in pediatric patients. OBJECTIVE: To investigate whether advanced imaging diagnosis, radiotherapy (RT) technology, and treatment modality are associated with survival in pediatric patients with NPC. DESIGN, SETTING, AND PARTICIPANTS: In this retrospective cohort study, 810 pediatric patients ages 21 years and younger with nonmetastatic NPC diagnosed from 1989 to 2020 at a single cancer center in China were included. Data were analyzed from April through December 2021. EXPOSURES: Patients were divided into 3 groups by initial treatment date (ie, 1989-2002, 2003-2011, and 2012-2020). Associations between advances in technology and treatment and survival were investigated. Comparisons of advances vs older technology and treatments included those in imaging diagnosis (magnetic resonance imaging [MRI] vs computed tomography [CT] and positron emission tomography [PET]–CT with MRI vs CT), radiotherapy (RT) techniques (intensity-modulated RT [IMRT] or TomoTherapy [TOMO] vs 2-dimensional conventional radiotherapy [2D-CRT] or 3-dimensional conventional radiotherapy [3D-CRT]), and treatment methods (concurrent chemoradiotherapy [CCRT] vs RT alone, induction chemotherapy [IC] with CCRT vs RT alone, and CCRT or RT with adjuvant chemotherapy [AC] vs RT alone). MAIN OUTCOMES AND MEASURES: The primary end point was progression-free survival (PFS). Secondary end points were overall survival (OS), distant metastasis–free survival, and locoregional recurrence–free survival. Cox and competing-risks regression were used to estimate hazard ratios (HRs) and 95% CIs for associations between variables and survival. RESULTS: Among 810 pediatric patients with NPC, the median (IQR) age was 18 (15-20) years, and there were 577 [71.2%] male patients. This included 122 patients in the 1989 to 2002 period, 212 patients in the 2003 to 2011 period, and 476 patients in the 2012 to 2020 period. The 5-year PFS and OS rates increased, respectively, from 65.9% (95% CI, 56.6%-73.7%) and 69.9% (95% CI, 60.7%-77.4%) in 1989 to 2002 to 79.8% (95% CI, 73.7%-84.7%) and 86.2% (95% CI, 80.6%-90.3%) in 2003 to 2011, then 88.1% (95% CI, 84.2%-91.1%) and 95.0% (95% CI, 91.5%-97.0%) in 2012 to 2020. The 5- year cumulative incidence of distant metastasis rate was similar in the 3 periods (1989-2002: 11.7% [95% CI, 7.0%- 19.4%]; 2003-2011: 18.0% [95% CI, 13.4%-24.0%]; 2012-2020: 10.4% [95% CI, 7.6%-14.1%], while the 5-year cumulative incidence of locoregional recurrence rate decreased from 22.5% (95% CI, 15.9%-31.3%) in the first period to 2.9% (95% CI, 1.3%-6.3%) in the second period, remaining stable in the third period, at 4.3% (95% CI, 2.4%-7.6%). Advances in imaging diagnosis (MRI vs CT: hazard ratio [HR], 0.25 [95% CI, 0.17-0.38]; PET-CT with MRI vs CT: HR, 0.41 [95% CI, 0.27-0.62]), radiotherapy techniques (IMRT or TOMO vs 2D-CRT or 3D-CRT: HR, 0.42 [95% CI, 0.30-0.59]), and treatment methods (CCRT vs RT alone: HR, 0.55 [95% CI, 0.32-0.96]; IC with CCRT vs RT alone: HR, 0.59 [95% CI, 0.38-0.91]; CCRT or RT with AC vs RT alone: HR, 0.48 [95% CI, 0.25-0.91]) were associated with improved PFS. CONCLUSIONS AND RELEVANCE: This study found that advanced techniques and treatment methods were associated with improved survival rates in pediatric patients with NPC, but distant failure remained a key challenge.