Pediatric Salivary Cancer: Epidemiology, Treatment Trends, and Association of Treatment Modality with Survival

Objective To characterize the epidemiology of pediatric salivary cancer and associate patient, tumor, and treatment factors with treatment modality and survival. Study Design Cross-sectional analysis. Setting US national database. Subjects and Methods We identified 588 patients 19 years or younger diagnosed with salivary cancer in the National Cancer Database 2004-2013. We characterized patient, tumor, and treatment factors as proportions and associated these factors with treatment modality and overall survival via multivariable logistic regression and multivariable Cox proportional hazards regression, respectively. Results In total, 588 patients were included. Mucoepidermoid carcinoma was identified in 234 of 588 patients (40%) and acinar cell carcinoma in 215 of 588 (37%). Parotid tumors were seen in 504 (86%) of patients. Surgery alone was used to treat 351 (60%) of patients; surgery plus adjuvant radiation was used to treat 145 (25%). Overall 5-year survival was 93%. Controlling for patient and tumor characteristics, treatment with surgery and radiation vs surgery alone was associated with improved overall survival (hazard ratio [HR] = 0.15; 95% confidence interval [CI], 0.02-0.92; P = .041). High tumor grade was associated with decreased overall survival (HR = 33.17; 95% CI, 5.89-186.8; P < .001). Treatment with surgery plus radiation remained associated with improved overall survival in the subset of patients with high tumor grade (HR = 0.12; 95% CI, 0.02-0.64; P = .014). Conclusion Tumor grade is an important predictor of survival in pediatric patients with salivary gland cancer. Surgery plus adjuvant radiation vs surgery alone is associated with improved overall survival and may be considered for high-risk patients, particularly those with high-grade tumors.