K. Mahendraraj1, R. S. Chamberlain1,2,3 1Saint Barnabas Medical Center,Department Of Surgery,Livingston, NJ, USA 2New Jersey Medical School,Department Of Surgery,Newark, NJ, USA 3Saint George’s University,Department Of Surgery,Grenada, Grenada, Grenada
Introduction:
Salivary gland carcinomas are rare in adults and children, the most common form being mucoepidermoid carcinoma (MEC). Small cohort studies suggest different clinical characteristics of MEC in adults compared to children. This study sought to analyze demographic and clinical factors which affect outcomes in adult and pediatric patients that may be used to risk stratify patients for treatment and clinical trial accrual.
Methods:
Demographic and clinical data on 4,234 patients with MEC was abstracted from the Surveillance Epidemiology and End Result (SEER) database (1973-2010). Children were defined as age ≤ 21 and adults as >22. Standard statistical methodology was used.
Results:
Among 4,234 MEC patients, 221 (5.2%) were children and 4,013 (94.8%) were adults. The majority of pediatric MEC occurred in females (55.7%), while most adults MEC patients were male (50.6%), p<0.001. Overall, 71% of MEC occurred in Caucasians, p<0.001. Among African-Americans and Hispanics, there were more pediatric patients than adults (16.3% vs. 10%, and 20.8% vs. 8.3%, respectively; p<0.001). Adults had a higher rate of poorly differentiated disease (12.6% vs. 2.7%) and metastasis (7.7% vs. 3.6%) compared to children, p<0.001. Most children (53.8%) and adults (44.8%) presented with tumor size 2-4 cm. 51.1% of all patients underwent surgery and 41% had combination surgery and radiotherapy. More children underwent primary surgical resection alone (64.3% vs. 50.4%), while more adults had combination surgery and radiotherapy (41.4% vs. 33.0%); p<0.001. Mean overall survival (OS) was significantly longer in children than adults (34.5 vs. 18.7 years), p<0.001. Surgical resection significantly improved OS in children (34.9±0.5 vs. 22.6±0.5 years; p<0.001). Children had a lower overall mortality (3.6% vs. 38.0%) as well as higher 5-year cancer-specific survival (98% vs. 82%). Multivariate analysis identified adults (OR 10.4), tumor size greater than 2 cm (OR 1.9), poor (OR 4.0) or undifferentiated grade (OR 5.0), regional disease stage (OR 1.5), and lymph node invasion (OR 1.6) as associated with increased mortality, p<0.05.
Conclusion:
MEC is an aggressive salivary gland cancer that is predominantly found in Caucasians. It is far more common in adults, and is associated with more advanced stage, poorer grade and worse overall prognosis compared to children. While MEC presented with similar tumor size in both age groups, tumors in children occurred less frequently, were more often localized, well differentiated and had better outcomes. Surgical resection significantly improved OS in MEC patients, particularly among children. Older age and advanced tumor stage were associated with increased mortality.
