T. K. Woleston1,3, K. Mahendraraj1, R. S. Chamberlain1,2,3 1Saint Barnabas Medical Center,Department Of Surgery,Livingston, NJ, USA 2Rutgers University, New Jersey Medical School,Department Of Surgery,Newark, NJ, USA 3St. George’s University School Of Medicine,St. George’s, ST. GEORGE’S, Grenada
Introduction: Giant cell tumors of the bone (GCT) are very rare in the pediatric population, with an incidence of 1.8%-10.6%. GCT are typically benign, although malignant GCTs have been described and are poorly understood based on the few case series published. This study reports the largest cohort of GCT patients from the SEER database to better characterize clinical and pathologic factors associated with pediatric and adult GCT cases.
Methods: Demographic and clinical data on 281 GCT patients was abstracted from the SEER database (1973-2010). Pediatric patients were defined as those aged ≤19. Data was analyzed using the Chi square test, t-test, and multivariate analysis. Kaplan-Meier analysis was used to compare long-term survival between groups.
Results: Among 281 GCT patients, 48 (17%) were pediatric (mean age 18±2), and 233 (82.9%) were adult (mean age 42±16). GCT was significantly more common among pediatric females (58.3% vs. 41.7%, female vs. male, p<0.001), compared to a more evenly distributed adult group (F:M=1:1, p<0.001). While GCT was most common overall among Caucasians (48.9% and 59.6%, p<0.001), it was significantly more common among pediatric Hispanics than adults (33% vs.16.5%, p=0.01). Pediatric GCT was more often well differentiated (22% vs.18.2%), localized (54.5% vs. 46.2%), had size <2 cm (4.5% vs. 0%), and had a lower lymph node positivity rate (0% vs. 1.7%), although none were statistically significant. Surgery was the most common therapy in both groups (75.6% and 63.2%, p=0.07), and was the only treatment associated with significant improvement in both pediatric (36.6±0.9, p<0.001) and adult (28.9 ± 1.3, p<0.001) survival. Cancer-specific mortality was significantly lower in the pediatric group (2.1% vs. 16.8%, p<0.001), and median survival significantly longer (13.9±5.7 years vs. 9.1±5.3 years, p<0.001). Multivariate analysis identified distant metastases (OR 2.6, CI=1.2-5.7) as the only risk factor for increased mortality among pediatric patients, p=0.021.
Conclusions: Pediatric GCT has higher incidence among females and Hispanics compared to adult GCT. Clinicians should consider the possibility of GCT in a symptomatic patient from these populations. Pediatric GCT was observed to be more often well differentiated and localized, with size <2 cm, no lymph node positivity, and significantly longer survial. Surgical resection was the most common treatment and conferred the longest survival advantage in both groups. Resection should be considered in pediatric GCT patients with resectable disease. Adult GCT patients should be considered for clinical trial accrual given their relative rarity, and increased cancer-specific mortality.
