O3294: Optimizing Surveillance Strategies for Sacrococcygeal Teratoma: A Midwest Pediatric Surgery Consortium Multi-Institutional Study

Background: Evidence-based standardized surveillance strategies following resection of sacrococcygeal teratomas (SCT) is lacking. This study investigated surveillance practices and recurrence rates for children with SCT with the goal of developing surveillance guidelines that optimize detection of recurrence and malignant transformation while minimizing cost and burden for low-risk patients.

Methods: Surveillance strategies and recurrence-free survival (RFS) were evaluated among children undergoing SCT resection at 11 U.S. children’s hospitals from 2010-2020. RFS was compared using Kaplan-Meier analysis, log-rank tests, and Cox proportional hazards models.

Results: 203 patients underwent SCT resection at a median age of 6 days (interquartile range [IQR]: [2, 210]). 25/203 patients had associated Currarino syndrome with a median age at resection of 252 days (IQR: [100, 396]). Initial histopathology revealed 135 mature teratomas (MT) (67.0%), 47 immature teratomas (IT) (23.0%), and 20 malignant germ cell tumors (MGCT) (9.9%). All Currarino patients had MT (Table 1). Median postoperative follow-up for the entire cohort was 3.2 years (IQR: [1.8, 4.9]). Alpha fetoprotein (AFP) was obtained at a median of 2.2 times per year (IQR: [0.96, 3.5]), and imaging was performed 0.84 times per year (IQR: [0.0, 2.0]). RFS for the entire cohort was 93.95%, 89.68%, and 89.68% at 1-, 3-, and 5-years post-resection, respectively. The predominant imaging modality used for surveillance was magnetic resonance imaging (MRI), accounting for 65% of all conducted studies, while ultrasound accounted for 19%, computerized tomography (CT) for 14%, and other modalities for 1.5%. Nineteen recurrences (8.4%) were detected by abnormal AFP (n=10, 52.6%), surveillance imaging (n=6, 31.6%), physical examination (n=1, 5.3%), or other means (n=2, 10.5%). 16/19 recurrences were identified within the initial 3 years of surveillance after resection at a median time of 6.44 months (IQR: [2.5, 15.8]). Seven cases had discordant pathology from the initial resection (Table 2), with 10 MGCT identified at recurrence. In multivariable analyses, no statistically significant variables were associated with recurrence other than initial MGCT pathology (HR 6.1 compared to MT; 1.63-22.6, p=0.007).

Conclusion: Recurrence following SCT resection is uncommon, usually occurs early, and is often indicative of malignant histopathology. Those with initial malignant pathology are at increased risk of malignant recurrence and require standard oncologic surveillance. For children with lower risk tumors (MT, IT) surveillance with imaging, tumor markers, and physical examination should occur for at least 3 years post-resection, but frequency of surveillance and type of imaging modality requires further investigation to maximize sensitivity while minimizing morbidity and cost burden.