Abstract 6373: Effectiveness of tumor surveillance across pediatric cancer predisposition syndromes

Abstract Background: Pediatric oncology patients are increasingly recognized as having an underlying cancer predisposing syndrome (CPS). For individuals diagnosed with a CPS, surveillance is often recommended to detect new tumors at their earliest and most curable stages. Screening is heavily based on radiologic imaging, however data on the effectiveness and outcomes of surveillance are limited. Methods: Patients with a clinical and/or molecular CPS diagnosis, including 274 children and young adults with 35 CPS at a single specialty pediatric oncology center, were monitored using standardized surveillance protocols over an average of 3 years (range 1 month - 12 years). Patients with hereditary retinoblastoma were excluded as surveillance was completed by a separate team. The cohort included 139 patients (50.7%) with a prior tumor history while 135 (49.3%) had no prior cancer. This study reviewed tumors diagnosed, method of detection, clinical course, and patient outcomes. Individual reports from 1,533 surveillance tests including diagnostic imaging, colonoscopy, and upper endoscopy, were assessed and classified for accuracy. Sensitivity, specificity, positive predictive value (PPV), and negative predictive values (NPV) were calculated for selected surveillance methods, and themes of common strengths or weaknesses of specific imaging modalities were identified. Results: During the study period from January 1, 2009 - September 31, 2021, 35 asymptomatic tumors were detected in 27 patients through surveillance (9.9% of the cohort), while five symptomatic tumors were detected in five patients (1.8%) outside of surveillance. Ten tumors (28.6%) discovered through surveillance were identified on first surveillance imaging. Among these 35 new tumors, 19 (54.3%) were diagnosed in children with a previously treated cancer, six (17.1%) were diagnosed in patients still being treated for cancer, and 10 (28.6%) were diagnosed in those with no prior cancer history. Malignant solid and brain tumors identified through surveillance were more often localized (20 of 24; 83.3%) than similar tumors detected before CPS diagnosis (71 of 125; 56.8%, p ≤0.0001). Of the 24 tumors identified through surveillance and surgically resected, 17 (70.8%) had completely negative margins. When analyzed across all CPS, the sensitivity (96.4%), specificity (99.6%), PPV (95.7%), and NPV (99.6%) of surveillance testing was high, with few false positive (n=6/1,533, 0.4%) or false negative (n=5/1,533, 0.3%) reports. No invasive interventions were performed due to false positive results. Conclusion: Patients with CPS are at increased risk of primary and secondary tumor development with 10% of our cohort developing a tumor in a short time span. Surveillance effectively enabled early detection of new brain and solid tumors across a wide spectrum of CPS which allowed for complete surgical resection and successful treatment in most cases. Citation Format: Melissa R. Perrino, Alise Blake, Cara E. Morin, Leslie Taylor, Rose B. McGee, Sara Lewis, Stacy Hines-Dowell, Arti Pandey, Paige Turner, Manish Kubal, Yin Su, Li Tang, Laura Howell, Lynn W. Harrison, Zachary Abramson, Ann Schechter, Noah D. Sabin, Kim E. Nichols. Effectiveness of tumor surveillance across pediatric cancer predisposition syndromes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6373.