Importance: Pediatric cancers represent a unique case with respect to cancer genomics and precision medicine, as the mutation frequency is low, and targeted therapies are less available. Consequently, it is unknown whether clinical sequencing can be of benefit.
Objective: To assess the feasibility of identifying actionable alterations and making individualized cancer therapy (iCat) recommendations in pediatric patients with extracranial solid tumors.
Design, setting, and participants: Clinical sequencing study at 4 academic medical centers enrolling patients between September 5, 2012, and November 19, 2013, with 1 year of clinical follow-up. Participants were 30 years or younger with high-risk, recurrent, or refractory extracranial solid tumors. The data analysis was performed October 28, 2014.
Interventions: Tumor profiling performed on archived clinically acquired specimens consisted of mutation detection by a Sequenom assay or targeted next-generation sequencing and copy number assessment by array comparative genomic hybridization. Results were reviewed by a multidisciplinary expert panel, and iCat recommendations were made if an actionable alteration was present, and an appropriate drug was available.
Main outcomes and measures: Feasibility was assessed using a 2-stage design based on the proportion of patients with recommendations.
Results: Of 100 participants (60 male; median [range] age, 13.4 [0.8-29.8] years), profiling was technically successful in 89 (89% [95% CI, 83%-95%]). Median (range) follow-up was 6.8 (2.0-23.6) months. Overall, 31 (31% [95% CI, 23%-41%]) patients received an iCat recommendation and 3 received matched therapy. The most common actionable alterations leading to an iCat recommendation were cancer-associated signaling pathway gene mutations (n = 10) and copy number alterations in MYC/MYCN (n = 6) and cell cycle genes (n = 11). Additional alterations with implications for clinical care but not resulting in iCat recommendations were identified, including mutations indicating the possible presence of a cancer predisposition syndrome and translocations suggesting a change in diagnosis. In total, 43 (43% [95% CI, 33%-53%]) participants had results with potential clinical significance.
Conclusions and relevance: A multi-institution clinical genomics study in pediatric oncology is feasible and a substantial proportion of relapsed or refractory pediatric solid tumors have actionable alterations.
Trial registration: clinicaltrials.gov Identifier: NCT01853345.