The Pediatric Cancer Genome Project

Abstract

The St. Jude Children’s Research Hospital–Washington University Pediatric Cancer Genome Project (PCGP) is participating in the international effort to identify somatic mutations that drive cancer. These cancer genome sequencing efforts will not only yield an unparalleled view of the altered signaling pathways in cancer but should also identify new targets against which novel therapeutics can be developed. Although these projects are still deep in the phase of generating primary DNA sequence data, important results are emerging and valuable community resources are being generated that should catalyze future cancer research. We describe here the rationale for conducting the PCGP, present some of the early results of this project and discuss the major lessons learned and how these will affect the application of genomic sequencing in the clinic.

Figure 1

Frequency of cancer diagnoses and leukemia subtypes in children and adults. (a) The frequency of cancer types in children (left) and adults (right) on the basis of 2012 Surveillance, Epidemiology and End Results (SEER) data. Each chart is organized with cancers listed from the most common to the least common in a clockwise fashion. (b) The frequency of T-cell lineage (blue text) and B-cell lineage (black text) subtypes of acute lymphoblastic leukemia (ALL) in children (left) and adults (right). Each chart is organized with ALL subtypes listed from the most common to the least common in a clockwise fashion. iAMP21, intrachromosomal amplification of chromosome 21.

Figure 2

Genetic landscape of 15 different types of pediatric cancers determined from whole-genome sequencing of 260 tumors and matching germline samples. The number of somatic mutations in each sample, including single-nucleotide variations (SNVs), insertion and/or deletion events (indels) and structural variations, is shown as the height in the three-dimensional graph. Only high-quality variations or validated somatic mutations are included in the summary. CDS, protein-coding regions; tier 1, mutations in annotated genes; tier 2, mutations in non-coding conserved or regulatory regions; tier 3, mutations in non-repetitive, non-coding and non-conserved regions; tier 4, mutations in repetitive regions. Tier 2 and tier 3/tier 4 mutations were rescaled to 1/10 and 1/100 of the original counts to maintain a consistent scale with the results for other somatic lesions. INF, infant ALL; CBF, core-binding-factor acute myeloid leukemia; TALL, T-cell ALL; AMLM7, acute megakaryoblastic leukemia; HYPO, hypodiploid ALL; PHALL, Philadelphia chromosome–positive BCR-ABL1 ALL; RB, retinoblastoma; RHB, rhabdomyosarcoma; NBL, neuroblastoma; OS, osteosarcoma; ACT, adrenocortical carcinoma; HGG, high-grade glioblastoma; LGG, low-grade glioma; EPD, ependymoma; MB, medulloblastoma.