Speaking genomics to parents offered germline testing for cancer predisposition: Use of a 2-visit consent model.

BACKGROUND: Patients with cancer are increasingly offered genomic sequencing, including germline testing for cancer predisposition or other disorders. Such testing is unfamiliar to patients and families, and clear communication is needed to introduce genomic concepts and convey risk and benefit information. METHODS: Parents of children with cancer were offered the opportunity to have their children's tumor and germline examined with clinical genomic sequencing. Families were introduced to the study with a 2-visit informed consent model. Baseline genetic knowledge and self-reported literacy/numeracy were collected before a study introduction visit, during which basic concepts related to genomic sequencing were discussed. Information was reinforced during a second visit, during which informed consent was obtained and a posttest was administered. RESULTS: As reflected by the percentage of correct answers on the pretest and posttest assessments, this model increased genetic knowledge by 11.1% (from 77.8% to 88.9%; P < .0001) in 121 parents participating in both the study introduction and consent visits. The percentage of parents correctly identifying the meaning of somatic and germline mutations increased significantly (from 18% to 59% [somatic] and from 31% to 64% [germline]; P < .0001). Nevertheless, these concepts remained unfamiliar to one-third of the parents. No relation was identified between the change in the overall percentage of correct answers and self-reported literacy, numeracy, or demographics. CONCLUSIONS: The use of a 2-visit communication model improved knowledge of concepts relevant to genomic sequencing, particularly differences between somatic and germline testing; however, these areas remained confusing to many participants, and reinforcement may be necessary to achieve complete understanding.

Integrating next-generation sequencing into pediatric oncology practice: An assessment of physician confidence and understanding of clinical genomics.

BACKGROUND: The incorporation of genomic testing to identify targetable somatic alterations and predisposing germline mutations into the clinical setting is becoming increasingly more common. Despite its potential usefulness, to the authors' knowledge physician confidence with regard to understanding and applying genomic testing remains unclear, particularly within the realm of pediatric oncology. METHODS: Before initiating an institutional feasibility study regarding the integration of clinical genomic testing, the authors surveyed pediatric oncologists regarding their confidence around understanding of genomic testing, perceived usefulness of test results, preferences around the disclosure of germline test results, and possible risks and benefits of testing. RESULTS: Among survey respondents (52 of 88 contacted; response rate of 59%), only a minority were confident in interpreting, using, and discussing somatic (35%) or germline (27%) genomic test results. Providers who were confident in interpreting somatic results were significantly more likely to anticipate using the results to plan the treatment of patients with relapsed or refractory cancers (P = .009). Similarly, providers who reported confidence in interpreting germline results were significantly more likely to discuss and use these results as part of clinical care (P<.0001). The majority of physicians (93%), regardless of their level of confidence, wanted to speak to a genetic counselor before disclosing germline test results. CONCLUSIONS: Among physicians at a comprehensive pediatric cancer center, confidence in the interpretation, use, and discussion of oncology-based genomic test results appears to be low, both in terms of somatic and germline testing. To optimize the integration of genomic sequencing into cancer care, methods must be developed to improve basic competencies around cancer-based genomic testing. Given the complexities surrounding variant interpretation and genotype-phenotype relationships, interdisciplinary collaborations are warranted. Cancer 2017;123:2352-2359. © 2017 American Cancer Society.

Pathogenic Variants in Adult-Onset Cancer Predisposition Genes in Pediatric Cancer: Prevalence and Impact on Tumor Molecular Features and Clinical Management.

PURPOSE: Clinical genomic sequencing of pediatric tumors is increasingly uncovering pathogenic variants in adult-onset cancer predisposition genes (aoCPG). Nevertheless, it remains poorly understood how often aoCPG variants are of germline origin and whether they influence tumor molecular profiles and/or clinical care. In this study, we examined the prevalence, spectrum, and impacts of aoCPG variants on tumor genomic features and patient management at our institution. EXPERIMENTAL DESIGN: This is a retrospective study of 1,018 children with cancer who underwent clinical genomic sequencing of their tumors. Tumor genomic data were queried for pathogenic variants affecting 24 preselected aoCPGs. Available tumor whole-genome sequencing (WGS) data were evaluated for second hit mutations, loss of heterozygosity (LOH), DNA mutational signatures, and homologous recombination deficiency (HRD). Patients whose tumors harbored one or more pathogenic aoCPG variants underwent subsequent germline testing based on hereditary cancer evaluation and family or provider preference. RESULTS: Thirty-three patients (3%) had tumors harboring pathogenic variants affecting one or more aoCPGs. Among 21 tumors with sufficient WGS sequencing data, six (29%) harbored a second hit or LOH affecting the remaining aoCPG allele with four of these six tumors (67%) also exhibiting a DNA mutational signature consistent with the altered aoCPG. Two additional tumors demonstrated HRD, of uncertain relation to the identified aoCPG variant. Twenty-one of 26 patients (81%) completing germline testing were positive for the aoCPG variant in the germline. All germline-positive patients were counseled regarding future cancer risks, surveillance, and risk-reducing measures. No patients had immediate cancer therapy changed due to aoCPG data. CONCLUSIONS: AoCPG variants are rare in pediatric tumors; however, many originate in the germline. Almost one third of tumor aoCPG variants examined exhibited a second hit and/or conferred an abnormal DNA mutational profile suggesting a role in tumor formation. aoCPG information aids in cancer risk prediction but is not commonly used to alter the treatment of pediatric cancers.

Genomes for Kids: The Scope of Pathogenic Mutations in Pediatric Cancer Revealed by Comprehensive DNA and RNA Sequencing.

Genomic studies of pediatric cancer have primarily focused on specific tumor types or high-risk disease. Here, we used a three-platform sequencing approach, including whole-genome sequencing (WGS), whole-exome sequencing (WES), and RNA sequencing (RNA-seq), to examine tumor and germline genomes from 309 prospectively identified children with newly diagnosed (85%) or relapsed/refractory (15%) cancers, unselected for tumor type. Eighty-six percent of patients harbored diagnostic (53%), prognostic (57%), therapeutically relevant (25%), and/or cancer-predisposing (18%) variants. Inclusion of WGS enabled detection of activating gene fusions and enhancer hijacks (36% and 8% of tumors, respectively), small intragenic deletions (15% of tumors), and mutational signatures revealing of pathogenic variant effects. Evaluation of paired tumor-normal data revealed relevance to tumor development for 55% of pathogenic germline variants. This study demonstrates the power of a three-platform approach that incorporates WGS to interrogate and interpret the full range of genomic variants across newly diagnosed as well as relapsed/refractory pediatric cancers. SIGNIFICANCE: Pediatric cancers are driven by diverse genomic lesions, and sequencing has proven useful in evaluating high-risk and relapsed/refractory cases. We show that combined WGS, WES, and RNA-seq of tumor and paired normal tissues enables identification and characterization of genetic drivers across the full spectrum of pediatric cancers. This article is highlighted in the In This Issue feature, p. 2945.