Germline mutations of the breast cancer 1 (BRCA1) gene are a major cause of familial breast and ovarian cancer. The BRCA1 protein displays E3 ubiquitin ligase activity, and this enzymatic function is thought to be required for tumor suppression. To test this hypothesis, we generated mice that express an enzymatically defective Brca1. We found that this mutant Brca1 prevents tumor formation to the same degree as does wild-type Brca1 in three different genetically engineered mouse (GEM) models of cancer. In contrast, a mutation that ablates phosphoprotein recognition by the BRCA C terminus (BRCT) domains of BRCA1 elicits tumors in each of the three GEM models. Thus, BRCT phosphoprotein recognition, but not the E3 ligase activity, is required for BRCA1 tumor suppression.

INFORM is a prospective, multinational registry gathering clinical and molecular data of relapsed, progressive, or high-risk pediatric patients with cancer. This report describes long-term follow-up of 519 patients in whom molecular alterations were evaluated according to a predefined seven-scale target prioritization algorithm. Mean turnaround time from sample receipt to report was 25.4 days. The highest target priority level was observed in 42 patients (8.1%). Of these, 20 patients received matched targeted treatment with a median progression-free survival of 204 days [95% confidence interval (CI), 99–not applicable], compared with 117 days (95% CI, 106–143; P = 0.011) in all other patients. The respective molecular targets were shown to be predictive for matched treatment response and not prognostic surrogates for improved outcome. Hereditary cancer predisposition syndromes were identified in 7.5% of patients, half of which were newly identified through the study. Integrated molecular analyses resulted in a change or refinement of diagnoses in 8.2% of cases. Significance: The pediatric precision oncology INFORM registry prospectively tested a target prioritization algorithm in a real-world, multinational setting and identified subgroups of patients benefiting from matched targeted treatment with improved progression-free survival, refinement of diagnosis, and identification of hereditary cancer predisposition syndromes. See related commentary by Eggermont et al., p. 2677. This article is highlighted in the In This Issue feature, p. 2659

Gorlin syndrome (MIM 109,400), a cancer predisposition syndrome related to a constitutional pathogenic variation (PV) of a gene in the Sonic Hedgehog pathway (PTCH1 or SUFU), is associated with a broad spectrum of benign and malignant tumors. Basal cell carcinomas (BCC), odontogenic keratocysts and medulloblastomas are the main tumor types encountered, but meningiomas, ovarian or cardiac fibromas and sarcomas have also been described. The clinical features and tumor risks are different depending on the causative gene. Due to the rarity of this condition, there is little data on phenotype-genotype correlations. This report summarizes genotype-based recommendations for screening patients with PTCH1 and SUFU-related Gorlin syndrome, discussed during a workshop of the Host Genome Working Group of the European branch of the International Society of Pediatric Oncology (SIOPE HGWG) held in January 2020. In order to allow early detection of BCC, dermatologic examination should start at age 10 in PTCH1, and at age 20 in SUFU PV carriers. Odontogenic keratocyst screening, based on odontologic examination, should begin at age 2 with annual orthopantogram beginning around age 8 for PTCH1 PV carriers only. For medulloblastomas, repeated brain MRI from birth to 5 years should be proposed for SUFU PV carriers only. Brain MRI for meningiomas and pelvic ultrasound for ovarian fibromas should be offered to both PTCH1 and SUFU PV carriers. Follow-up of patients treated with radiotherapy should be prolonged and thorough because of the risk of secondary malignancies. Prospective evaluation of evidence of the effectiveness of these surveillance recommendations is required.