CGH evaluation of two de novo synchronous tumors in a child with a germline p53 mutation

Synchronous occurrence of acute lymphoblastic leukemia and wilms tumor in two patients: underlying etiology and combined treatment plan

Synchronous cancers are extraordinarily rare in pediatric patients and present a therapeutic challenge. Patient A presented with synchronous unilateral Wilms tumor (WT) and standard-risk (SR) B-precursor acute lymphoblastic leukemia (ALL). Genetic testing revealed bialleleic BRCA2/FANCD1 mutations. Patient B, after SR B-precursor ALL induction therapy, was noted on fever workup to have a renal mass; pathology demonstrated lesion indeterminate between WT and nephrogenic rest. Therapy was customized for each patient to treat both cancers. Both patients have ongoing remission from their cancers, without excessive toxicity. We report two regimens for treating synchronous WT and ALL and recommend screening such patients for cancer predisposition.

De novo germline TP53 mutation presenting with synchronous malignancies of the central nervous system

We present a case of a 14-year-old male with a germline TP53 mutation who presented with synchronous primitive neuroectodermal tumor and choroid plexus carcinoma. Identification of synchronous brain tumors prompted genetic testing for predisposition to malignancy. Within 5 months of presentation, the child developed widely metastatic alveolar rhabdomyosarcoma. Patient DNA sequencing showed a TP53 allele with a premature stop codon in the oligomerization/nuclear export signal (NES) domain (R342ter). The child's parents, younger brother, paternal grandparents, and maternal grandmother, are without history of malignancy. The patient's brother tested negative for TP53 mutations. This case identifies a rare, de novo, germline TP53 mutation presenting with synchronous CNS malignancies and exhibiting a more fulminant course than typical cases of Li-Fraumeni syndrome.

TP53 germline mutations in Portugal and genetic modifiers of age at cancer onset

The Li-Fraumeni syndrome (LFS) is a rare, autosomal dominant disease caused by TP53 germline mutations. This study aimed to characterize the TP53 mutational spectrum in patients suspected to have LFS in Portugal and to evaluate the influence of the MDM2-SNP309 and TP53-72Arg variants and of telomere length on age of tumor onset. Probands were primarily selected using the classical LFS criteria (two cases) or the more sensitive Chompret Li-Fraumeni-like (LFL) criteria (13 cases), but 12 additional patients that did not comply with those LFS or LFL criteria were included in the analysis based on clinical suspicion (LFS suspects). Nine of the 27 probands (33.3%) presented germline TP53 mutations, two of them occurring de novo and two of them being novel. Three of the nine TP53 mutations were found in families that did not comply with any of the commonly used criteria for TP53 testing, leaving room to recommend the use of less stringent criteria. An association was found between the presence of the TP53-72Arg (but not the MDM2-SNP309) variant and earlier age of onset in TP53 carriers. A negative correlation between telomere length and age of cancer onset was found in patients with germline TP53 mutation, whereas no such correlation was found in controls or in patients with wild-type TP53.