Bonald C. Figueiredo

An inherited p53 mutation that contributes in a tissue-specific manner to pediatric adrenal cortical carcinoma

The incidence of pediatric adrenal cortical carcinoma (ACC) in southern Brazil is 10–15 times higher than that of pediatric ACC worldwide. Because childhood ACC is associated with Li-Fraumeni syndrome, we examined the cancer history and p53 status of 36 Brazilian patients and their families. Remarkably, 35 of 36 patients had an identical germ-line point mutation of p53 encoding an R337H amino acid substitution. Differences within intragenic polymorphic markers demonstrated that at least some mutant alleles arose independently, thus eliminating a founder effect. In tumor cells, the wild-type allele was deleted, and mutant p53 protein accumulated within the nuclei. Although these features are consistent with Li-Fraumeni syndrome-associated adrenal tumors, there was no history of increased cancer incidence among family members. Therefore, this inherited R337H p53 mutation represents a low-penetrance p53 allele that contributes in a tissue-specific manner to the development of pediatric ACC.

Clinical and Outcome Characteristics of Children With Adrenocortical Tumors: A Report From the International Pediatric Adrenocortical Tumor Registry

PURPOSE We created a registry for pediatric adrenocortical tumors (ACTs), which are rare and are not well characterized. We provide a descriptive analysis of 254 patients registered on the International Pediatric Adrenocortical Tumor Registry. PATIENTS AND METHODS Between January 1990 and December 2001, 254 patients younger than 20 years of age with newly diagnosed or previously treated ACTs were registered. A histologic diagnosis of ACT was required, although central review was not mandatory. Follow-up information was periodically requested from the referring physician. Treatment was chosen by the primary physician. RESULTS The overall female-male ratio was 1.6:1, but it varied widely among age groups. The most common presenting sign (84.2%) was virilization. Cushings syndrome without virilization was uncommon (5.5%). Tumors were completely resected in 83% of patients. Patients with disseminated or residual disease received mitotane, cisplatin, etoposide, and/or doxorubicin, and rarely, radiation therapy. At a median follow-up of 2 years and 5 months, 157 patients (61.8%) survived without evidence of disease and 97 patients (38.2%) had died. The 5-year event-free survival estimate was 54.2% (95% CI, 48.2% to 60.2%). In a multivariate analysis, disease stage, presenting signs of endocrine dysfunction, and age were independently associated with prognosis. CONCLUSION Childhood ACTs occur predominantly in females and almost always causes clinical signs. Complete resection is required for cure. Residual or metastatic disease carries a poor prognosis. Our results demonstrate the feasibility of a disease-specific database for obtaining meaningful clinical and outcome information.

Penetrance of adrenocortical tumours associated with the germline TP53 R337H mutation

Background: An inherited germline P53 mutation has been identified in cases of childhood adrenocortical carcinoma (ACT), a neoplasm with a high incidence in southern Brazil. The penetrance of ACT in carriers of the point mutation, which encodes an arginine-to-histidine substitution at codon 337 of TP53 (R337H), has not been determined. Objective: To investigate the penetrance of childhood ACT in carriers of the R337H TP53 mutation. Methods: The family histories of 30 kindreds of 41 southern Brazilian children with ACT were obtained. A PCR based assay was used to detect this P53 mutation in a large number of relatives of children with ACT. In all, 927 individuals were tested for the mutation, 232 from the non-carrier and 695 (including the 40 probands) from the carrier parental lines. Results: 40 children with ACT carried the TP53 R337H mutation; the remaining child with ACT was not tested. There was no evidence of Li-Fraumeni syndrome in any of the kindreds; however, seven met the criteria for Li-Fraumeni-like syndrome. The carrier parental line was identified in each kindred. Of the 695 individuals tested in the carrier parental line, 240 (34.5%) were positive for the mutation, while none of the 232 individuals in the other parental line carried the mutation. The penetrance of ACT was 9.9% (95% confidence interval, 8.7% to 11.1%). Conclusions: The TP53 R337H mutation dramatically increases predisposition to childhood ACT but not to other cancers, and explains the increased frequency of ACT observed in this geographic region.

Impact of Neonatal Screening and Surveillance for the TP53 R337H Mutation on Early Detection of Childhood Adrenocortical Tumors

PURPOSE The incidence of pediatric adrenocortical tumors (ACTs) is remarkably high in southern Brazil, where more than 90% of patients carry the germline TP53 mutation R337H. We assessed the impact of early detection of this mutation and of surveillance of carriers. PATIENTS AND METHODS Free newborn screening was offered at all hospitals in the state of Paraná. Parents of positive newborns were tested, and relatives in the carrier line were offered screening. Positive newborns and their relatives age < 15 years were offered surveillance (periodic clinical, laboratory, and ultrasound evaluations). ACTs detected by imaging were surgically resected. RESULTS Of 180,000 newborns offered screening, 171,649 were screened, and 461 (0.27%) were carriers. As of April 2012, ACTs had been diagnosed in 11 of these carriers but in only two neonatally screened noncarriers (P < .001); six patient cases were identified among 228 carrier relatives age < 15 years (total, 19 ACTs). Surveillance participants included 347 (49.6%) of 699 carriers. Tumors were smaller in surveillance participants (P < .001) and more advanced in nonparticipants (four with stage III disease; two deaths). Neonatally screened carriers also had neuroblastoma (n = 1), glioblastoma multiforme (n = 1), choroid plexus carcinoma (n = 2), and Burkitt lymphoma (n = 1). Cancer histories and pedigrees were obtained for 353 families that included 1,704 identified carriers. ACTs were the most frequent cancer among carrier children (n = 48). CONCLUSION These findings establish the prevalence of the TP53 R337H mutation in Paraná state and the penetrance of ACTs among carriers. Importantly, screening and surveillance of heterozygous carriers are effective in detecting ACTs when readily curable.

Adrenocortical tumors in children

Childhood adrenocortical tumors (ACT) are rare. In the USA, only about 25 new cases occur each year. In Southern Brazil, however, approximately 10 times that many cases are diagnosed each year. Most cases occur in the contiguous states of São Paulo and Paraná. The cause of this higher rate has not been identified. Familial genetic predisposition to cancer (p53 mutations) and selected genetic syndromes (Beckwith-Wiedemann syndrome) have been associated with childhood ACT in general but not with the Brazilian counterpart. Most of the affected children are young girls with classic endocrine syndromes (virilizing and/or Cushing). Levels of urinary 17-ketosteroids and plasma dehydroepiandrosterone sulfate (DHEA-S), which are abnormal in approximately 90% of the cases, provide the pivotal clue to a diagnosis of ACT. Typical imaging findings of pediatric ACT consist of a large, well-defined suprarenal tumor containing calcifications with a thin capsule and central necrosis or hemorrhage. The pathologic classification of pediatric ACT is troublesome. Even an experienced pathologist can find it difficult to differentiate carcinoma from adenoma. Surgery is the single most important procedure in the successful treatment of ACT. The role of chemotherapy in the management of childhood ACT has not been established although occasional tumors are responsive to mitotane or cisplatin-containing regimens. Because of the heterogeneity and rarity of the disease, prognostic factors have been difficult to establish in pediatric ACT. Patients with incomplete tumor resection or with metastatic disease at diagnosis have a dismal prognosis. In patients with localized and completely resected tumors, the size of the tumor has predictive value. Patients with large tumors have a much higher relapse rate than those with small tumors.

Biology, clinical characteristics, and management of adrenocortical tumors in children.

Childhood adrenocortical tumors (ACT) are very aggressive endocrine neoplasms whose incidence is quite low. Little is known about their pathogenesis, clinical presentation, and optimal treatment. In recent years, however, new information has been derived from the International Pediatric Adrenocortical Tumor Registry (IPACTR), and new clues to its pathogenesis have emerged. To provide an overview of the available data that may apply to pediatric ACT, we reviewed the epidemiology, pathogenesis, and treatment of ACT in adults and in children. Germline TP53 mutation is almost always the predisposing factor in childhood ACT. A unique germline mutation (TP53–R337H) has been described in Southern Brazil, where the incidence of ACT is 10–15 times the general incidence. Childhood ACT typically present during the first 5 years of life and has female predominance. Hormone hyperproduction is almost universal, and most patients present with virilization. Two‐thirds of patients have resectable tumors. Surgery is the definitive treatment for ACT, and a curative complete resection should always be attempted. Cisplatin‐based chemotherapy with mitotane is indicated for unresectable or metastatic disease, although its impact on overall outcome is slight. In childhood ACT, age, tumor size, and tumor resectability are the most important prognostic indicators. Outcome is stage‐dependent; patients with small, resectable tumors have survival rates in excess of 80%, whereas the outcome for patients with unresectable disease is dismal. Patients with large, resectable tumors have an intermediate outcome. Childhood ACT are rare, but their unique epidemiology appear to implicate novel oncogenic pathways that are unique to the pediatric population. Multi‐institutional and prospective studies are necessary to further our understanding of the pathogenesis and to improve outcomes.

Genomic landscape of paediatric adrenocortical tumours

Pediatric adrenocortical carcinoma is a rare malignancy with poor prognosis. Here we analyze 37 adrenocortical tumors (ACTs) by whole genome, whole exome and/or transcriptome sequencing. Most cases (91%) show loss of heterozygosity (LOH) of chromosome 11p, with uniform selection against the maternal chromosome. IGF2 on chromosome 11p is overexpressed in 100% of the tumors. TP53 mutations and chromosome 17 LOH with selection against wild-type TP53 are observed in 28 ACTs (76%). Chromosomes 11p and 17 undergo copy-neutral LOH early during tumorigenesis, suggesting tumor-driver events. Additional genetic alterations include recurrent somatic mutations in ATRX and CTNNB1 and integration of human herpesvirus-6 in chromosome 11p. A dismal outcome is predicted by concomitant TP53 and ATRX mutations and associated genomic abnormalities, including massive structural variations and frequent background mutations. Collectively, these findings demonstrate the nature, timing and potential prognostic significance of key genetic alterations in pediatric ACT and outline a hypothetical model of pediatric adrenocortical tumorigenesis.

Mortality rate of adrenocortical tumors in children under 15 years of age in Curitiba, Brazil†

Several reports refer to an increased frequency of adrenal cortex tumors (ACT) among children in Southern Brazil, yet all data have been derived from hospital‐based registries. An inherited germline mutation in the p53 gene (TP53 R337H) is detected in virtually all children with ACT in this region and accounts for the excess cases observed.

Increased Incidence of Choroid Plexus Carcinoma Due to the Germline TP53 R337H Mutation in Southern Brazil

Background Choroid plexus carcinomas (CPC) are rare tumors predominantly found in children. Given the high frequency of the germline R337H mutation in the TP53 gene in southern Brazil, we have evaluated the frequency of the R337H mutation in families with CPC in children. Methodology/Principal Findings The present series included 29 patients that were admitted to the same institution from 1992 to 2010, including 22 children with CPC (0.08–13.6 years of age at diagnosis) and 7 children with papilloma of the choroid plexus (Pp; 0.5–9.8 years of age). Surgical resection was possible in 28 children. Blood and/or tumor DNA was extracted and analyzed using PCR-RFLP and results were confirmed by sequencing 240 bp of the TP53 exon 10. The patients, all parents, and some relatives submitted samples for blood DNA analysis. In addition, we have also examined the presence of the mutation in DNA from paraffin-embedded tumor samples to evaluate loss of heterozygosity. We found 63.3% (14/22) of the CPC patients positive for the germline R337H mutation; CPC samples were either heterozygous (n = 7), lost only the wild-type (n = 4), or only the R337H copy (n = 2). One CPC sample was not available. All Pp cases (7/7, 100%) were negative for R337H. Cure (>5 years survival free of disease) was observed in 18.1% of the CPC cases with the R337H mutation (2/11), 71.4% of the Pp (5/7), and 25% of CPC cases negative for the R337H mutation (2/8). Family history of cancer (with 2 or more cancer cases) was exclusively identified on the parental side segregating the R337H mutation, and 50% (7/14) of them were compatible with Li-Fraumeni-like syndrome. Significance Our results show for the first time that the R337H TP53 mutation is responsible for 63% of the CPC cases in children, suggesting a higher incidence of CPC in southern Brazil.

Mitotane associated with cisplatin, etoposide, and doxorubicin in advanced childhood adrenocortical carcinoma: mitotane monitoring and tumor regression.

Purpose To define a mitotane dose for pediatric patients with adrenocortical cancer (ACC) that maintains therapeutic plasma levels (TL) between 14 and 20 μg/mL and to verify its antitumor efficacy in association with 8 cycles of cisplatin, etoposide, and doxorubicin (CED). Methods Powdered mitotane was dissolved in a medium chain triglyceride oil and administered to 11 children with ACC (2.4 to 15.4 y of age); an initial low dose was increased to 4 g/m2/d. Ten of the 11 children had a germline TP53 R337H mutation. Mitotane plasma levels were determined using high-performance liquid chromatography. Results The mitotane dose to maintain TL in 7 patients ranged from 1.0 to 5.3 g/m2/d. Six children reached mitotane levels of 10 μg/mL in 3.6 months (1.5 to 5.0 mo), whereas 5 children took 8 months (6.5 to 12.5 mo). Minor to partial tumor remission was found in 5 patients (<1 y) and complete remission was found in 2 patients. Of the 3 patients who are alive at the time of report, 1 patient has been without disease for 16 months, and 2 patients have progressive disease. All patients had recurrent metastatic disease (2 to 9 times). Mitotane toxic effects were nausea, diarrhea, vomiting, neurologic alterations, gynecomastia, a rare case of hypertensive encephalopathy, and CED-related hematologic toxic effects. Conclusions Mitotane daily dose to maintain TL is variable and monitoring should start 1.5 months after the beginning of treatment. CED combined with mitotane is the best available pharmacologic treatment for ACC, but further studies are required to characterize different profiles of therapeutic response.