Complex karyotype in a childhood adrenocortical carcinoma

Adrenocortical carcinoma in children: first population-based clinicopathological study with long-term follow-up

Adrenocortical carcinoma (ACC) is rare in both adult and pediatric populations. Literature suggests significant differences between children and adults in presentation, histological properties and outcome. The aim of this first nationwide study on pediatric ACC was to describe the incidence, presentation, pathological characteristics, treatment and survival in The Netherlands. All ACC patients aged <20 years at diagnosis and registered in the population-based Netherlands Cancer Registry between 1993 and 2010 were included. Clinical data were extracted from medical records. Archival histological slides were collected via the Dutch Pathology Registry (PALGA). We compared our findings to all clinical studies on pediatric ACC that were found on PubMed. Based on the results, 12 patients were identified: 8 females and 4 males. The median age was 4.1 years (range 1.1-18.6). The population-based age-standardized incidence rate for patients <20 years was 0.18 per million person-years. Autonomous hormonal secretion was present in 10 patients. Seven patients were aged ≤4 years at diagnosis, 5 presented with localized disease and 2 with locally advanced disease. Five patients were aged ≥5 years, 3 presented with distant metastases and 1 with locally advanced disease. For all patients, histological examination displayed malignant characteristics. All patients aged ≤4 years at diagnosis survived; the median follow-up was 97 months (57-179 months). All patients aged ≥5 years died; the median survival was 6 months (0-38 months). Pediatric ACC is extremely rare in the Western world. The clinical outcome was remarkably better in patients aged ≤4 years. This is in accordance with less advanced stage of disease at presentation, yet contrasts with the presence of adverse histological characteristics. Clinical management in advanced disease is adapted from adult practice in the absence of evidence regarding pediatric ACC.

Genomic and expression profiling of adrenocortical carcinoma: application to diagnosis, prognosis and treatment

Adrenocortical carcinoma (ACC) is an aggressive endocrine tumor with a poor 5-year survival rate of 10–20%. Current therapy is often ineffective and may be associated with intolerable side effects. Although ACC is extremely rare, recent advances in genomic and expression profiling, coupled with knowledge gained from the study of the inherited syndromes that increase ACC risk, are beginning to bring together a picture of a tumor type dependent on p53, the G2/M cell cycle transition and IGF2 stimulation. Nevertheless, ACC remains a heterogeneous disease. Only recently have sufficient tumors been characterized and results published to permit an exploration of this diversity. Advances in treatment will depend on exploiting those pathways already implicated in ACC, along with those yet to be identified, and testing those treatments in better models of the disease than the three cell lines that currently exist and are widely available to the community.

[Molecular mechanisms involved in adrenocortical tumorigenesis]

The adrenocortical tumorigenesis is a complex process, which involves multiple genetic changes. A better knowledge on the mechanisms involved in tumor development would enable an early identification of malignant disease and also lead to the development of new treatment strategies. Although in the recent years a large amount of data was produced, the exact mechanisms that lead to adrenocortical tumor development remains poorly understood. Most of the studies produced were based on the candidate-gene strategy, which has its own limitations. A genome-wide approach, such as microarrays, will surely shed some light into the mechanisms responsible for adrenocortical tumorigenesis. In this review, we summarize the most recent data available on this complex process.

Distinct transcriptional profiles of adrenocortical tumors uncovered by DNA microarray analysis

Comprehensive expression profiling of tumors using DNA microarrays has been used recently for molecular classification and biomarker discovery, as well as a tool to identify and investigate genes involved in tumorigenesis. Application of this approach to a cohort of benign and malignant adrenocortical tissues would be potentially informative in all of these aspects. In this study, we generated transcriptional profiles of 11 adrenocortical carcinomas (ACCs), 4 adrenocortical adenomas (ACAs), 3 normal adrenal cortices (NCs), and 1 macronodular hyperplasia (MNH) using Affymetrix HG_U95Av2 oligonucleotide arrays representing approximately 10,500 unique genes. The expression data set was used for unsupervised hierarchical cluster analysis as well as principal component analysis to visually represent the expression data. An analysis of variance on the three classes (NC, ACA plus MNH, and ACC) revealed 91 genes that displayed at least threefold differential expression between the ACC cohort and both the NC and ACA cohorts at a significance level of P < 0.01. Included in these 91 genes were those known to be up-regulated in adrenocortical tumors, such as insulin-like growth factor (IGF2), as well as novel differentially expressed genes such as osteopontin (SPP) and serine threonine kinase 15 (STK15). Increased expression of IGF2 was identified in 10 of 11 ACCs (90.9%) and was verified by quantitative reverse transcriptase-polymerase chain reaction. Select proliferation-related genes (TOP2A and Ki-67) were validated at the protein level using immunohistochemistry and adrenocortical tissue microarrays. Our results demonstrated significant and consistent gene expression changes in ACCs compared to benign adrenocortical lesions. Moreover, we identified several genes that represent potential diagnostic markers and may play a role in the pathogenesis of ACC.

Genetic background of adrenocortical tumor development

The increasing occurrence of incidentally discovered benign adrenocortical tumors has become a clinical dilemma because of the difficulties in differentiating them from their malignant counterpart. Adrenocortical tumors are associated with familial cancer syndromes such as the Beckwith-Wiedemann syndrome, the Li-Fraumeni syndrome, the Carney complex, multiple endocrine neoplasia type 1, congenital adrenal hyperplasia, and the McCune-Albright syndrome. Genetic events are known to take place on the chromosomal and gene level in sporadic adrenocortical tumors.

Adrenocortical carcinoma in children. Review and recent innovations

Adrenocortical carcinoma in childhood is a rare potentially fatal disease. Despite its often dramatic presentation, there typically has been a distressingly long delay between the onset of symptoms and the time of diagnosis. This delay undoubtedly has contributed to the historically poor prognosis in these children by permitting the disease to reach an advanced stage before treatment is started. It is imperative that the physician recognizes the endocrine manifestations of these tumors early and has a high index of suspicion. Although biochemical and histologic evaluations are helpful, they often cannot differentiate benign lesions from malignant neoplasms and should not unduly delay intervention. Aggressive complete surgical resection continues to be the mainstay of treatment and is the best prognosticator of overall survival. The role of adjuvant therapy and chemotherapy continues to evolve. Molecular studies have increased understanding of cancer biology and may provide possible novel therapeutic approaches in the future. It is hoped that increased familiarity with this unusual tumor will result in earlier detection, prompt intervention, and improved survival for children with adrenocortical carcinoma.