Metastatic neuroblastoma after 52 years of dormancy

Cancer Stem Cells and Neuroblastoma: Characteristics and Therapeutic Targeting Options

The majority of embryonal tumors or childhood blastomas derive from pluripotent progenitors or fetal stem cells that acquire cancer stem cell (CSC) properties: multipotency, self-renewal ability, metastatic potential, chemoresistance, more pronounced levels of drug transporters, enhanced DNA-damage repair mechanisms, and a quiescent state. Neuroblastoma (NB) is considered a neuroendocrine tumor and is the most common extracranial neoplasm in children. NB pathogenesis has frequently been associated with epigenetic dysregulation and a failure to implement a differentiation program. The origin, characteristics, and isolation of the CSC subpopulation in NB are still incompletely understood, despite the evidence that this cell subset contributes to disease recurrence and acquired resistance to standard therapies. Here, we summarize the literature regarding the isolation and characterization of CSCs in NB over the past decades, from the early recognition of the expression of stem cell factor (SCF) or its receptor c-KIT to more recent studies identifying the ability of G-CSF and STAT3 to support stem cell-like properties in NB cells. Additionally, we review the morphological variants of NB tumors whose recent epigenetic analyses have shed light on the tumor heterogeneity so common in NB. NB-derived mesenchymal stem cells have recently been isolated from primary tumors of NB patients and associated with a pro-tumorigenic role in the tumor microenvironment, enabling immune escape by tumors, and contributing to their invasive and metastatic capabilities. In particular, we will focus on epigenetic reprogramming in the CSC subpopulation in NB and strategies to target CSCs in NB.

Protracted dormancy of pre-leukemic stem cells

Cancer stem cells can escape therapeutic killing by adopting a quiescent or dormant state. The reversibility of this condition provides the potential for later recurrence or relapse, potentially many years later. We describe the genomics of a rare case of childhood BCR-ABL1-positive, B-cell precursor acute lymphoblastic leukemia that relapsed, with an acute myeloblastic leukemia immunophenotype, 22 years after the initial diagnosis, sustained remission and presumed cure. The primary and relapsed leukemias shared the identical BCR-ABL1 fusion genomic sequence and two identical immunoglobulin gene rearrangements, indicating that the relapse was a derivative of the founding clone. All other mutational changes (single-nucleotide variant and copy number alterations) were distinct in diagnostic or relapse samples. These data provide unambiguous evidence that leukemia-propagating cells, most probably pre-leukemic stem cells, can remain covert and silent but potentially reactivatable for more than two decades.

Clinical appearance of neuroblastoma 10 years after screening

A follow-up study was performed for children with previous repeated positive results by neuroblastoma mass screening and negative clinical results (30 out of 439,128 children screened in Austria between 1991 and 2003, median follow-up 113 months). Four children had continuously elevated urine catecholamines for more than 6 months. One of these patients was diagnosed with pelvic neuroblastoma and multiple metastases 10 years after the first positive screening result. In the light of a 'wait and see' strategy for localized neuroblastomas, our observation suggests that these patients should be further observed even after normalization of urine catecholamines.

Late relapse and prognosis for neuroblastoma patients surviving 5 years or more: a report from the European Neuroblastoma Study Group "Survey"

BACKGROUND AND PROCEDURE

Most deaths from neuroblastoma occur within 2 years of diagnosis but there have been several anecdotal reports of relapse and death after much longer periods of follow up. In order to investigate and quantify the risk of late events we analysed data for patients registered with the European Neuroblastoma Study Group between 1982 and 1990. Out of a total of 1,277 children registered, 427 were alive with follow-up beyond 5 years from diagnosis (median follow-up of 8.8 years, range 5-14 years). Of these 406 were in remission with no prior recurrence, 16 were in remission having experienced a relapse prior to 5 years, and 5 were alive with progressive disease.

RESULTS

For the 406 patients in remission with no prior relapse the 10 year progression free survival (PFS) was 96% (CI 94-98). For those aged over 1 year with stage 4 disease at diagnosis 10 year PFS was 88% (CI 79-96) compared to 98% (CI 97-99) for other patients combined, P< 0.001. In a multivariate analysis of all 422 patients in remission at 5 years, significant risk factors for subsequent relapse were age > 1 yr with stage 4 disease at diagnosis (relative risk 10.5, P < 0.001) and prior relapse (RR 4.2, P= 0.01).

CONCLUSIONS

The results of this study emphasise the importance of longterm follow-up of patients and the need for late monitoring of clinical trials in children with neuroblastoma. They also provide a baseline for comparison with future and hopefully more effective treatment programmes.

Clinicopathologic study of mass-screened neuroblastoma with special emphasis on untreated observed cases: a possible histologic clue to tumor regression

Spontaneous regression and maturation of neuroblastoma (NB) are well documented and occur frequently in infants, including those detected by mass screening. To seek histologic clues for regression/maturation in mass-screened NB, clinicopathologic features of 12 tumors that were resected after 2 to 18 months of untreated observation were reviewed. Unobserved screened and age-matched unscreened patients were also studied. To evaluate the possible important role of apoptosis, apoptotic cells were detected by in situ deoxyribonucleic acid (DNA) nick end labeling and immunohistochemical stain for activated caspase-3. Nests with a varying degree of reduced cellularity ("less cellular" and "hypocellular" nests) were common in patients younger than 18 months of age, and were rare in older patients. Two characteristic cells, which have not been focused previously, were frequent, especially in the hypocellular nests. One showed amorphic eosinophilic cytoplasm with pyknotic nuclei and the other contained plump cytoplasm with well-maintained nuclei. These cells were also observed in 89% of the unobserved screened NBs and 79% of the age-matched unscreened patients with good outcome, whereas they could not be confirmed in any of the age-matched unscreened NBs with poor outcome. The amorphic and plump cells were negative for activated caspase-3 and in situ DNA nick end labeling. From these results, the authors hypothesize that these cells most likely represent a degenerative process, in either a state before the activation of caspase-3 or a caspase-independent form of cell death. The presence of less cellular and hypocellular nests with amorphic/plump cells may serve as one of the important clues in predicting tumor prognosis.

Neuroblastoma and other childhood neural tumors: a review

Neuroblastoma is the most common nonhematopoietic solid tumor of childhood and has been intensively studied for at least 4 decades. Despite this, few predictive histopathologic clues to its behavior exist. Age, anatomic sites of occurrence, and clinical stage have traditionally been the only reliable prognostic factors in this disease. A number of laboratory studies that focus on biologic features such as neurotransmitter synthesis (adrenergic and noradrenergic catecholamines), neurotransmitter enzyme expression (dopamine beta hydroxylase, choline acetyl transferase), cytogenetics (homogeneously staining regions, double minute chromosomes, chromosome 1p deletions), molecular genetics (N-myc oncogene amplification and expression), and immunophenotype (surface epitopes such as HLA antigens and GD2 ganglioside and intracytoplasmic determinants such as neurofilament protein, synaptophysin, chromogranin, and neuron specific enolase) now enable the pathologist to predict clinical course in many cases and to distinguish bona fide neuroblastomas, regardless of age, site, or histologic appearance, from a host of related but distinctly separate neuroectodermal tumor entities with apparent different histogenesis, treatment sensitivity, and prognosis.

Late recurrence of neuroblastoma: a report of five cases and review of the literature

Late recurrence of neuroblastoma is uncommon. We report five patients who developed recurrent disease more than five years after diagnosis and review the literature on this subject.

Treatment results among adults with childhood tumors: a 20-year experience

Controversy exists regarding the most appropriate treatment for the rare adult patient who develops a so-called pediatric cancer. We have reviewed our 20-year experience with these patients and analyzed their outcome. A total of 299 patients with rhabdomyosarcoma (106), Wilms' tumor (97), and neuroblastoma (96) were evaluated and treated at Stanford University Medical Center between January 1967 and December 1987. Only 26 of these patients (8.7%) were diagnosed during "adulthood"; their age range was 18-67 years, median 23 years. Wilms' tumor; Five patients presented with Wilms' tumor at age greater than or equal to 18 years; four had unfavorable histology. All underwent multimodality therapy; however, only two have survived, one currently disease-free and one with disease. Neuroblastoma: Five patients presented with neuroblastoma at age greater than or equal to 18 years. Four underwent attempted surgical resection, post-operative irradiation (RT), and chemotherapy (CT); the other received no adjuvant CT. Only two of the five patients survive, both with disease. Rhabdomyosarcoma: Of the 16 adults (greater than or equal to 21 years) with rhabdomyosarcoma, 14 (87%) had advanced Intergroup Rhabdomyosarcoma Study-group disease (eight Group III, six Group IV). All 16 underwent aggressive multimodality therapy. At 10 months-16 years follow-up, only five patients survive, four of whom are apparently cured of their tumor. Neither histologic subtype nor site of presentation were of prognostic value. This series demonstrates that adults with Wilms' tumor, neuroblastoma, or rhabdomyosarcoma have a worse prognosis than do children with the same diagnosis. Possible explanations for this disparity in outcome include different tumor biology, less tolerance for treatment, and different natural history among adults relative to children.