Percentage tumor necrosis following chemotherapy in neuroblastoma correlates with MYCN status but not survival

The Role of Chronic Inflammation in Pediatric Cancer

Inflammation plays a crucial role in wound healing and the host immune response following pathogenic invasion. However, unresolved chronic inflammation can result in tissue fibrosis and genetic alterations that contribute to the pathogenesis of human diseases such as cancer. Recent scientific advancements exploring the underlying mechanisms of malignant cellular transformations and cancer progression have exposed significant disparities between pediatric and adult-onset cancers. For instance, pediatric cancers tend to have lower mutational burdens and arise in actively developing tissues, where cell-cycle dysregulation leads to gene, chromosomal, and fusion gene development not seen in adult-onset counterparts. As such, scientific findings in adult cancers cannot be directly applied to pediatric cancers, where unique mutations and inherent etiologies remain poorly understood. Here, we review the role of chronic inflammation in processes of genetic and chromosomal instability, the tumor microenvironment, and immune response that result in pediatric tumorigenesis transformation and explore current and developing therapeutic interventions to maintain and/or restore inflammatory homeostasis.

Clinical impact of primary tumour 123ImIBG response to induction chemotherapy in children with high-risk neuroblastoma

BACKGROUND

More than 50% children with high-risk neuroblastoma (HR-NBL) experience disease progression, which we hypothesise is due to non-response of primary tumour to treatment. Current imaging techniques are unable to characterise response in primary tumour (necrotic versus viable tissue) at diagnosis or follow-up.

OBJECTIVES

Compare clinico-histological characteristics between primary ¹²³ImIBG-avid tumours that became entirely ¹²³ImIBG-non-avid (responders) after induction chemotherapy (IC) versus primary ¹²³ImIBG-avid tumour that remained ¹²³ImIBG-avid (non-responders).

METHODS

Retrospective review of clinico-radiological data of children diagnosed with ¹²³ImIBG-avid HR-NBL at our centre (2005-2016). Patients received Rapid COJEC IC and two additional courses of TVD if metastatic response was inadequate. Primary tumour ¹²³ImIBG response was assessed qualitatively as positive, negative or intermediate at diagnosis and after IC. Post-surgical histopathology slices were marked considering percentage of viable tissue.

RESULTS

Sixteen of 61 patients showed complete primary tumour ¹²³ImIBG response, 20 partial response, while 25 no response. There was no statistically significant difference between clinical demographics of complete responders and group of non- or partial responders. Mean percentage of viable tumour cells was higher in non-responders than in complete responders (44.6% vs 20.6%; p = 0.05). Five-year EFS was significantly higher in complete responders than non-responders (43 ± 15% vs 7 ± 6%; p < 0.005).

CONCLUSIONS

¹²³ImIBG response in primary HR-NBL correlates with amount of necrotic tissue, skeletal metastatic ¹²³ImIBG response and outcome. An entirely ¹²³ImIBG non-avid tumour can still harbour viable tumour cells. Therefore, our findings do not support utility of primary tumour ¹²³ImIBG response in decision making regarding residual tumour surgery. Combining both, primary and metastatic ¹²³ImIBG response will improve interpretability of clinical trial results.

5-aza-2'-Deoxycytidine Induces a RIG-I-Related Innate Immune Response by Modulating Mitochondria Stress in Neuroblastoma

Background: Neuroblastoma (NB) is one of the most common malignant solid tumors to occur in children, characterized by a wide range of genetic and epigenetic aberrations. We studied whether modifications of the latter with a 5-aza-2′-deoxycytidine (decitabine, Dac) DNA methyltransferase inhibitor can provide a therapeutic advantage in NB. Methods: NB cells with or without MYCN amplification were treated with Dac. We used flow cytometry to measure cell apoptosis and death and mitochondrial reactive oxygen species (mtROS), microarray to analyze gene expression profile and bisulfite pyrosequencing to determine the methylation level of the DDX58/RIG-I promoter. Western blot was used to detect markers related to innate immune response and apoptotic signaling, while immunofluorescent imaging was used to determine dsRNA. We generated mtDNA depleted ρ⁰ cells using long-term exposure to low-dose ethidium bromide. Results: Dac preferentially induced a RIG-I-predominant innate immune response and cell apoptosis in SK-N-AS NB cells, significantly reduced the methylation level of the DDX58/RIG-I promoter and increased dsRNA accumulation in the cytosol. Dac down regulated mitochondrial genes related to redox homeostasis, but augmented mtROS production. ρ⁰ cells demonstrated a blunted response in innate immune response and apoptotic cell death, as well as greatly diminished dsRNA. The response of NB cells to CDDP and poly(I:C) was potentiated by Dac in association with increased mtROS, which was blunted in ρ⁰ cells. Conclusions: This study indicates that Dac effectively induces a RIG-I-related innate immune response and apoptotic signaling primarily in SK-N-AS NB cells by hypomethylating DDX58/RIG-I promoter, elevated mtROS and increased dsRNA. Dac can potentiate the cytotoxic effects of CDDP and poly(I:C) in NB cells.

Effects of preoperative chemotherapy on neuroblastoma with MYCN amplification: a surgeon’s perspective

Background

Preoperative chemotherapy plays an important role in the surgical management of unresectable neuroblastoma. Its response to chemotherapy has been variable due to the tumor’s heterogeneity. We aimed to evaluate the effects of preoperative chemotherapy on MYCN-amplified (MYCNA) neuroblastoma that would impact on surgical resection.

Methods

Patients with MYCNA neuroblastoma who received preoperative chemotherapy followed by surgical resection performed at our center were included. The tools of response evaluated included tumor volume reduction (TVR), reduction in image-defined risk factors (IDRFs), percentage tumor necrosis (Nec), and surgical complications.

Results

Among 62 patients evaluated, mean age was 3.0 (range, 0.9–11.8) years, and primary tumors were distributed in the abdomen (n=59), pelvis (n=2), and thorax (n=1). The patients were in stages L2 (n=14) and M (n=48). Surgery was performed after median of 4 (range, 2–10) cycles of chemotherapy. On completion of preoperative chemotherapy, 41 (66.1%) patients had TVR >65%, 24 (42.9%) responded with reduced IDRFs, 47 (75.8%) tumors had Nec >50%, and 27 patients suffered 31 surgical complications. Majority (83.9%) continued to have IDRFs at surgery. IDRFs commonly encountered were encasement of renal pedicles (n=50), superior mesenteric artery (n=46), celiac axis (n=45), and aorta/vena cava (n=44), and most remained refractory to resolution. Patients with TVR >65% were associated with Nec >50% (87.5% vs 54.5%, p=0.004) and reduced IDRFs (46.3% vs 19%, p=0.035), but not with the incidence of surgical complications.

Conclusions

Majority of MYCNA neuroblastomas were highly chemosensitive as they experienced high TVR, reduced IDRFs, and high Nec, and hence created favorable conditions for surgical resection. Poor responders and persistent IDRFs that were commonly refractory to preoperative chemotherapy remained a surgical challenge.

Predictors of differential response to induction therapy in high-risk neuroblastoma: A report from the Children's Oncology Group (COG)

BACKGROUND

Induction chemotherapy plays an important role in the management of patients with high-risk neuroblastoma. Predictors of response to induction therapy are largely lacking. We sought to describe clinical and biological features associated with induction response.

METHODS

Patients from four consecutive COG high-risk trials were included. Response was evaluated by the 1993 International Neuroblastoma Response Criteria. The primary end-point was end-induction partial response (PR) or better. Univariate analyses were performed to compare response as a function of clinical or biologic predictors. A multivariate logistic regression model using significant predictors from univariate analyses was constructed to model PR or better.

RESULTS

The analytic cohort included 1242 patients. End-induction response ≥PR was significantly associated with higher event-free and overall survival. Baseline factors associated with ≥PR included age <18 months (87.4% with ≥PR vs. 78.7% if older; p = 0.0103), International Neuroblastoma Staging System non-stage 4 (89.0% vs. 78.4% if stage 4; p = 0.0016), MYCN amplification (85.5% vs. 77.1% if non-amplified; p = 0.0006), 1p loss of heterozygosity (LOH; 85.6% vs. 76.0% if no LOH; p = 0.0085), no 11q LOH (84.8% vs. 70.9% if 11q LOH; p = 0.0004) and high mitosis-karyorrhexis index (MKI; 84.5% vs. 77.5% if low-intermediate MKI; p = 0.0098). On multivariable analysis (n = 407), the absence of 11q LOH was the only factor that remained significantly associated with ≥PR (odds ratio: 1.962 vs. 11q LOH; 95% confidence interval 1.104-3.487; p = 0.0216).

CONCLUSIONS

Improved end-induction response in high-risk neuroblastoma is associated with longer survival. Patients with 11q LOH are less likely to respond to induction therapies and should be prioritised for novel approaches in future trials.

Tumor histopathological response to neoadjuvant chemotherapy in childhood solid malignancies: is it still impressive?

The management of oncological malignancies has significantly improved over the last decades. In modern medicine, new concepts and trends have emerged paving the way for the era of personalized and evidence-based strategies adapted to the patients’ prognostic variables and requirements. Several challenges do exist that are encountered during the management, including the difficulty to assess chemotherapy response with certainty. Having known that neoadjuvant chemotherapy might be the only solution for a proportion of patients with tumors that are unresectable at diagnosis, emergence of strategies that use risk group-directed therapy became an integral part in the management of oncological malignancies. Tumor histopathological change post neoadjuvant chemotherapy is one of the most important predictors of management outcome and is being used in many chemotherapy protocols as an essential determinant of the most suitable postoperative chemotherapy regimen. Bone tumors are the classic models of this approach; however, other childhood solid tumors show significant variations in outcome as a result of tumor histopathological response to neoadjuvant chemotherapy. The aim of this review is therefore to summarize the significance of histopathological responses seen after neoadjuvant chemotherapy in childhood solid tumors. Moreover, it suggests that the effect on tumor histopathology through modifying neoadjuvant chemotherapy and, on the other hand, toxicities from intensifying adjuvant chemotherapy might either necessitate the change of a number of arm groups in different protocol regimens or include newer chemotherapeutic agents adjuvantly for better outcome and lesser toxicities in poor tumor histopathological responders.

Heterogeneity of MYCN amplification in neuroblastoma at diagnosis, treatment, relapse, and metastasis

Amplification of the MYCN gene in neuroblastoma is associated with a poor prognosis and is considered to remain unchanged in post-treatment specimens and metastases. While heterogeneity of MYCN copy number in tumor cells has been reported, serial samples have only been studied in a limited way, and the biologic relevance of this finding is not well understood. We used in situ hybridization on paraffin sections of 102 specimens from 30 patients with MYCN-amplified neuroblastoma to determine MYCN copy number in the primary tumor, pre- and post-treatment, and in metastatic samples. Nineteen cases (63%) showed diffuse MYCN amplification in all samples tested. Nine cases (30%) showed a reduction in MYCN copy number: five cases with diffuse amplification subsequently showed focal amplification, one case with diffuse MYCN amplification showed MYCN gain after treatment, and three focally amplified cases were non-amplified in later specimens. In two cases (7%), focal amplification became diffuse in subsequent samples. Histology was not predictive of the temporal or spatial pattern of MYCN amplification for a particular tumor. If extent of amplification (focal vs. diffuse) is not considered, 26/30 (87%) of cases were consistently MYCN-amplified. However, our data suggest that MYCN status can be heterogeneous between tumor sites, during tumor progression or following treatment, challenging the notion that MYCN copy number does not change for a particular neuroblastoma. Assessing the biologic significance of MYCN heterogeneity will require larger studies of clinically annotated tumor samples, and will depend on interpreting heterogeneity in MYCN status in combination with other genetic changes. © 2016 Wiley Periodicals, Inc.

Rapid COJEC versus standard induction therapies for high-risk neuroblastoma

BACKGROUND

Neuroblastoma is a rare malignant disease and mainly affects infants and very young children. The tumors mainly develop in the adrenal medullary tissue and an abdominal mass is the most common presentation. The high-risk group is characterized by metastasis and other characteristics that increase the risk for an adverse outcome. In the rapid COJEC induction schedule, higher single doses of selected drugs than standard induction schedules are administered over a substantially shorter treatment period, with shorter intervals between cycles. Shorter intervals and higher doses increase the dose intensity of chemotherapy and might improve survival.

OBJECTIVES

The aim of this study was to evaluate the efficacy and adverse events of the rapid COJEC induction schedule as compared to standard induction schedules in patients with high-risk neuroblastoma (as defined by the International Neuroblastoma Risk Group (INRG) classification system). Outcomes of interest were complete response, early toxicity and treatment-related mortality as primary endpoints and overall survival, progression- and event-free survival, late non-hematological toxicity, and health-related quality of life as secondary endpoints.

SEARCH METHODS

We searched the electronic databases CENTRAL (2014, Issue 11), MEDLINE (PubMed), and EMBASE (Ovid) for articles from inception to 11 November 2014. Further searches included trial registries, conference proceedings, and reference lists of recent reviews and relevant articles. We did not apply limits on publication year or languages.

SELECTION CRITERIA

Randomized controlled trials evaluating the rapid COJEC induction schedule for high-risk neuroblastoma patients compared to standard induction schedules.

DATA COLLECTION AND ANALYSIS

Two review authors performed study selection, abstracted data on study and patient characteristics, and assessed risk of bias independently. We resolved differences by discussion or by appeal to a third review author. We performed analyses according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions. We used the five GRADE considerations, study limitations, consistency of effect, imprecision, indirectness, and publication bias, to judge the quality of the evidence. We downgraded for risk of bias and imprecision

MAIN RESULTS

We identified one randomized controlled trial (CCLG-ENSG-5) that included 262 patients with high-risk neuroblastoma who were randomized to receive either rapid COJEC (N = 130) or standard OPEC/COJEC (N = 132) induction chemotherapy. We graded the evidence as low quality; we downgraded for risk of bias and imprecision.There was no clear evidence of a difference between the treatment groups in complete response (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.71 to 1.38), treatment-related mortality (RR 1.21, 95% CI 0.33 to 4.39), overall survival (hazard ratio (HR) 0.83, 95% CI 0.63 to 1.10), and event-free survival (HR 0.86, 95% CI 0.65 to 1.13). We calculated the HRs using the complete follow-up period of the trial.Febrile neutropenia (two or more episodes), proven fungal infections, septicemia (one or more episodes), gastrointestinal toxicity (grade 3 or 4), renal toxicity (glomerular filtration rate < 80 ml/min per body surface area of 1.73 m(2)), neurological toxicity (grade 3 or 4), and ototoxicity (Brock grade 2 to 4) were addressed as early toxicities (during pre-operative chemotherapy). For febrile neutropenia, septicemia, and renal toxicity, a statistically significant difference in favor of the standard treatment arm was identified; for all other early toxicities no clear evidence of a difference between treatment groups was identified. With regard to late non-hematological toxicities (median follow-up 12.7 years; range 6.9 to 16.5 years), the study provided data on any complication, renal toxicity (glomerular filtration rate < 80 ml/min per body surface area of 1.73m(2)), ototoxicity (Brock grade 1 to 4), endocrine complications, neurocognitive complications (i.e. behavioral, speech, or learning difficulties), and second malignancies. For endocrine complications and neurocognitive complications, a statistically significant difference in favor of the rapid COJEC arm was found; for all other late non-hematological toxicities no clear evidence of a difference between treatment groups was identified.Data on progression-free survival and health-related quality of life were not reported.

AUTHORS' CONCLUSIONS

We identified one randomized controlled trial that evaluated rapid COJEC versus standard induction therapy in patients with high-risk neuroblastoma. No clear evidence of a difference in complete response, treatment-related mortality, overall survival, and event-free survival between the treatment alternatives was found. This could be the result of low power or too short a follow-up period. Results of both early and late toxicities were ambiguous. Information on progression-free survival and health-related quality of life were not available. This trial was performed in the 1990s. Since then, many changes in, for example, treatment and risk classification have occurred. Therefore, based on the currently available evidence, we are uncertain about the effects of rapid COJEC and standard induction therapy in patients with high-risk neuroblastoma. More research is needed for a definitive conclusion.

Histological features of primary tumors after induction or high-dose chemotherapy in high-risk neuroblastoma

PURPOSE

In the recent years in Japan, an increasing number of patients with neuroblastoma (NB) are being treated by the "delayed local treatment (DL)" policy, undergoing surgery after the completion of high-dose chemotherapy with hematopoietic stem cell rescue (HDC). We reviewed the histopathological findings of second-look operations, including those of patients treated with DL.

PATIENTS

From 1998 to 2013, 26 patients with high-risk NB underwent radical operation following chemotherapy. Surgery was performed after induction chemotherapy in 17 cases (standard; STD), whereas 9 cases completed induction chemotherapy and HDC before undergoing tumor resection (DL). The amount of necrosis and the degree of differentiation within the post-treatment tumor were assessed.

RESULTS

Eighty-eight percent of the tumors showed necrosis in more than 1/3 of the specimen. Two DL cases showed complete disappearance of viable tumor cells. Amount of necrosis did not affect the prognosis of the patient. Tumors with immature, poorly differentiated phenotypes showed an extremely aggressive thereafter. Though not statistically proven, (123)I-MIBG (metaiodobenzylguanidine) uptake may be correlated with the amount of viable cells remaining within the tumor, but not with the degree of differentiation.

CONCLUSIONS

Our results support the previous reports advocating that tumors that sustain unfavorable histology after chemotherapy behave aggressively thereafter.

Tumor histology during induction therapy in patients with high-risk neuroblastoma

BACKGROUND

In high-risk neuroblastoma patients, response to induction chemotherapy is emerging as an important determinant of overall survival. We sought to determine whether histological changes in the primary tumor following induction therapy could be used as a marker of response.

PROCEDURE

Second-look primary tumor specimens from 43 patients were reviewed according to specific morphological features.

RESULTS

In the majority, induction therapy resulted in a shift from an intermediate/high to low mitosis-karyorrhexis index (MKI) (P = 0.0009) and from undifferentiated/poorly differentiated to differentiating tumors (P < 0.0001). Following induction therapy, persistence of intermediate/high tumor MKI and ≥90% persistent neuroblastic cells were predictive of a poor outcome (P = 0.001 and 0.03, respectively). Less than 10% tumor necrosis was associated with a trend towards lower survival.

CONCLUSIONS

High proliferative activity in the primary tumor following induction therapy portends a poor outcome in patients with high-risk neuroblastoma. If confirmed in a larger cohort, tumor histology at second-look surgery could be used to define a subset of very high risk patients who would benefit from alternative therapies prior to myeloablative dose-intensive transplant.