A prospective study of a long-term follow-up of an observation program for neuroblastoma detected by mass screening

Health Insurance Coverage and Racial/Ethnic Disparities in U.S. Childhood and Adolescent Cancer Survival

OBJECTIVE

To evaluate potential effect modification by health insurance coverage on racial and ethnic disparities in cancer survival among U.S. children and adolescents.

STUDY DESIGN

Data from 54,558 individuals diagnosed with cancer at ≤ 19 years between 2004 and 2010 were obtained from the National Cancer Database. Cox proportional hazards regression was used for analyses. An interaction term between race/ethnicity and health insurance type was included to examine racial/ethnic disparities in survival by each insurance status category.

RESULTS

Racial/ethnic minorities experienced a 14-42% higher hazard of death compared with non-Hispanic Whites with magnitudes varying by health insurance type (P_interaction < 0.001). Specifically, among those reported as privately insured, the hazard of death was higher for non-Hispanic Blacks (hazard ratio [HR]=1.48, 95% confidence interval [CI]: 1.36-1.62), non-Hispanic American Indian/Alaskan Natives (HR=1.30, 95%CI: 1.13-1.50), non-Hispanic Asians or Pacific Islanders (HR=1.99, 95%CI: 1.36-2.90) and Hispanics (HR=1.28, 95%CI: 1.17-1.40) vs. non-Hispanic Whites. Racial/ethnic disparities in survival among those reported as covered by Medicaid were present for non-Hispanic Blacks (HR=1.30, 95%CI: 1.19-1.43) but no other racial/ethnic minorities (HR ranges: 0.98∼1.00) vs. non-Hispanic Whites. In the uninsured group, the hazard of death for non-Hispanic Blacks (HR=1.68, 95%CI: 1.26-2.23) and Hispanics (HR=1.27, 95%CI: 1.01-1.61) was higher vs. non-Hispanic Whites.

CONCLUSIONS

Disparities in survival exist across insurance types, particularly for non-Hispanic Black childhood and adolescent cancer patients vs. non-Hispanic Whites with private insurance. These findings provide insights for research and policy and point to the need for more efforts on promoting health equity while improving health insurance coverage.

Alterations in ALK/ROS1/NTRK/MET drive a group of infantile hemispheric gliomas

Infant gliomas have paradoxical clinical behavior compared to those in children and adults: low-grade tumors have a higher mortality rate, while high-grade tumors have a better outcome. However, we have little understanding of their biology and therefore cannot explain this behavior nor what constitutes optimal clinical management. Here we report a comprehensive genetic analysis of an international cohort of clinically annotated infant gliomas, revealing 3 clinical subgroups. Group 1 tumors arise in the cerebral hemispheres and harbor alterations in the receptor tyrosine kinases ALK, ROS1, NTRK and MET. These are typically single-events and confer an intermediate outcome. Groups 2 and 3 gliomas harbor RAS/MAPK pathway mutations and arise in the hemispheres and midline, respectively. Group 2 tumors have excellent long-term survival, while group 3 tumors progress rapidly and do not respond well to chemoradiation. We conclude that infant gliomas comprise 3 subgroups, justifying the need for specialized therapeutic strategies.

Infant gliomas behave differently to their childhood or adult counterparts. Here, the authors perform a large-scale genetic analysis of these tumours, revealing genetic alterations which may offer therapeutic opportunities.

Excellent prognosis of patients with intermediate-risk neuroblastoma and residual tumor postchemotherapy

BACKGROUND/PURPOSE

The prognosis of patients with intermediate-risk neuroblastoma is favorable; therefore, a reduction therapy is desired. However, the long-term prognosis of those with residual tumor is unclear. The aim of this study was to clarify the necessity of residual tumor resection.

METHODS

We retrospectively reviewed the records of patients diagnosed with intermediate-risk neuroblastoma who either were treated by chemotherapy only (nonresection group; n=16), or received postchemotherapy tumor resection (resection group; n=9).

RESULTS

In the nonresection group, tumor size decreased in 14 patients; 5 had no detectable local tumor at the end of the follow-up period. Tumor size increased in 2 patients 1.5-2.5years postchemotherapy. Both patients received additional treatment and survived. All patients survived during the median follow-up time of 127months. In the resection group, 5 patients received complete resections and 4 patients received nearly complete resections. All patients survived during the median follow-up time of 84months. In 8 out of 9 resected tumors, regression or maturation was pathologically induced by chemotherapy-only treatment.

CONCLUSION

Patients with intermediate-risk neuroblastoma with or without postchemotherapy residual tumor resection had an excellent long-term outcome. The tumor pathology with intermediate-risk neuroblastoma might be susceptible to change to regression or maturation by chemotherapy.

LEVEL OF EVIDENCE

IV.

Neuroblastoma

Neuroblastoma is one of the most common solid tumors in children and has a diverse clinical behavior that largely depends on the tumor biology. Neuroblastoma exhibits unique features, such as early age of onset, high frequency of metastatic disease at diagnosis in patients over 1 year of age and the tendency for spontaneous regression of tumors in infants. The high-risk tumors frequently have amplification of the MYCN oncogene as well as segmental chromosome alterations with poor survival. Recent advanced genomic sequencing technology has revealed that mutation of ALK, which is present in ~10% of primary tumors, often causes familial neuroblastoma with germline mutation. However, the frequency of gene mutations is relatively small and other aberrations, such as epigenetic abnormalities, have also been proposed. The risk-stratified therapy was introduced by the Japan Neuroblastoma Study Group (JNBSG), which is now moving to the Neuroblastoma Committee of Japan Children's Cancer Group (JCCG). Several clinical studies have facilitated the reduction of therapy for children with low-risk neuroblastoma disease and the significant improvement of cure rates for patients with intermediate-risk as well as high-risk disease. Therapy for patients with high-risk disease includes intensive induction chemotherapy and myeloablative chemotherapy, followed by the treatment of minimal residual disease using differentiation therapy and immunotherapy. The JCCG aims for better cures and long-term quality of life for children with cancer by facilitating new approaches targeting novel driver proteins, genetic pathways and the tumor microenvironment.

Management of adrenal masses in patients with Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is a genetic overgrowth and cancer predisposition syndrome, associated with both benign and malignant adrenal findings. Literature review and an institutional case series elucidate the wide spectrum of adrenal findings in BWS patients. The altered expression of the 11p15 region is likely related to adrenal gland hyperplasia and growth dysregulation. Given the absence of guidelines for managing adrenal findings in BWS, we propose a systematic approach to adrenal findings in BWS patients, to allow for maximum detection of potentially malignant pathology without posing additional risk to patients.

Conceptualizing overdiagnosis in cancer screening

The aim of cancer screening is to detect asymptomatic cancers whose treatment will result in extension of life, relative to length of life absent screening. Unfortunately, cancer screening also results in overdiagnosis, the detection of cancers that, in the absence of screening, would not present symptomatically during one's lifetime. Thus, their detection and subsequent treatment is unnecessary and detrimental. This definition of overdiagnosis, while succinct, does not capture the ways it can occur, and our interactions with patients, advocates, researchers, clinicians, and journalists have led us to believe that the concept of overdiagnosis is difficult to explain and, for some, difficult to accept. We propose a dichotomy, the "tumor-patient" classification, to aid in understanding overdiagnosis. The tumor category includes asymptomatic malignant disease that would regress spontaneously if left alone, as well as asymptomatic malignant disease that stagnates or progresses too slowly to be life threatening in even the longest of lifetimes. The patient category includes asymptomatic malignant disease that would progress quickly enough to be life threatening during a lifetime of typical length, but lacks clinical relevance because death due to another cause intercedes prior to what would have been the date of symptomatic diagnosis had screening not occurred. Cancer screening of most organs is likely to result in overdiagnosis of both types. However, the ratio of tumor- to patient-driven overdiagnosis almost certainly varies, and may vary drastically, by organ, screening modality, patient characteristics, and other factors.

Long-term follow-up results of the observation program for neuroblastoma detected at 6-month mass screening

We conducted an observation program of neuroblastoma in infants, detected by mass screening at 6 months of age; we followed up with them for 15 years. No recurrence was observed after disappearance of tumors, and persistent tumors showed no malignant transformation or metastasis. Histology of the resected tumors showed age-related differentiation.

Clinical, biologic, and prognostic differences on the basis of primary tumor site in neuroblastoma: a report from the international neuroblastoma risk group project

PURPOSE

Neuroblastoma (NB) is a heterogeneous tumor arising from sympathetic tissues. The impact of primary tumor site in influencing the heterogeneity of NB remains unclear.

PATIENTS AND METHODS

Children younger than age 21 years diagnosed with NB or ganglioneuroblastoma between 1990 and 2002 and with known primary site were identified from the International Neuroblastoma Risk Group database. Data were compared between sites with respect to clinical and biologic features, as well as event-free survival (EFS) and overall survival (OS).

RESULTS

Among 8,369 children, 47% had adrenal tumors. All evaluated clinical and biologic variables differed statistically between primary sites. The features that were > 10% discrepant between sites were stage 4 disease, MYCN amplification, elevated ferritin, elevated lactate dehydrogenase, and segmental chromosomal aberrations, all of which were more frequent in adrenal versus nonadrenal tumors (P < .001). Adrenal tumors were more likely than nonadrenal tumors (adjusted odds ratio, 2.09; 95% CI, 1.67 to 2.63; P < .001) and thoracic tumors were less likely than nonthoracic tumors (adjusted odds ratio, 0.20; 95% CI, 0.11 to 0.39; P < .001) to have MYCN amplification after controlling for age, stage, and histologic grade. EFS and OS differed significantly according to the primary site (P < .001 for both comparisons). After controlling for age, MYCN status, and stage, patients with adrenal tumors had higher risk for events (hazard ratio, 1.13 compared with nonadrenal tumors; 95% CI, 1.03 to 1.23; P = .008), and patients with thoracic tumors had lower risk for events (HR, 0.79 compared with nonthoracic; 95% CI, 0.67 to 0.92; P = .003).

CONCLUSION

Clinical and biologic features show important differences by NB primary site, with adrenal and thoracic sites associated with inferior and superior survival, respectively. Future studies will need to investigate the biologic origin of these differences.

Trans-population analysis of genetic mechanisms of ethnic disparities in neuroblastoma survival

BACKGROUND

Black patients with neuroblastoma have a higher prevalence of high-risk disease and worse outcome than white patients. We sought to investigate the relationship between genetic variation and the disparities in survival observed in neuroblastoma.

METHODS

The analytic cohort was composed of 2709 patients. Principal components were used to assign patients to genomic ethnic clusters for survival analyses. Locus-specific ancestry was calculated for use in association analysis. The shorter spans of linkage disequilibrium in African populations may facilitate the fine mapping of causal variants in regions previously implicated by genome-wide association studies conducted primarily in patients of European descent. Thus, we evaluated 13 single nucleotide polymorphisms known to be associated with susceptibility to high-risk neuroblastoma from genome-wide association studies and all variants with highly divergent allele frequencies in reference African and European populations near the known susceptibility loci. All statistical tests were two-sided.

RESULTS

African genomic ancestry was associated with high-risk neuroblastoma (P = .007) and lower event-free survival (P = .04, hazard ratio = 1.4, 95% confidence interval = 1.05 to 1.80). rs1033069 within SPAG16 (sperm associated antigen 16) was determined to have higher risk allele frequency in the African reference population and statistically significant association with high-risk disease in patients of European and African ancestry (P = 6.42 × 10(-5), false discovery rate < 0.0015) in the overall cohort. Multivariable analysis using an additive model demonstrated that the SPAG16 single nucleotide polymorphism contributes to the observed ethnic disparities in high-risk disease and survival.

CONCLUSIONS

Our study demonstrates that common genetic variation influences neuroblastoma phenotype and contributes to the ethnic disparities in survival observed and illustrates the value of trans-population mapping.

A prospective study of expectant observation as primary therapy for neuroblastoma in young infants: a Children's Oncology Group study

OBJECTIVE

To demonstrate that expectant observation of young infants with small adrenal masses would result in excellent event-free and overall survival.

BACKGROUND

Neuroblastoma is the most common malignant tumor in infants, and in young infants, 90% of neuroblastomas are located in the adrenal gland. Although surgical resection is standard therapy, multiple observations suggest that expectant observation could be a safe alternative for infants younger than 6 months who have small adrenal masses.

METHODS

A prospective study of infants younger than 6 months with small adrenal masses and no evidence of spreading beyond the primary tumor was performed at participating Children's Oncology Group institutions. Parents could choose observation or immediate surgical resection. Serial abdominal sonograms and urinary vanillylmandelic acid and homovanillic acid measurements were performed during a 90-week interval. Infants experiencing a 50% increase in the volume of the mass, urine catecholamine values, or an increase in the homovanillic acid to vanillylmandelic acid ratio greater than 2, were referred for surgical resection.

RESULTS

Eighty-seven eligible patients were enrolled: 83 elected observation and 4 chose immediate surgery. Sixteen observational patients ultimately had surgery; 8 had International Neuroblastoma Staging System stage 1 neuroblastoma, 2 had higher staged neuroblastoma (2B and 4S), 2 had low-grade adrenocortical neoplasm, 2 had adrenal hemorrhage, and 2 had extralobar pulmonary sequestration. The 2 patients with adrenocortical tumors were resected because of a more than 50% increase in tumor volume. The 3-year event-free survival for a neuroblastoma event was 97.7 ± 2.2% within the entire cohort of patients (n = 87). The 3-year overall survival was 100%, with a median follow-up of 3.2 years. Eighty-one percent of patients on the observation arm were spared resection.

CONCLUSIONS

Expectant observation of infants younger than 6 months with small adrenal masses led to excellent event-free survival and overall survival while avoiding surgical intervention in a large majority of the patients.

The significance of serial histopathology in a residual mass for outcome of intermediate risk stage 3 neuroblastoma

BACKGROUND

To describe the serial histopathology of intermediate risk stage 3 neuroblastoma after chemotherapy, and correlate with residual mass at therapy completion and outcome.

PROCEDURE

A retrospective review of intermediate risk stage 3 neuroblastoma patients treated 1989-2005 at Children's Hospital Los Angeles according to CCG 3881 or CCG 3961 protocols was performed, with central review of histopathology, radiology, and surgery.

RESULTS

Eighteen patients treated per CCG 3881 (n = 9) or CCG 3961 (n = 9), with including 1 (n = 5), 2 (n = 9), ≥ 3 (n = 3), or unknown number (n = 1) of surgical procedures were included. At therapy completion, 10 patients had residual tumor: <10% original size (n = 3), >10% original size (n = 6) (5 MIBG avid; 4 with elevated catecholamines), and CT non-measurable MIBG avid tumor (n = 1). Post-chemotherapy histology showed tumor regression (n = 4); or maturation with (n = 6) or without (n = 2) Schwannian development. Histologic changes correlated with median tumor shrinkage of 80% (regressing tumors) and <25% (maturing tumors). Tumor size increased in one patient with maturing tumor and Schwannian development. Overall survival was 100%.

CONCLUSION

Post-chemotherapy histopathology of intermediate risk stage 3 neuroblastoma was characterized by regression or maturation. Persisting residual and maturing tumors were not associated with tumor progression, despite MIBG uptake and/or elevated catecholamines, supporting observation only. Histopathology should be obtained in future studies to confirm these findings, and guide length of chemotherapy.

Progress in treatment and risk stratification of neuroblastoma: impact on future clinical and basic research

Close international collaboration between pediatric oncologists has led to marked improvements in the cure of patients, seen as a long-term overall survival rate of about 80%. Despite this progress, neuroblastoma remains a challenging disease for both clinicians and researchers. Major clinical problems include lack of acceptable cure rates in high-risk neuroblastoma and potential overtreatment of subsets of patients at low and intermediate risk of the disease. Many years of intensive international cooperation have recently led to a promising joint effort to further improve risk classification for treatment stratification, the new International Neuroblastoma Risk Group Classification System. This approach will facilitate comparison of the results of clinical trials performed by different international collaborative groups. This, in turn, should accelerate refinement of risk stratification and thereby aid selection of appropriate therapies for individual patients. To be able to identify new therapeutic modalities, it will be necessary to elucidate the pathogenesis of the different subtypes of neuroblastoma. Basic and translational research have provided new tools for molecular characterization of blood and tumor samples including high-throughput technologies for analysis of DNA, mRNAs, microRNAs and other non-coding RNAs, as well as proteins and epigenetic markers. Most of these studies are array-based in design. In neuroblastoma research they aim to refine risk group stratification through incorporation of molecular tumor fingerprints and also to enable personalized treatment modalities by describing the underlying pathogenesis and aberrant signaling pathways in individual tumors. To make optimal use of these new technologies for the benefit of the patient, it is crucial to have a systematic and detailed documentation of both clinical and molecular data from diagnosis through treatment to follow-up. Close collaboration between clinicians and basic scientists will provide access to combined clinical and molecular data sets and will create more efficient steps in response to the remaining treatment challenges. This review describes the current efforts and trends in neuroblastoma research from a clinical perspective in order to highlight the urgent clinical problems we must address together with basic researchers.

Racial and ethnic disparities in risk and survival in children with neuroblastoma: a Children's Oncology Group study

PURPOSE

Although health disparities are well-described for many cancers, little is known about racial and ethnic disparities in neuroblastoma. To evaluate differences in disease presentation and survival by race and ethnicity, data from the Children's Oncology Group (COG) were analyzed.

PATIENTS AND METHODS

The racial/ethnic differences in clinical and biologic risk factors, and outcome of patients with neuroblastoma enrolled on COG ANBL00B1 between 2001 and 2009 were investigated.

RESULTS

A total of 3,539 patients (white, 72%; black, 12%; Hispanic, 12%; Asian, 4%; and Native American, < 1%) with neuroblastoma were included. The 5-year event-free survival (EFS) rates were 67% for whites (95% CI, 65% to 69%), 69% for Hispanics (95% CI, 63% to 74%), 62% for Asians (95% CI, 51% to 71%), 56% for blacks (95% CI, 50% to 62%), and 37% for Native American (95% CI, 17% to 58%). Blacks (P < .001) and Native Americans (P = .04) had a higher prevalence of high-risk disease than whites, and significantly worse EFS (P = .01 and P = .002, respectively). Adjustment for risk group abrogated these differences. However, closer examination of the EFS among high-risk patients who remained event free for 2 years or longer, revealed a higher prevalence of late-occurring events among blacks compared with whites (hazard ratio, 1.5; 95% CI, 1.0 to 2.3; P = .04).

CONCLUSION

Black and Native American patients with neuroblastoma have a higher prevalence of high-risk disease, accounting for their worse EFS when compared with whites. The higher prevalence of late-occurring events among blacks with high-risk disease suggests that this population may be more resistant to chemotherapy. Studies focused on delineating the genetic basis for the racial disparities observed in this study are planned.