Childhood and adult cancers: contrasts and commonalities

The feasibility of implementing Toronto childhood cancer stage guidelines and estimating the impact on outcome for childhood cancers in seven pediatric oncology units in sub-Saharan Africa. A study from the Franco-African Pediatric Oncology Group

BACKGROUND

The improvement of childhood cancer outcome is determined by early diagnosis, effective treatment, supportive care, and adequate medical follow-up. Stage at diagnosis may reflect timeliness of diagnosis, therefore standardized registration of stage is essential for interpretation of regional differences and time trends in survival. Here, we describe the feasibility of implementing the Toronto Childhood Cancer Stage Guidelines (hereafter Toronto Guidelines [TG]) in the hospital-based cancer registry of the Franco-African Pediatric Oncology Group (GFAOP), and assess the impact of TG stage on outcome in pediatric oncology units (POUs) in seven low- and middle-income countries in sub-Saharan Africa (SSA).

METHODS

All cancer patients diagnosed before 15 years of age with one of the 15 cancer types defined in TG, resident in one of the participating countries, and attending one of the selected POUs in 2017-2019 were included. Stage was assigned according to TG. Patients were followed-up for vital status for at least 12 months post diagnosis. Survival at 3, 6, and 12 months was calculated using Kaplan-Meier method and compared between POUs and tumor groups using log-rank test.

RESULTS

TG stage was assigned to 1772 of 2446 (89%) cases diagnosed with one of 11 cancer types. It was not possible to assign TG stage to acute lymphoblastic leukemia (ALL) and the three types of the central nervous system tumors included in the TG. One-year overall survival (OS) was 58% [95% confidence interval: 55-60] and varied between POUs. Survival declined with increasing stage for four tumor types and was statistically significant for two.

CONCLUSION

Except for ALL and brain tumors, we demonstrated feasibility of TG implementation for childhood solid cancers in participating POUs in SSA, and provided a baseline assessment of childhood cancer outcomes against which future stage distribution and survival can be measured as timelines of diagnosis improve over time within the GFAOP network.

Bimodal Age Distribution in Cancer Incidence

Cancer is caused by accumulation of genetic changes which include activation of protooncogenes and loss of tumor suppressor genes. The age-specific incidence of cancer in general increases with advancing age. However, some cancers exhibit a bimodal distribution. Commonly recognized cancers with bimodal age distribution include acute lymphoblastic leukemia, osteosarcoma, Hodgkin's lymphoma, germ cell tumors and breast cancer. Delayed infection hypothesis has been used to provide explanation for the early childhood peak in leukemias and lymphomas, whereas the peak at an older age is associated with accumulation of protooncogenes and weakened immune system. Further genetic analysis and histopathological variations point to distinctly different cancers, varying genetically and histologically, which are often combined under a single category of cancers. Tumor characteristics and age distribution of these cancers varies also by population groups and has further implications on cancer screening methods. Although significant advances have been made to explain the bimodal nature of such cancers, the specific genetic mechanisms for each age distribution remain to be elucidated. Further distinction among the different cancer subtypes may lead to improvements in individual risk assessments, prevention and enhancement of treatment strategies.

Pediatric versus adult high grade glioma: Immunotherapeutic and genomic considerations

High grade gliomas are identified as malignant central nervous tumors that spread rapidly and have a universally poor prognosis. Historically high grade gliomas in the pediatric population have been treated similarly to adult high grade gliomas. For the first time, the most recent classification of central nervous system tumors by World Health Organization has divided adult from pediatric type diffuse high grade gliomas, underscoring the biologic differences between these tumors in different age groups. The objective of our review is to compare high grade gliomas in the adult versus pediatric patient populations, highlighting similarities and differences in epidemiology, etiology, pathogenesis and therapeutic approaches. High grade gliomas in adults versus children have varying clinical presentations, molecular biology background, and response to chemotherapy, as well as unique molecular targets. However, increasing evidence show that they both respond to recently developed immunotherapies. This review summarizes the distinctions and commonalities between the two in disease pathogenesis and response to therapeutic interventions with a focus on immunotherapy.

Systemic delivery of TNF-armed myxoma virus plus immune checkpoint inhibitor eliminates lung metastatic mouse osteosarcoma

Solid cancers that metastasize to the lungs represent a major therapeutic challenge. Current treatment paradigms for lung metastases consist of radiation therapy, chemotherapies, and surgical resection, but there is no single treatment or combination that is effective for all tumor types. To address this, oncolytic myxoma virus (MYXV) engineered to express human tumor necrosis factor (vMyx-hTNF) was tested after systemic administration in an immunocompetent mouse K7M2-Luc lung metastatic osteosarcoma model. Virus therapy efficacy against pre-seeded lung metastases was assessed after systemic infusion of either naked virus or ex vivo-loaded autologous bone marrow leukocytes or peripheral blood mononuclear cells (PBMCs). Results of this study showed that the PBMC pre-loaded strategy was the most effective at reducing tumor burden and increasing median survival time, but sequential intravenous multi-dosing with naked virus was comparably effective to a single infusion of PBMC-loaded virus. PBMC-loaded vMyx-hTNF also potentially synergized very effectively with immune checkpoint inhibitors anti-PD-1, anti-PD-L1, and anti-cytotoxic T lymphocyte associated protein 4 (CTLA-4). Finally, in addition to the pro-immune stimulation caused by unarmed MYXV, the TNF transgene of vMyx-hTNF further induced the unique expression of numerous additional cytokines associated with the innate and adaptive immune responses in this model. We conclude that systemic ex vivo virotherapy with TNF-α-armed MYXV represents a new potential strategy against lung metastatic cancers like osteosarcoma and can potentially act synergistically with established checkpoint immunotherapies.

Examining the Potential Relationship Between Multidisciplinary Team Meetings and Patient Survival in Pediatric Oncology Settings: A Systematic Review

The organization of multidisciplinary team meetings (MTMs) has become standard practice in pediatric oncology and is widely felt to improve communication, knowledge, and patient care. Although the impact of MTMs on survival in adult oncology has been extensively researched, the potential benefits of survival for pediatric cancer patients are still unclear. This systematic review aimed to examine the impact of MTMs on survival in pediatric oncology settings. Relevant studies were identified by searching MEDLINE/PubMed, EMBASE, and the Cochrane Library databases up to January 2020, resulting in 325 unique records. After the title/abstract and full-text screening, 5 studies were included. All of the included studies (one prospective and 4 retrospective cohort studies) described a difference in overall or event-free survival when comparing patients who were discussed in MTMs with non-MTM patients. This association was statistically significant in 3 studies. The quality of the studies was strongly affected by their design. Because of the small number of studies in combination with high clinical and methodological heterogeneity, this review was unable to definitively assert a causal relationship between MTMs and survival in pediatric cancer patients. Further research is needed to explore this relationship and allow cost-benefit analyses, so that time and resources are optimally spent to deliver the best possible care to childhood cancer patients.

A review of the types of childhood cancer associated with a medical X-ray examination of the pregnant mother

PURPOSE

For 65 years the interpretation of the statistical association between the risk of cancer in a child and a prior diagnostic X-ray examination of the abdomen of the pregnant mother has been debated. The objections to a direct cause-and-effect explanation of the association vary in their strength, but one of the most notable grounds for controversy is the finding from the first and largest case-control study reporting the association, the Oxford Survey of Childhood Cancers (OSCC), of an almost uniformly raised relative risk (RR) for nearly all of the types of cancer that are most frequent in children. Here we compare the antenatal X-ray associations found in the OSCC for different types of childhood cancer with the results of all other case-control and case-cohort studies appropriately combined in meta-analyses, and we also review the findings of the few cohort studies that have been conducted.

CONCLUSIONS

From the case-control/case-cohort studies other than the OSCC there are consistent and clear elevations of risk for all types of childhood cancer combined, all leukemia, and all cancers except leukemia combined. This compatibility of the findings of the OSCC with those of the combined other studies is less clear, or effectively absent, when some categories containing smaller numbers of incident cases/deaths are considered, but lack of precision of risk estimates due to sparse data presents inferential challenges, although there is a consistent absence of an association for bone tumors. Further, more recent studies almost certainly address lower intrauterine doses, with an anticipated decrease in estimated risks, which could be misleading when comparisons involve a limited number of studies that are mainly from later years, and a similar problem arises when having to employ all types of antenatal X-ray exposures for a study because data for abdominal exposures are absent. The problem of low statistical power is greater for cohort studies, and this, together with other shortcomings identified in the studies, limits the interpretational value of results. The findings of non-medical intrauterine exposure studies are constrained by sparse data and make a limited contribution to an understanding of the association. Certain aspects of the various studies require a need for caution in interpretation, but overall, the appropriate combination of all case-control/case-cohort studies other than the OSCC lends support to the inference that low-level exposure to radiation in utero proportionally increases the risk of the typical cancers of childhood to around the same level.

Childhood cancers in a section of the South African private health sector: Analysis of medicines claims data

Background

Although childhood cancers are rare, increases in incidence have been observed in recent times. There is a paucity of data on the current incidence of childhood cancers in South Africa.

Aim

This study described the epidemiology of childhood cancers in a section of the private health sector of South Africa, using medicines claims data.

Setting

This study was designed on a nationally representative medicine claims database.

Method

A longitudinal open-cohort study employing children younger than 19 years and diagnosed with cancers between 2008 and 2017 was conducted using medicine claims data from a South African Pharmaceutical Benefit Management company. Cases were identified using International Classification of Diseases, Tenth Revision (ICD-10) diagnostic codes C00 to C97, together with a medicine claim reimbursed from oncology benefits. Crude incidence rates were calculated per million persons younger than 19 years on the database and standardised using the Segi 1960 world population. Temporal trends in incidence rates, analysed using the joinpoint regression, were reported as annual percentage changes (APCs).

Results

Overall, 173 new cases of childhood cancers were identified in the database, translating into an age-standardised incidence rate (ASR) of 82.3 per million. Annual incidence of cancer decreased from 76.7 per million in 2008 to 58.2 per million in 2017. More incident cases were identified in males (68.8%). The highest proportion of incident cases was recorded for leukaemias (39.9%), the 5–9 year age group (34.1%) and the Gauteng Province (49.7%).

Conclusion

The incidence of childhood cancers decreased over time in the section of the private health sector studied. Leukaemias were the major drivers of childhood cancer incidence.

Association of In Vitro Fertilization With Childhood Cancer in the United States

IMPORTANCE

In vitro fertilization (IVF) is associated with birth defects and imprinting disorders. Because these conditions are associated with an increased risk of childhood cancer, many of which originate in utero, descriptions of cancers among children conceived via IVF are imperative.

OBJECTIVE

To compare the incidence of childhood cancers among children conceived in vitro with those conceived naturally.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective, population-based cohort study linking cycles reported to the Society for Assisted Reproductive Technology Clinical Outcomes Reporting System from January 1, 2004, to December 31, 2012, that resulted in live births from September 1, 2004, to December 31, 2013, to the birth and cancer registries of 14 states, comprising 66% of United States births and 75% of IVF-conceived births, with follow-up from September 1, 2004, to December 31, 2014. The study included 275 686 children conceived via IVF and a cohort of 2 266 847 children, in which 10 births were randomly selected for each IVF birth. Statistical analysis was performed from April 1, 2017, to October 1, 2018.

EXPOSURE

In vitro fertilization.

MAIN OUTCOMES AND MEASURES

Cancer diagnosed in the first decade of life.

RESULTS

A total of 321 cancers were detected among the children conceived via IVF (49.1% girls and 50.9% boys; mean [SD] age, 4.6 [2.5] years for singleton births and 5.9 [2.4] years for multiple births), and a total of 2042 cancers were detected among the children not conceived via IVF (49.2% girls and 50.8% boys; mean [SD] age, 6.1 [2.6] years for singleton births and 4.7 [2.6] years for multiple births). The overall cancer rate (per 1 000 000 person-years) was 251.9 for the IVF group and 192.7 for the non-IVF group (hazard ratio, 1.17; 95% CI, 1.00-1.36). The rate of hepatic tumors was higher among the IVF group than the non-IVF group (hepatic tumor rate: 18.1 vs 5.7; hazard ratio, 2.46; 95% CI, 1.29-4.70); the rates of other cancers did not differ between the 2 groups. There were no associations with specific IVF treatment modalities or indication for IVF.

CONCLUSIONS AND RELEVANCE

This study found a small association of IVF with overall cancers of early childhood, but it did observe an increased rate of embryonal cancers, particularly hepatic tumors, that could not be attributed to IVF rather than to underlying infertility. Continued follow-up for cancer occurrence among children conceived via IVF is warranted.

Global Pediatric Oncology: Lessons From Partnerships Between High-Income Countries and Low- to Mid-Income Countries

Partnerships between medical institutions in high-income countries (HICs) and low- to mid-income countries (LMICs) have succeeded in initiating and expanding pediatric cancer control efforts. The long-term goal is consistently a sustainable national pediatric cancer program. Here, we review the elements required for successful implementation, development, and long-term sustainability of pediatric cancer programs in LMICs that first arise as partnerships with institutions in HICs. Although plans must be adapted to each country's resources, certain components are unfailingly necessary. First, an essential step is provision of treatment regardless of ability to pay. Second, financial support for program development and long-term sustainability must be sought from sources both international and local, public and private. A local leader, typically a well-trained pediatric oncologist who devotes full-time effort to the project, should direct medical care and collaborate with hospital, governmental, and community leadership and international agencies. Third, nurses must be trained in pediatric cancer care and allowed to practice this specialty full-time. It is also essential to develop a grassroots organization, such as a foundation, dedicated solely to pediatric oncology. Its members must be trained and educated to provide pediatric cancer advocacy, fundraising, and (in concert with government) program sustainability. Finally, a project mentor in the HIC is crucial and should explore the possibility of collaborative research in the LMIC, which may offer significant opportunities. Relationships between the partnership's leaders and influential individuals in the community, hospital, grassroots foundation, and government will lay the foundation for productive collaboration and a sustainable pediatric oncology program.

Emerging issues among adolescent and young adult cancer survivors

OBJECTIVES

To review the characteristics of cancer in the adolescence and young adult age group; the medical, psychosocial and behavioral late effects; survivorship care planning and transition; current research priorities; and practice implications.

DATA SOURCE

Published articles, research studies and position statements.

CONCLUSION

Survivors of cancers that occurred during adolescence and young adulthood (AYA) are confronted with the dual demands of managing their transition to independent adulthood, concurrently with their transition from cancer patient to cancer survivors, with an associated reduction in support from medical services. AYA survivors also face complex medical, psychosocial and behavioral late effects, including fertility and mental health issues.

IMPLICATIONS FOR NURSING PRACTICE

An understanding of the impact of cancer diagnoses among this age group, including survivors' abilities to reintegrate into 'normal' life and potential long term consequences, is necessary to provide the best support. This care and support can be enhanced through multidisciplinary teams who work together to address the medical and psychosocial needs of AYAs diagnosed with cancer.