Immune function in childhood cancer survivors: a Children's Oncology Group review

Seroprevalence of Measles (Rubeola) Antibodies in Childhood Cancer Survivors

Background: Measles is reemerging as a public health threat, raising important questions about disease vulnerability among childhood cancer survivors. This secondary analysis assessed the seroprevalence of anti-measles immunoglobulin G (IgG) antibodies as a marker of immune status in survivors of childhood cancer and associated demographic/treatment variables. Method: Participants were childhood cancer survivors who were free of active disease, having routine blood studies drawn, and could provide documentation of having received two doses of measles, mumps, and rubella vaccine before their cancer diagnosis. Patient record review documented demographic and treatment variables. Antimeasles (rubeola) IgG antibody seroprevalence was assessed by enzyme immunoassay for vaccine-specific antibodies. Results: Of 270 survivors evaluated, 110 (42%) were female, 196 (75%) were White, and 159 (61%) were leukemia/lymphoma survivors. Of these 262, 110 (42%) had negative measles seroprevalence, suggesting loss of immunity. Conclusion: Measles antibody surveillance and the need for reimmunization for survivors of childhood cancer survivors outside the transplant setting remains controversial. Our analysis indicates that a substantial proportion of survivors lose vaccine-related immunity to measles. Pediatric oncology nurses play important roles in educating cancer survivors regarding their risk of measles infection, evaluating the need for reimmunization, correcting misinformation about vaccine safety and effectiveness, and working to optimize community herd-based immunity.

Treatment intensity affects immune reconstitution even after childhood cancer not treated with hematopoietic stem cell transplantation

BACKGROUND

Only a few previous studies examine immune system recovery after completed cancer treatment.

AIMS

The aim of this study was to analyze immune reconstitution after childhood cancer therapy in a non-hematopoietic stem cell transplantation setting.

METHODS AND RESULTS

We analyzed children (N = 79) who received chemotherapy with/without irradiation for cancer diagnosed between 2014 and 2019 at Turku University Hospital, Finland. We retrospectively collected data on baseline parameters and post-treatment immunological recovery, namely neutrophil and lymphocyte counts, IgG levels, CD19, CD4 and natural killer cell counts. Immunological parameters were followed until their normalization. Treatment intensity was stratified according to the Intensity of Treatment Rating Scale (ITR-3). We analyzed the effects of treatment intensity on normalization of immunological parameters across the entire treatment range. Treatment intensity had a major effect on immune system recovery after completion of treatment. Most patients had normal immunological parameters 1-4 months post-treatment both in high- and low-intensity treatment groups, but patients classified in the high-intensity group had low parameters more often than patients in the low-intensity group.

CONCLUSION

Our data suggest a fast recovery of studied immunological parameters after the majority of current pediatric oncologic treatments. Treatment for high-risk acute lymphoblastic leukemia, acute myeloid leukemia, medulloblastoma, and mature B-cell lymphoma was associated with prolonged recovery times for a substantial proportion of cases. High treatment intensity was associated with prolonged immunological recovery.

Association of serum 25-hydroxy-vitamin D concentration and risk of mortality in cancer survivors in the United States

PURPOSE

Cancer survivors have a high risk of mortality, and vitamin D (VD) is associated with the risk of mortality. This study is aim to examine the impact of VD on mortality in cancer survivors.

METHODS

A prospective study was conducted using data from the National Health and Nutrition Examination Survey. Participants were obtained information on their baseline characteristics, dietary habits, comorbidities, lifestyle, and serum 25-hydroxy VD [25(OH)D] concentrations. The weighted Cox proportional hazard and competing risk regression models were used to estimate the hazard ratio and 95% confidence intervals (HR, 95% CI) of mortality for different serum 25(OH)D concentrations. Restricted cubic spline (RCS) curves were utilized to illustrate the dose-response relationship between serum 25(OH)D concentrations and mortality.

RESULTS

The study encompassed 2,495 participants with cancer diagnoses. Multivariate models indicated that, compared to serum 25(OH)D concentrations below 58.5 nmol/L, concentrations exceeding 81.6 nmol/L were associated with reduced HRs for all-cause mortality (HR = 0.70; 95% CI: 0.56-0.87), cardiovascular mortality (HR = 0.53; 95% CI: 0.32-0.86), and cancer-specific mortality (HR = 0.66; 95% CI: 0.45-0.99). RCS curves revealed "L-shaped" associations between serum 25(OH)D concentration and both all-cause and cancer-specific mortality, with threshold effects at 87.9 nmol/L and 84.6 nmol/L, respectively. Conversely, the relationship between serum 25(OH)D concentration and cardiovascular mortality exhibited a more linear pattern, with a threshold at 88.7 nmol/L. Subgroup analyses highlighted a gender-specific interaction that elevated serum 25(OH)D concentrations were significantly more protective against mortality in males than in females, especially regarding cancer-specific mortality (P-interaction = 0.009).

CONCLUSION

Elevated serum 25(OH)D concentrations were correlated with decreased risks of all-cause, cardiovascular, and cancer-specific mortality in cancer survivors, with benefit thresholds at 87.9, 88.7, and 84.6 nmol/L, respectively. These findings suggested that cancer survivors might benefit from higher vitamin D recommendations than the general population.

Current vaccination status and safety of children with peripheral neuroblastoma in the real-world

Background

peripheral neuroblastic tumors (pNT) have high incidence and mortality, and infants are prone to various infectious diseases. The purpose of this study is to understand the immunization status of children with pNT in the real-world and the incidence of adverse reactions after vaccination, and to evaluate the feasibility of vaccination and the influencing factors of vaccination.

Methods

Children with pNT treated in the Children's Hospital Affiliated to Zhejiang University from January 1, 2011 to December 1, 2021 were included. By referring to medical records, the vaccination history of the national immunization program (NIP) vaccines and the occurrence of adverse events following immunization(AEFI), current status and safety of immunization in children with pNT in the real-world were analyzed.

Results

Among 784 children with pNT, 394 were able to obtain the history of vaccination. The overall vaccination rate of NIP vaccines was 71.49% before chemotherapy and 37.67% after chemotherapy, and the recovery time of vaccination after treatment was 16.00 (6.00,24.00) months. Age, time of tumor diagnosis and disease classification were significantly correlated with vaccination. AEFI reported an incidence of 0.23‰.

Conclusion

The vaccination rate of children with pNT is generally low, especially the vaccination rate after chemotherapy. The vaccination safety is good, children should be encouraged to immunize.

Multisystem inflammatory syndrome in 1.2 million children: longitudinal cohort study of risk factors

BACKGROUND

We identified patient characteristics associated with an increased risk of developing MIS-C.

METHODS

We conducted a longitudinal cohort study of 1,195,327 patients aged 0-19 years between 2006 and 2021, including the first two waves of the pandemic (February 25-August 22, 2020 and August 23, 2020-March 31, 2021). Exposures included prepandemic morbidity, birth outcomes, and family history of maternal disorders. Outcomes included MIS-C, Kawasaki disease, and other Covid-19 complications during the pandemic. We calculated risk ratios (RRs) and 95% confidence intervals (CIs) for the association between patient exposures and these outcomes using log-binomial regression models adjusted for potential confounders.

RESULTS

Among 1,195,327 children, 84 developed MIS-C, 107 Kawasaki disease, and 330 other Covid-19 complications during the first year of the pandemic. Prepandemic hospitalizations for metabolic disorders (RR 11.3, 95% CI 5.61-22.6), atopic conditions (RR 3.34, 95% CI 1.60-6.97), and cancer (RR 8.11, 95% CI 1.13-58.3) were strongly associated with the risk of MIS-C, compared with no exposure. These same exposures were also associated with Kawasaki disease and other Covid-19 complications. However, birth characteristics and history of maternal morbidity were not associated with MIS-C development.

CONCLUSIONS

Children with pre-existing morbidity have a considerably elevated risk of MIS-C.

IMPACT

Morbidities that predispose children to multisystem inflammatory syndrome (MIS-C) are unclear. In this study, prepandemic hospitalizations for metabolic disorders, atopic conditions, and cancer were associated with an elevated risk of MIS-C. Birth characteristics and family history of maternal morbidity were not, however, associated with MIS-C. Pediatric morbidities may play a greater role in MIS-C onset than maternal or perinatal characteristics, and may help clinicians better recognize children at risk for this complication.

Effects of Korean red ginseng on T-cell repopulation after autologous hematopoietic stem cell transplantation in childhood cancer patients

Background

Although the survival outcomes of childhood cancer patients have improved, childhood cancer survivors suffer from various degrees of immune dysfunction or delayed immune reconstitution. This study aimed to investigate the effect of Korean Red Ginseng (KRG) on T cell recovery in childhood cancer patients who underwent autologous hematopoietic stem cell transplantation (ASCT) from the perspective of inflammatory and senescent phenotypes.

Methods

This was a single-arm exploratory trial. The KRG group (n = 15) received KRG powder from month 1 to month 12 post-ASCT. We compared the results of the KRG group with those of the control group (n = 23). The proportions of T cell populations, senescent phenotypes, and cytokine production profiles were analyzed at 1, 3, 6, and 12 months post-ASCT using peripheral blood samples.

Results

All patients in the KRG group completed the treatment without any safety issues and showed a comparable T cell repopulation pattern to that in the control group. In particular, KRG administration influenced the repopulation of CD4+ T cells via T cell expansion and differentiation into effector memory cell re-expressing CD45RA (EMRA) cells. Although the KRG group showed an increase in the number of CD4+ EMRA cells, the expression of senescent and exhausted markers in these cells decreased, and the capacity for senescence-related cytokine production in the senescent CD28- subset was ameliorated.

Conclusions

These findings suggest that KRG promotes the repopulation of CD4+ EMRA T cells and regulates phenotypical and functional senescent changes after ASCT in pediatric patients with cancer.

Consensus document of the Spanish Society of Paediatric Infectious Diseases and the Advisory Committee on Vaccines of the Spanish Association of Pediatrics for vaccination of immunosuppressed individuals

The number of people with immunosuppression is increasing considerably due to their greater survival and the use of new immunosuppressive treatments for various chronic diseases. This is a heterogeneous group of patients in whom vaccination as a preventive measure is one of the basic pillars of their wellbeing, given their increased risk of contracting infections. This consensus, developed jointly by the Sociedad Española de Infectología Pediátrica (Spanish Society of Pediatric Infectious Diseases) and the Advisory Committee on Vaccines of the Asociación Española de Pediatría (Spanish Association of Paediatrics), provides guidelines for the development of a personalised vaccination schedule for patients in special situations, including general recommendations and specific recommendations for vaccination of bone marrow and solid organ transplant recipients, children with inborn errors of immunity, oncologic patients, patients with chronic or systemic diseases and immunosuppressed travellers.

Loss of humeral immunity in childhood cancer survivors not having undergone hematopoietic stem cell transplantation

BACKGROUND

Data are limited and conflicting regarding loss of immunity in childhood cancer survivors who did not undergo hematopoietic stem cell transplantation. The purpose of this retrospective, single center study is to provide further data to help build unifying revaccination guidelines post-chemotherapy in childhood cancer survivors not having undergone hematopoietic stem cell transplantation.

METHODS

This retrospective study included 28 childhood cancer survivors, 14 males and 14 females, whose treatment consisted of at least 3 months of chemotherapy and with confirmation of completing their primary vaccination series prior to therapy. The rate of vaccine titer seropositivity for cancer survivors was compared with the expected general population, based on long-term studies of anti-body persistence.

RESULTS

Decreased seropositivity for measles, mumps, rubella, varicella, tetanus, and hepatitis B was found in patients across all categories of malignancy compared with the general population. However, tetanus was not statistically significant. Results were more pronounced for those with hematological malignancies.

CONCLUSIONS

This study indicates that pediatric cancer survivors, especially those with hematological malignancies, may have greater loss of protective antibodies from primary vaccinations. Further studies are needed to provide guidelines for revaccination of both hematologic malignancies and solid tumor childhood cancer survivors who did not undergo hematopoietic stem cell transplantation.

Single-Center Experience in Vaccination of Children in Special Risk Groups: A Multidisciplinary Institutional Consensus Protocol

OBJECTIVE

Despite marked improvements in the accessibility of childhood vaccines, knowledge gaps remain about the vaccination of children in special risk groups (SRG). This study aimed to analyze the clinical data of children vaccinated in SRG in a single-center unit to contribute to the clinical evidence for the specific planning of immunization of children in SRG. The second- ary aim is to present institutional consensus on the vaccination of children in SRG.

MATERIALS AND METHODS

This retrospective study was conducted at a single-center pediatric vaccination clinic. Patient charts between 2018 and 2021 were retrospectively reviewed, and clinical and laboratory data were extracted. Serial joint meetings with multiple healthcare pro- fessionals were performed to develop an institutional protocol for vaccination.

RESULTS

There were 479 children vaccinated between 2018 and 2021 for reasons such as post- chemotherapy, after hematopoietic stem cell transplantation, before/after solid organ trans- plantation, allergies, and chronic diseases. Of these, 298 (62.2%) children vaccinated in the unit due to a history of food or vaccine allergies were excluded. One hundred eighty-one children were vaccinated at a median age of 11 [7-15] years. Most children were vaccinated after treat- ment for malignancies. Solid tumors were the most frequent malignancy (67%), followed by acute lymphoblastic leukemia (29.0%) and acute myeloid leukemia (4.0%). Institutional vacci- nation protocols for cancer survivors, hematopoietic stem cells, and solid organ recipient chil- dren were developed and presented.

CONCLUSION

There is a need to prepare national guidelines for vaccinating children with altered immunocompetence. Sharing vaccination practices by multidisciplinary vaccination units might increase and provide knowledge to develop national policies.

Pediatric cancer care management during the COVID-19 pandemic: a review of the literature and a single-centre real-life experience of an Italian pediatric oncology unit

INTRODUCTION

The severe acute respiratory syndrome coronavirus-2 pandemic significantly affected clinical practice, also in pediatric oncology units. Cancer patients needed to be treated with an adequate dose density despite the SARS-CoV-2 infection, balancing risks of developing severe COVID-19 disease.

AREAS COVERED

Although the pandemic spread worldwide, the prevalence of affected children was low. The percentage of children with severe illness was approximately 1-6%. Pediatric cancer patients represent a prototype of a previously healthy immune system that is hampered by the tumor itself and treatments, such as chemotherapy and steroids. Through a review of the literature, we reported the immunological basis of the response to SARS-CoV-2 infection, the existing antiviral treatments used in pediatric cancer patients, and the importance of vaccination. In conclusion, we reported the real-life experience of our pediatric oncology unit during the pandemic period.

EXPERT OPINION

Starting from the data available in literature, and our experience, showing the rarity of severe COVID-19 disease in pediatric patients with solid tumors, we recommend carefully tailoring all the oncological treatments (chemotherapy/targeted therapy/stem cell transplantation/radiotherapy). The aim is the preservation of the treatment's timing, balanced with an evaluation of possible severe COVID-19 disease.

MMR vaccination timing and long-term immunity among childhood cancer survivors

Long-term seroprotection against the measles and mumps viruses has not been reported in childhood cancer survivor (CCS) who received two-lifetime doses of the measles, mumps, and rubella (MMR) vaccine. We performed a retrospective study of measles and mumps titers among 55 CCS who received standard chemotherapy and two MMR vaccinations at any time. Over 75% of CCS who received at least one MMR prior to their cancer diagnosis had a negative or equivocal titer to measles or mumps. In contrast, all CCS who received the MMR series following their cancer treatment demonstrated long-term seroprotection to both viruses at a mean of 8.2 years after their last vaccination.

A Population-Based Study of the Long-Term Risk of Infections Associated With Hospitalization in Childhood Cancer Survivors

PURPOSE

Infections pose a significant risk during therapy for childhood cancer. However, little is known about the risk of infection in long-term survivors of childhood cancer.

METHODS

We performed a retrospective observational study of children and adolescents born in Washington State diagnosed with cancer before age 20 years and who survived at least 5 years after diagnosis. Survivors were categorized as having a hematologic or nonhematologic malignancy and were matched to individuals without cancer in the state birth records by birth year and sex with a comparator:survivor ratio of 10:1. The primary outcome was incidence of any infection associated with a hospitalization using diagnostic codes from state hospital discharge records. Incidence was reported as a rate (IR) per 1,000 person-years. Multivariate Poisson regression was used to calculate incidence rate ratios (IRR) for cancer survivors versus comparators.

RESULTS

On the basis of 382 infection events among 3,152 survivors and 771 events among 31,519 comparators, the IR of all hospitalized infections starting 5 years after cancer diagnosis was 12.6 (95% CI, 11.4 to 13.9) and 2.4 (95% CI, 2.3 to 2.6), respectively, with an IRR 5.1 (95% CI, 4.5 to 5.8). The survivor IR during the 5- to 10-year (18.1, 95% CI, 15.9 to 20.5) and > 10-year postcancer diagnosis (8.3, 95% CI, 7.0 to 9.7) periods remained greater than comparison group IRs for the same time periods (2.3, 95% CI, 2.1 to 2.6 and 2.5, 95% CI, 2.3 to 2.8, respectively). When potentially vaccine-preventable infections were evaluated, survivors had a greater risk of infection relative to comparators (IRR, 13.1; 95% CI, 7.2 to 23.9).

CONCLUSION

Infectious complications continue to affect survivors of childhood cancer many years after initial diagnosis. Future studies are needed to better understand immune reconstitution to determine specific factors that may mitigate this risk.

Human papillomavirus vaccination uptake among childhood cancer survivors in Western New York

INTRODUCTION

The risk of human papillomavirus (HPV)-associated cancers is significantly higher among survivors of a childhood cancer compared to the general population. Despite this, their HPV vaccine uptake rates are lower. We examined factors related to HPV vaccine uptake among childhood cancer survivors from Western New York over 13 years following the introduction of HPV vaccines.

METHODS

Retrospective review of patients diagnosed with invasive or noninvasive cancerous conditions at age 9 or younger treated at Roswell Park Oishei Children's Cancer and Blood Disorder Program. We matched vaccine date information for patients aged 9-26 years between 2006 and 2020 from the New York State Immunization Information System. Demographic and cancer-related information was abstracted from electronic medical records. Cumulative vaccine uptake was assessed by Kaplan-Meier and Cox proportional hazards regression models.

RESULTS

A total of 284 patients were included in the analyses. Most were non-Hispanic/White (80.3%) and resided in a metropolitan area (81.7%). Approximately half had leukemia or lymphoma (54.9%), and most received chemotherapy. Females were more likely to initiate the HPV vaccine and did so sooner (median = 5.5 years) than males (median = 5.7 years; log-rank p = .301). Patients who were older at vaccine eligibility and males who received blood product transfusions were significantly less likely to initiate the HPV vaccine.

CONCLUSION

While rates of HPV vaccine initiation have been increasing with time among childhood cancer survivors, they remain low overall, with differences seen by treatment and diagnosis. Our findings support the need for further research to optimize HPV vaccine delivery in cancer care.

Multimorbidity patterns and risk of hospitalisation in children: A population cohort study of 3.6 million children in England, with illustrative examples from childhood cancer survivors

Background

Population-level estimates of hospitalisation risk in children are currently limited. The study aims to characterise morbidity patterns in all children, focusing on childhood cancer survivors versus children without cancer.

Methods

Employing hospital records of children aged <19 years between 1997 to 2018 in England, we characterised morbidity patterns in childhood cancer survivors compared with children without cancer. The follow-up began on the 5^th anniversary of the index hospitalisation and the primary outcome was the incidence of comorbidities.

Findings

We identified 3,559,439 eligible participants having 12,740,666 hospital admissions, with a mean age at study entry of 11.2 years. We identified 32,221 patients who survived for at least 5 years since their initial cancer diagnosis. During the follow-up period and within the whole population of 3.6 million children, the leading conditions for admission were (i) metabolic, endocrine, digestive renal and genitourinary conditions (84,749, 2.5%), (ii) neurological (35,833, 1.0%) and (iii) musculoskeletal or skin conditions (23,574, 0.7%), fever, acute respiratory and sepsis (22,604, 0.7%). Stratified analyses revealed that females and children from socioeconomically deprived areas had a higher cumulative incidence for morbidities requiring hospitalisation (p < 0.001). At baseline (5 years after the initial cancer diagnosis or initial hospitalisation for survivors and population comparisons, respectively), cancer survivors experienced a higher prevalence of individual conditions and multimorbidity (≥ 2 morbidities) compared with children without cancer. Cox regression analyses showed that survivors had at least a 4-fold increase in the risk of hospitalisation for conditions such as chronic eye conditions (hazard ration (HR):4.0, 95% confidence interval (CI): 3.5-4.7), fever requiring hospitalisation (HR: 4.4, 95% CI: 3.8-5.0), subsequent neoplasms (HR: 5.7, 95% CI:5.0-6.5), immunological disorders (HR: 6.5, 95% CI:4.5-9.3) and metabolic conditions (HR: 7.1, 95% CI:5.9-8.5).

Interpretation

The overall morbidity burden among children was low in general; however, childhood cancer survivors experienced a higher prevalence and subsequent risk of hospitalisation for a range of morbidities. Targeted policies may be required to promote awareness on health vulnerabilities and gender disparity and to improve advocacy for healthcare in deprived communities.

Funding

Wellcome Trust, National Institute for Health Research (NIHR) University College London Hospitals Biomedical Research Centre, NIHR Great Ormond Street Hospital Biomedical Research Centre and Academy of Medical Sciences. The funders of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report.

Patient-reported outcomes are under-utilised in evaluating supportive therapies in paediatric oncology - A systematic review of clinical trial registries

BACKGROUND

Children with cancer suffer from numerous symptoms and side-effects, making supportive interventions indispensable to improve their quality of life. The gold standard for evaluating the latter is patient-reported outcome (PRO) assessment. This systematic review investigates the current practice of clinical outcome assessment (COA) in clinical trials on supportive interventions.

METHODS

ClinicalTrials.gov and EudraCT were searched for trials including children and adolescents (≤21 years) with cancer receiving supportive care registered 2007-2020. The use of different types of COAs was analysed, focusing on PRO assessment and the domains measured with PRO measures (PROMs). Associations with trial characteristics were investigated using univariate and multivariable analyses.

RESULTS

Of 4789 identified trials, 229 were included. Among them, 44.1 % relied on PROMs, the most commonly used COA. The proportion of trials using PROMs did not significantly differ over time. In the multivariable analysis, intervention type (higher PROM use in behavioural vs. medical interventional trials) and cancer type (higher PROM use in mixed and solid tumour samples vs. haematological samples) were significant predictors of PROM use. The majority of trials using PROMs (59.6 %) measured more than one health domain. 'Physical health' was the most frequently assessed domain (92.6 %).

CONCLUSION

Less than half of registered clinical trials investigating supportive interventions for children with cancer used PROMs. This result is striking since supportive care explicitly focuses on patients' quality of life, which is best assessed using PROMs. Our systematic review underlines the need to identify barriers for PROM implementation and to improve PRO research in paediatric oncology.

Antibody waning after immunosuppressive chemotherapy and immunomodulators, re-immunization considerations in pediatric patients with malignancy and chronic immune thrombocytopenic purpura

Introduction

Immunosuppressive chemotherapy increase the risk of vaccine-preventable infectious diseases in children; nevertheless, chemotherapy may result in delay or miss updated immunization schedules. The predictable antibody waning after incomplete primary immunization series may be intensified at the end of chemotherapy. This study aimed to investigate post-chemotherapy vaccine immunity waning at the end of immunosuppressive therapy in children with malignancy and hematologic disorders.

Materials and methods

Children with malignancies and hematologic disorders including chronic immune thrombocytopenic purpura (ITP) younger than 18 years old were enrolled from September 2015 to August 2019. Eligible patients who completed their treatment protocol for at least 6 months were recruited. The patient information, including sex, age at the date of diagnosis, number of chemotherapy sessions, underlying disease, and vaccination history, was taken by chart review using predefined questionnaires. The patient’s blood samples were obtained, and serum IgG antibody titer checked against diphtheria, tetanus, hepatitis B virus (HBV), mumps, measles, and rubella (MMR) were measured by enzyme-linked immunosorbent assay (ELISA).

Results

110 children receiving immunosuppressive chemotherapy were recruited. Forty-four (40%) of the children tested were girls and 66 (60%) were boys. The mean age of patients was 5.5 years with a range of 2 to 13 years. Of 110 studied children, 27.3% were seronegative for all antibodies. On average, patients undergo 19 episodes of chemotherapy. The mean chemotherapy sessions were significantly greater in children who were seronegative for all tested antibodies (mean: 36.2, 95% CI 33.16 to 39.24, p-value < 0.001). No statistically significant differences were observed regarding the patient’s sex and age between the seropositive and seronegative groups (p-value 0.513 and 0.060, respectively). Based on Poisson regression model analysis, the female gender was associated with 37% lower odds of seronegativity (incidence rate ratio (IIR): 0.63; [95% conf. interval: 0.39 to 1.01, p-value: 0.55]), while chemotherapy sessions 30 or more was associated with significant odds of seronegativity for all tested vaccines (IIR: 25.41; [95% conf. interval: 6.42 to 100.57, p-value < 0.001]).

Conclusion

Our results reemphasized planned catchup immunization in children undergoing immunosuppressive chemotherapy for malignancy, especially against tetanus, diphtheria, and hepatitis B at least 6 months after the end of chemotherapy sessions.

[Application of "kindergarten effect" in radiotherapy for children with tumor aged 3-5 years]

OBJECTIVES

To study the clinical application effect of "kindergarten effect" in radiotherapy for children with tumor based on the psychology of preschool children aged 3-5 years.

METHODS

A total of 30 children, aged 3-5 years, who were admitted to the Department of Radiotherapy, Tianjin Medical University Cancer Institute and Hospital, from January 2020 to August 2021 were enrolled in this prospective study. The children were randomly divided into a control group and a test group, with 15 children in each group. The children in the test group were treated in "kindergarten mode", i.e., all children were treated together at a specified time and left together after all children completed treatment. Those in the control group were treated alternately with adult patients according to the treatment time based on the type of radiotherapy fixation device. The treatment compliance was evaluated for both groups, and the two groups were compared in terms of the setup errors in the superior-inferior (SI), left-right (LR), and anterior-posterior (AP) directions.

RESULTS

Compared with the control group, the test group showed a significantly shorter time for finishing the treatment (P<0.05) and a significantly lower proportion of children with treatment interruption (P<0.05). Compared with the control group, the test group showed smaller mean errors in the SI, LR and AP directions after image-guided radiotherapy, with significant differences in the mean errors in the SI and LR directions (P<0.05).

CONCLUSIONS

With the application of the "kindergarten effect", most children can actively cooperate in radiotherapy, and it can also improve the accuracy and repeatability of positioning and help to achieve the desired treatment outcome.

Short NK and naïve T-cell telomere length is associated with thyroid cancer in childhood cancer survivors: A report from the Childhood Cancer Survivor Study

BACKGROUND

Survivors of childhood cancer are at risk for therapy-related subsequent malignant neoplasms (SMN), including thyroid SMN. Telomere length (TL) is associated with cancer risk, but the relationship between TL and SMN risk among survivors is less clear.

METHODS

We conducted a nested, matched case-control study of radiation-exposed 15-year+ adult survivors of childhood cancer with thyroid SMN (cases) and without SMN (controls). 46 cases were matched to 46 controls by primary diagnosis, chemotherapy (yes/no), radiation field, and follow-up duration. Lymphocyte TL (LTL) was measured by telomere flow-FISH cytometry using blood samples banked at a mean of 38.9 years (cases), 39.2 years (controls). Genetic variation in telomere genes was assessed by whole genome sequencing. Point estimates for LTL <10th percentile were determined for cases and controls.

RESULTS

Cases had shorter median LTL than controls in three out of four leukocyte subsets. Cases were more likely to have NK cell LTL <10th percentile (p=0.01), and 2.8-fold more likely to have naïve T-cell LTL <10th percentile than controls (CI 1.07, 8.78). Five out of 15 cases with a rare indel or missense variant had naïve T-cell LTL <10th percentile, compared with one out of 8 controls.

CONCLUSIONS

Long-term survivors have shorter than expected LTL, a finding that is more pronounced among survivors with thyroid SMN.

IMPACT

The long-term impact of childhood cancer treatment on immune function is poorly understood. Our findings support immune function studies in larger survivor cohorts to assess long-term deficits in adaptive and innate immunity that may underlie SMN risk.

Immunogenicity and safety of the human papillomavirus vaccine in young survivors of cancer in the USA: a single-arm, open-label, phase 2, non-inferiority trial

BACKGROUND

Young survivors of cancer are at increased risk for cancers that are related to human papillomavirus (HPV), primarily caused by oncogenic HPV types 16 and 18. We aimed to examine the immunogenicity and safety of the three-dose series of HPV vaccine in young survivors of cancer.

METHODS

We conducted an investigator-initiated, phase 2, single-arm, open-label, non-inferiority trial at five National Cancer Institute-designated comprehensive cancer centres in the USA. Eligible participants were survivors of cancer who were HPV vaccine-naive, were aged 9-26 years, in remission, and had completed cancer therapy between 1 and 5 years previously. Participants received three intramuscular doses of either quadrivalent HPV vaccine (HPV4; enrolments on or before March 1, 2016) or nonavalent HPV vaccine (HPV9; enrolments after March 1, 2016) over 6 months (on day 1, at month 2, and at month 6). We also obtained data from published clinical trials assessing safety and immunogenicity of HPV4 and HPV9 in 9-26-year-olds from the general population, as a comparator group. The primary endpoint was antibody response against HPV types 16 and 18 at month 7 in the per-protocol population. A response was deemed non-inferior if the lower bound of the multiplicity-adjusted 95% CI was greater than 0·5 for the ratio of anti-HPV-16 and anti-HPV-18 geometric mean titres (GMTs) in survivors of cancer versus the general population. Responses were examined separately in male and female participants by age group (ie, 9-15 years and 16-26 years). Safety was assessed in all participants who received at least one vaccine dose and for whom safety data were available. This study is registered with ClinicalTrials.gov, NCT01492582. This trial is now completed.

FINDINGS

Between Feb 18, 2013, and June 22, 2018, we enrolled 453 survivors of cancer, of whom 436 received one or more vaccine doses: 203 (47%) participants had survived leukaemia, 185 (42%) were female, and 280 (64%) were non-Hispanic white. Mean age at first dose was 15·6 years (SD 4·6). 378 (83%) of 453 participants had evaluable immunogenicity data; main reasons for exclusion from per-protocol analysis were to loss to follow-up, patient reasons, and medical reasons. Data were also obtained from 26 486 general population controls. The ratio of mean GMT for anti-HPV types 16 and 18 in survivors of cancer versus the general population was more than 1 for all subgroups (ie, aged 9-15 years, aged 16-26 years, male, and female groups) in both vaccine cohorts (ranging from 1·64 [95% CI 1·12-2·18] for anti-HPV type 16 in female participants aged 9-15 years who received HPV9, to 4·77 [2·48-7·18] for anti-HPV type 18 in male participants aged 16-26 years who received HPV4). Non-inferiority criteria were met within each age and sex subgroup, except against HPV type 18 in female participants aged 16-26 years receiving HPV9 (4·30 [0·00-9·05]). Adverse events were reported by 237 (54%) of 435 participants; injection site pain was most common (174 [40%] participants). One serious adverse event (ie, erythema nodosum) was possibly related to vaccine (HPV9; 16-26 year female cohort).

INTERPRETATION

Immunogenicity and safety of HPV vaccine three-dose series in survivors of cancer is similar to that in the general population, providing evidence for use in this clinically vulnerable population.

FUNDING

US National Cancer Institute, Merck, Sharp & Dohme, and American Lebanese Syrian Associated Charities.