Avascular necrosis of bone after allogeneic hematopoietic cell transplantation in children and adolescents

Total Joint Arthroplasty Is a Viable Treatment Option for Patients With Osteonecrosis and Osteoarthritis After Bone Marrow Transplantation

Background

Long-term survival in patients who receive bone marrow transplantation (BMT) is increasing. However, osteonecrosis and secondary osteoarthritis (OA) of the hip and knee are common complications in this population due to post-transplant steroid treatment to prevent graft vs host disease. The purpose of this study was to evaluate the outcomes of total joint arthroplasty (TJA) in patients with prior BMT and compare them to those of patients undergoing TJA for primary OA.

Methods

Patients with a history of BMT undergoing primary TJA from 2013 to 2021 were retrospectively reviewed. Patients were matched 1:1 by surgical site, sex, age, body mass index, American Society of Anesthesiologists score, and Elixhauser Comorbidity Index to patients undergoing TJA for primary OA. Demographics, intraoperative blood loss, perioperative transfusion requirements, hospital length of stay, 90-day emergency department visits and readmissions, all-cause revisions, and 2-year mortality were compared between cohorts.

Results

There were 17 patients undergoing total knee arthroplasty (TKA) after BMT (TKA-BMT) and 43 patients undergoing total hip arthroplasty (THA) after BMT (THA-BMT). More TKA-BMT and THA-BMT patients were immunosuppressed preoperatively compared to 17 matched TKA-OA and 43 THA-OA patients (P = .018 and P < .001). There were no other significant perioperative differences between BMT and OA groups. Two-year patient and implant survivorship for TKA-BMT and THA-BMT patients were high and not statistically different from TKA-OA and THA-OA cohorts.

Conclusions

TJA after BMT provides satisfactory perioperative and short-term outcomes and is a viable treatment option for patients with osteonecrosis and secondary OA after BMT treatment.

International recommendations for screening and preventative practices for long-term survivors of transplantation and cellular therapy: a 2023 update

As hematopoietic cell transplantation (HCT) and cellular therapy expand to new indications and international access improves, the volume of HCT performed annually continues to rise. Parallel improvements in HCT techniques and supportive care entails more patients surviving long-term, creating further emphasis on survivorship needs. Survivors are at risk for developing late complications secondary to pre-, peri- and post-transplant exposures and other underlying risk-factors. Guidelines for screening and preventive practices for HCT survivors were originally published in 2006 and updated in 2012. To review contemporary literature and update the recommendations while considering the changing practice of HCT and cellular therapy, an international group of experts was again convened. This review provides updated pediatric and adult survivorship guidelines for HCT and cellular therapy. The contributory role of chronic graft-versus-host disease (cGVHD) to the development of late effects is discussed but cGVHD management is not covered in detail. These guidelines emphasize special needs of patients with distinct underlying HCT indications or comorbidities (e.g., hemoglobinopathies, older adults) but do not replace more detailed group, disease, or condition specific guidelines. Although these recommendations should be applicable to the vast majority of HCT recipients, resource constraints may limit their implementation in some settings.

International Recommendations for Screening and Preventative Practices for Long-Term Survivors of Transplantation and Cellular Therapy: A 2023 Update

As hematopoietic cell transplantation (HCT) and cellular therapy expand to new indications and international access improves, the number of HCTs performed annually continues to rise. Parallel improvements in HCT techniques and supportive care entails more patients surviving long term, creating further emphasis on survivorship needs. Survivors are at risk for developing late complications secondary to pretransplantation, peritransplantation, and post-transplantation exposures and other underlying risk factors. Guidelines for screening and preventive practices for HCT survivors were originally published in 2006 and then updated in 2012. An international group of experts was convened to review the contemporary literature and update the recommendations while considering the changing practices of HCT and cellular therapy. This review provides updated pediatric and adult survivorship guidelines for HCT and cellular therapy. The contributory role of chronic graft-versus-host disease (cGVHD) to the development of late effects is discussed, but cGVHD management is not covered in detail. These guidelines emphasize the special needs of patients with distinct underlying HCT indications or comorbidities (eg, hemoglobinopathies, older adults) but do not replace more detailed group-, disease-, or condition-specific guidelines. Although these recommendations should be applicable to the vast majority of HCT recipients, resource constraints may limit their implementation in some settings.

Non-osteopenic Bone Pathology After Allo-hematopoietic Stem Cell Transplantation in Patients with Inborn Errors of Immunity

PURPOSE

There is a lack of data on post-HSCT non-osteopenic bone pathology specifically for children with inborn errors of immunity (IEI). We collected data on non-osteopenic bone pathology in children with IEI post-HSCT over two decades in a large tertiary pediatric immunology center.

METHODS

Descriptive study with data analysis of bone pathology in allo-HSCT for IEI was performed between 1/1/2000 to 31/12/2018 including patients alive at follow-up to July 2022. Records were analyzed for bone pathology and risk factors. Exclusion criteria included isolated reduced bone density, fractures, and skeletal anomalies due to underlying IEI and short stature without other bone pathology. Bone pathologies were divided into 5 categories: bone tumors; skeletal dysplasia; avascular necrosis; evolving bone deformities; slipped upper femoral epiphysis.

RESULTS

A total of 429 children received HSCT between 2000 and 2018; 340 are alive at last assessment. Non-osteopenic bone pathology was observed post-HSCT in 9.4% of patients (32/340, mean 7.8 years post-HSCT). Eleven patients (34%) had > 1 category of bone pathology. Seventeen patients (17/32; 53%) presented with bilateral bone pathology. The majority of patients received treosulfan-based conditioning (26/32; 81.2%). Totally, 65.6% (21/32) of patients had a history of prolonged steroid use (> 6 months). Pain was the presenting symptom in 66% of patients, and surgical intervention was required in 43.7%. The highest incidence of bone pathologies was seen in Wiskott-Aldrich syndrome (WAS) (n = 8/34; 23.5%) followed by hemophagocytic lymphohistiocytosis patients (n = 3/16; 18.8%).

CONCLUSION

Non-osteopenic bone pathology in long-term survivors of allo-HSCT for IEI is not rare. Most patients did not present with complaints until at least 5 years post-HSCT highlighting the need for ongoing bone health assessment for patients with IEI. Children presenting with stunted growth and bone pathology post-HSCT should undergo skeletal survey to rule out development of post-HSCT skeletal dysplasia. Increased rates and complexity of bone pathology were seen amongst patients with Wiskott-Aldrich syndrome.

Severe, life-threatening, and fatal chronic health conditions after allogeneic blood or marrow transplantation in childhood

BACKGROUND

A comprehensive assessment of morbidity after allogeneic bone marrow transplantation (BMT) performed in childhood remains understudied.

METHODS

Seven hundred eighty-nine allogeneic BMT recipients who had survived ≥2 years after BMT performed between 1974 and 2014 at age <22 years and 690 siblings completed a 255-item survey self-reporting sociodemographics and chronic health conditions. A severity score (grade 3 [severe], 4 [life-threatening], or 5 [fatal]) was assigned to the conditions using Common Terminology Criteria for Adverse Events, version 5.0. For the BMT cohort, the cumulative incidence of chronic health conditions was calculated as a function of time from BMT. Proportional subdistribution hazards models were used to determine predictors of grade 3-5 conditions. Logistic regression was used to estimate the risk of grade 3-4 conditions in BMT recipients who were alive at the time of this study compared with siblings.

RESULTS

The median age at transplantation was 11.3 years (range, 0.4-22.0 years), and the median length of follow-up was 11.7 years (range, 2.0-45.3 years). The most prevalent primary diagnoses were acute lymphoblastic leukemia (30.7%), and acute myeloid leukemia/myelodysplastic syndrome (26.9%). At age 35 years, the cumulative incidence of a grade 3-4 condition was 53.8% (95% CI, 46.7%-60.3%). The adjusted odds ratio of a grade 3-4 condition was 15.1 in survivors (95% CI, 9.5-24.0) compared with siblings. The risk of a grade 3-5 condition increased with age at BMT (hazard ratio [HR], 1.03; 95% CI, 1.01-1.05) and was higher among females (HR, 1.27; 95% CI, 1.02-1.59), patients who received total body irradiation (HR, 1.71; 95% CI, 1.27-2.31), and those reporting chronic graft-versus-host disease (HR, 1.38; 95% CI, 1.09-1.74).

CONCLUSIONS

Two-year survivors of allogeneic BMT in childhood have an increased risk of grade 3-4 chronic health conditions compared with siblings, suggesting the need for long-term follow-up.

Does Diabetes Mellitus Increase the Risk of Avascular Osteonecrosis? A Systematic Review and Meta-Analysis

Avascular osteonecrosis (AVN) is caused by the disrupted blood supply to the bone. Most AVN cases occur in the femoral head, but other sites might be affected as well, including the jaw or distal bones of the extremities. Previous studies suggested that diabetes could increase the risk of AVN of the jaw, but the relationship between diabetes and AVN in other bone sites is unclear. This systematic review and meta-analysis aimed to summarize the evidence from studies that had reported on the occurrence of AVN in sites other than the jaw, depending on the diagnosis of diabetes. Overall, we included 6 observational studies carried out in different populations: primary or secondary AVN of the femoral head, Takayasu arteritis, general population, kidney transplant recipients, systemic lupus erythematosus, and primary brain tumors. A random-effects meta-analysis showed that the risk of AVN in sites other than the jaw was non-significantly increased in patients with diabetes (odds ratio: 1.90, 95% confidence interval: 0.93-3.91). The pooled estimate increased and was significant after the exclusion of one study (2.46, 1.14-5.32). There was a significant heterogeneity (I² = 65%, tau² = 0.48, p = 0.01; prediction interval, 0.21-16.84). There was no significant publication bias (p = 0.432). In conclusion, diabetes could increase the risk of AVN in sites other than the jaw, but the available evidence is limited. There is a need for large, well-designed, population-based studies.

Avascular Necrosis of Femoral Head-Overview and Current State of the Art

Avascular necrosis (AVN) of the femoral head is caused by disruption of the blood supply to the proximal femur. The alterations in the blood supply may occur following a traumatic event or result from a non-traumatic cause. Femoral neck fracture and hip dislocation and associated surgical procedures, corticosteroid therapy, and alcohol abuse frequently lead to AVN development. Type of fracture (displaced or undisplaced) and time between injury and surgery are the most critical factors in assessing the risk of developing AVN. Diagnosis of AVN can be established based on patients’ complaints, medical history, and radiographic findings. There is no consensus on the treatment of patients with AVN to date. Non-surgical methods are dedicated to patients in the early pre-collapse stages of the disease and consist of pharmacotherapy and physiotherapy. Surgery is recommended for patients with advanced disease.

Osteonecrosis in Korean Paediatric and Young Adults with Acute Lymphoblastic Leukaemia or Lymphoblastic Lymphoma: A Nationwide Epidemiological Study

Osteonecrosis (ON) is a serious complication of acute lymphocytic leukaemia (ALL) or lymphoblastic lymphoma (LBL) treatment, and there is little information regarding ON in Korean paediatric and young adult patients. This retrospective cohort study assessed the cumulative incidence of and risk factors for ON using national health insurance claims data from 2008 to 2019 in 4861 ALL/LBL patients. The Kaplan–Meier method was used to estimate the cumulative incidence of ON according to age groups; the Cox proportional hazard regression model was used to identify risk factors related to ON development after diagnosing ALL/LBL. A cause-specific hazard model with time-varying covariates was used to assess the effects of risk factors. Overall, 158 (3.25%) patients were diagnosed with ON, among whom 23 underwent orthopaedic surgeries. Older age, radiotherapy (HR = 2.62, 95% confidence interval (CI) 1.87–3.66), HSCT (HR = 2.40, 95% CI 1.74–3.31), steroid use and anthracycline use (HR = 2.76, CI 1.85–4.14) were related to ON in the univariate analysis. In the multivariate analysis, age and steroid and asparaginase use (HR = 1.99, CI 1.30–3.06) were factors associated with ON. These results suggest that Korean patients with ALL/LBL who used steroids and asparaginase should be closely monitored during follow-up, even among young adult patients.

Understanding the Process and Challenges for Return-to-Work Post-Hematopoietic Cell Transplantation from a Musculoskeletal Perspective: A Narrative Review

The current paper seeks to inform healthcare professionals on how adapting various components of return to work (RTW) programs that are already in use by other musculoskeletal rehabilitation settings can help optimize return to work process for patients with or without musculoskeletal manifestations, posthematopoietic cell transplantation. Since there is no universally agreed RTW structure for hematopoietic cell transplant patients, a narrative approach has been taken utilizing evidence from the existing musculoskeletal return to work assessment publications to help draw parallel for the hematopoietic cell transplant patients. Databases were searched including PUBMED, CINHAL, AMED, SCOPUS, and Cochrane using keywords RTW, functional restoration program, hematopoietic cell transplant, bone marrow transplant, stem cell transplant, and musculoskeletal functional assessment. The authors have managed to outline and propose a structured RTW assessment and monitoring program which can aid in getting patients back to employment by utilizing the functional capacity and job evaluation to help hematopoietic cell transplantation patients reintegrate socially. Patients undergoing hematopoietic cell transplant require additional support and a robust assessment system to allow safe RTW. The proposed model of RTW assessment can prove to be beneficial in helping patients return to work safely. Clinical Significance. To acknowledge the individuality in functional limitation is important in determining not only the rehab needs but also the RTW capabilities. The proposed RTW plan not only promotes an individualized approach to patients but also provides a structure for return to work assessments for hematopoietic cell transplantation patients, thus, eliminating the need for guess work by healthcare professionals. In line with the International Classification of Functioning, Disability, and Health (ICF) recommendations, a RTW assessment combined with a job evaluation helps healthcare professionals and stakeholders to understand the unique challenges and strengths of a patient and thereby design an individualized therapy approach.

Biobehavioral Research and Hematopoietic Stem Cell Transplantation: Expert Review from the Biobehavioral Research Special Interest Group of the American Society for Transplantation and Cellular Therapy

Hematopoietic stem cell transplantation (HCT) is a potentially curative treatment for many hematologic conditions. Despite advances in conditioning and supportive measures, however, there remain significant comorbidities that threaten survivorship. Adverse effects of stress-related biobehavioral processes-defined here as the interactions of behavioral, psychological, and socioenvironmental factors with biology-impact immune recovery and function and are particularly salient in the HCT context, given the importance of immune reconstitution for improved survivorship. However, biobehavioral processes have been underinvestigated in this vulnerable group compared with other cancer populations. Here the Biobehavioral Research Special Interest Group (SIG) of the American Society for Transplantation and Cellular Therapy provides an expert review to inform research directions explicating the biological correlates of behavioral symptoms and evaluate the impact of these on HCT outcomes. The goal of this expert review is to provide a foundation for advancing science that effectively integrates behavioral and biological processes to optimize quality of life and improve clinical outcomes for HCT recipients.

Moderate-severe grade of chronic graft versus host disease and younger age (less than 45 years old) are risk factors for avascular necrosis in adult patients undergoing allogeneic hematopoietic cell transplantation

Avascular necrosis (AVN) is a debilitating complication of allogeneic hematopoietic cell transplantation (HCT). A retrospective review of 845 patients who underwent HCT was conducted. Cumulative incidence of AVN was 6.3% at 4 years. The following risk factors were significantly associated with AVN risk on univariate analysis: age < 45 (p=0.004), moderate to severe chronic GvHD (p<0.001), reduced intensity conditioning (p=0.02), and a diagnosis of acute leukemia (p=0.045). Multivariate analysis confirmed two risk factors: younger age (<45 years), 9.0% vs 4.4% (p=0.011, hazard ratio (HR) 2.134), and moderate-severe chronic GvHD, 15.4% vs 2.1% (p<0.001, HR 4.950). A risk score model was generated assigning a score to each risk factor. A score of 1 was assigned to moderate-severe GvHD or those with age <45. Total score was calculated, thus dividing patient into three groups: low (score 0, n=349, 41.3%), intermediate (score 1, n=379, 44.9%), and high risk (score 2; n=116, 13.7%). This risk score could stratify the patients according to AVN risk (p<0.001). The risk of AVN was 1.5% in the low risk, 6.2% in the intermediate risk, and 20.8% in the high risk groups. Moderate-severe chronic GvHD and younger age (<45 years) are key risk factors for AVN following allogeneic HCT.

Late Effects After Haematopoietic Stem Cell Transplantation in ALL, Long-Term Follow-Up and Transition: A Step Into Adult Life

Haematopoietic stem cell transplant (HSCT) can be a curative treatment for children and adolescents with very-high-risk acute lymphoblastic leukaemia (ALL). Improvements in supportive care and transplant techniques have led to increasing numbers of long-term survivors worldwide. However, conditioning regimens as well as transplant-related complications are associated with severe sequelae, impacting patients' quality of life. It is widely recognised that paediatric HSCT survivors must have timely access to life-long care and surveillance in order to prevent, ameliorate and manage all possible adverse late effects of HSCT. This is fundamentally important because it can both prevent ill health and optimise the quality and experience of survival following HSCT. Furthermore, it reduces the impact of preventable chronic illness on already under-resourced health services. In addition to late effects, survivors of paediatric ALL also have to deal with unique challenges associated with transition to adult services. In this review, we: (1) provide an overview of the potential late effects following HSCT for ALL in childhood and adolescence; (2) focus on the unique challenges of transition from paediatric care to adult services; and (3) provide a framework for long-term surveillance and medical care for survivors of paediatric ALL who have undergone HSCT.

Pain Management in Childhood Leukemia: Diagnosis and Available Analgesic Treatments

Pain is one of the most common symptoms in children suffering from leukemia, who are often misdiagnosed with other childhood painful diseases such as juvenile idiopathic arthritis. Corticosteroid-induced osteonecrosis (ON) and vincristine-induced peripheral neuropathy (VIPN) are the most common painful manifestations. Additionally, ongoing pain may continue to impact quality of life in survivorship. This narrative review focuses on the pathophysiological mechanisms of pain in childhood leukemia and current available indications for analgesic treatments. Pain management in children is often inadequate because of difficulties in pain assessment, different indications across countries, and the lack of specific pediatric trials. Analgesic drugs are often prescribed off-label to children by extrapolating information from adult guidelines, with possible increased risk of adverse events. Optimal pain management should involve a multidisciplinary team to ensure assessment and interventions tailored to the individual patient.

Bone Health Management After Hematopoietic Cell Transplantation: An Expert Panel Opinion from the American Society for Transplantation and Cellular Therapy

Bone health disturbances commonly occur after hematopoietic cell transplantation (HCT) with loss of bone mineral density (BMD) and avascular necrosis (AVN) foremost among them. BMD loss is related to pretransplantation chemotherapy and radiation exposure and immunosuppressive therapy for graft-versus-host-disease (GVHD) and results from deficiencies in growth or gonadal hormones, disturbances in calcium and vitamin D homeostasis, as well as osteoblast and osteoclast dysfunction. Although the pathophysiology of AVN remains unclear, high-dose glucocorticoid exposure is the most frequent association. Various societal treatment guidelines for osteoporosis exist, but the focus is mainly on menopausal-associated osteoporosis. HCT survivors comprise a distinct population with unique comorbidities, making general approaches to bone health management inappropriate in some cases. To address a core set of 16 frequently asked questions (FAQs) relevant to bone health in HCT, the American Society of Transplant and Cellular Therapy Committee on Practice Guidelines convened a panel of experts in HCT, adult and pediatric endocrinology, orthopedics, and oral medicine. Owing to a lack of relevant prospective controlled clinical trials that specifically address bone health in HCT, the answers to the FAQs rely on evidence derived from retrospective HCT studies, results extrapolated from prospective studies in non-HCT settings, relevant societal guidelines, and expert panel opinion. Given the heterogenous comorbidities and needs of individual HCT recipients, answers to FAQs in this article should be considered general recommendations, with good medical practice and judgment ultimately dictating care of individual patients. Readers are referred to the Supplementary Material for answers to additional FAQs that did not make the core set.

Bone health in childhood cancer: review of the literature and recommendations for the management of bone health in childhood cancer survivors

In the past decades, new cancer treatment approaches for children and adolescents have led to a decrease in recurrence rates and an increase in long-term survival. Recent studies have focused on the evaluation of the late effects on bone of pediatric cancer-related treatments, such as chemotherapy, radiation and surgery. Treatment of childhood cancer can impair the attainment of peak bone mass, predisposing to premature onset of low bone mineral density, or causing other bone side-effects, such as bone quality impairment or avascular necrosis of bone. Lower bone mineral density and microarchitectural deterioration can persist during adulthood, thereby increasing fracture risk. Overall, long-term follow-up of childhood cancer survivors is essential to define specific groups at higher risk of long-term bone complications, identify unrecognized long-term adverse effects, and improve patient care. Children and adolescents with a cancer history should be carefully monitored, and patients should be informed of possible late complications of their previous medical treatment. The International Osteoporosis Foundation convened a working group to review the bone complications of pediatric cancer survivors, outlining recommendations for the management of bone health, in order to prevent and treat these complications.

Lower limb pain following allogeneic hematopoietic stem cell transplantation in Japanese children

BACKGROUND

Patients who undergo allogeneic hematopoietic stem cell transplantation (allo-HSCT) can experience musculoskeletal pains in their lower limbs in the early and late post-transplantation period. This study investigated demographics and clinical characteristics of the lower limb pain (LLP) among Japanese survivors of pediatric allo-HSCT.

METHODS

A total of 143 consecutive Japanese patients who had undergone allo-HSCT less than 18 years of age in a single institute between 2005 and 2015 were reviewed. Patients referred for in-house orthopedic evaluation of their sustained LLPs that impaired ambulation were defined as LLP group. Illness/transplantation-related parameters were compared between LLP group and non-LLP group.

RESULTS

Ninety children with a mean age of 8.5 years at transplantation were enrolled. Their median follow-up period following transplantation was 6.3 years (range, 2.1-12.5). There were four patients in LLP group, whose etiologies were AVN of the femoral head and insufficiency fracture (ISF) of the tibia or the medial cuneiform bone. Cumulative dose of steroids that administered from six months before transplantation to six months after discharge from hospitalization for transplantation was significantly higher in LLP group than non-LLP group. Additionally, the two groups differed significantly in terms of hospitalization period after transplantation. LLP caused by AVN of the femoral head manifested between six months and two years, whereas that caused by ISF within the first six months after transplantation.

CONCLUSIONS

The incidence of sustained LLP that impairs ambulation following contemporary allo-HSCT is not common in Japanese pediatric survivors. The risk of developing musculoskeletal LLP may increase with a higher steroid dosage in the peri-transplant period. LLP caused by AVN of the femoral head is likely to manifest later than that caused by ISF.

The Impact of Donor Type on Long-Term Health Status and Quality of Life after Allogeneic Hematopoietic Stem Cell Transplantation for Childhood Acute Leukemia: A Leucémie de l'Enfant et de L'Adolescent Study

We compared the long-term impact of donor type (sibling donor [SD] versus matched unrelated donor [MUD] or umbilical cord blood [UCB]) on late side effects and quality of life (QoL) in childhood acute leukemia survivors treated with hematopoietic stem cell transplantation. We included 314 patients who underwent transplantation from 1997 to 2012 and were enrolled in the multicenter French Leucémie de l'Enfant et de L'Adolescent ("Leukemia in Children and Adolescents") cohort. More than one-third of the patients were adults at last visit; mean follow-up duration was 6.2 years. At least 1 late effect was observed in 284 of 314 patients (90.4%). The average number of adverse late effects was 2.1 ± .1, 2.4 ± .2, and 2.4 ± .2 after SD, MUD, and UCB transplantation, respectively. In a multivariate analysis, considering the SD group as the reference, we did not detect an impact of donor type for most sequelae, with the exception of increased risk of major growth failure after MUD transplantation (odds ratio [OR], 2.42) and elevated risk of osteonecrosis after UCB transplantation (OR, 4.15). The adults and children's parents reported comparable QoL among the 3 groups. Adult patient QoL scores were lower than age- and sex-matched French reference scores for almost all dimensions. We conclude that although these patients are heavily burdened by long-term complications, donor type had a very limited impact on their long-term health status and QoL.

Late Effects Surveillance Recommendations among Survivors of Childhood Hematopoietic Cell Transplantation: A Children's Oncology Group Report

Hematopoietic cell transplantation (HCT) is an important curative treatment for children with high-risk hematologic malignancies, solid tumors, and, increasingly, nonmalignant diseases. Given improvements in care, there are a growing number of long-term survivors of pediatric HCT. Compared with childhood cancer survivors who did not undergo transplantation, HCT survivors have a substantially increased burden of serious chronic conditions and impairments involving virtually every organ system and overall quality of life. This likely reflects the joint contributions of pretransplantation treatment exposures and organ dysfunction, the transplantation conditioning regimen, and any post-transplantation graft-versus-host disease (GVHD). In response, the Children's Oncology Group (COG) has created long-term follow-up guidelines (www.survivorshipguidelines.org) for survivors of childhood, adolescent, and young adult cancer, including those who were treated with HCT. Guideline task forces, consisting of HCT specialists, other pediatric oncologists, radiation oncologists, organ-specific subspecialists, nurses, social workers, other health care professionals, and patient advocates systematically reviewed the literature with regards to late effects after childhood cancer and HCT since 2002, with the most recent review completed in 2013. For the most recent review cycle, over 800 articles from the medical literature relevant to childhood cancer and HCT survivorship were reviewed, including 586 original research articles. Provided herein is an organ system-based overview that emphasizes the most relevant COG recommendations (with accompanying evidence grade) for the long-term follow-up care of childhood HCT survivors (regardless of current age) based on a rigorous review of the available evidence. These recommendations cover both autologous and allogeneic HCT survivors, those who underwent transplantation for nonmalignant diseases, and those with a history of chronic GVHD.