Thyroid function disorders and secondary cancer following haematopoietic stem cell transplantation in pediatrics: State of the art and practical recommendations for a risk-based follow-up

Long-Term Complications after Allogeneic Hematopoietic Stem Cell Transplantation with Treosulfan- or Busulfan-Based Conditioning in Pediatric Patients with Acute Leukemia or Myelodysplastic Syndrome: Results of an Associazione Italiana Ematologia Oncologia Pediatrica Retrospective Study

Patients undergoing hematopoietic stem cell transplantation (HSCT) for hematologic malignancies during childhood have an increased risk of developing long-term sequelae that are in part attributable to the conditioning regimen. The present study aimed to assess the occurrence of long-term toxicities in a population of children who underwent HSCT for hematologic malignancies using either treosulfan or busulfan in the conditioning regimen. The cumulative incidences of growth impairment, altered gonadal function, altered thyroid function, cataracts, secondary malignant neoplasia, and altered pulmonary function were evaluated retrospectively by univariable and multivariable analyses in a population of 521 pediatric patients with acute leukemias or myelodysplastic syndromes treated in 20 Italian transplant centers affiliated with the Associazione Italiana Ematologia ed Oncologia Pediatrica (AIEOP). The median duration of follow-up for the entire study population was 7.1 years (range, 1 to 16 years). Overall, a larger proportion of patients given busulfan developed long-term toxicities compared to patients treated with treosulfan (34% versus 20%; P = .01). In univariable analysis, gonadal toxicity developed in 10% of patients who received treosulfan (95% confidence interval [CI], 3% to 15%), compared with 38% (95% CI, 24% to 39%) of busulfan-treated patients (P = .02), and this finding was confirmed by multivariable analysis (relative risk, .51; 95% CI, .34 to .76; P = .0009). We did not find any statistically significant associations between the occurrence of other long-term toxicities and the use of either busulfan or treosulfan. This study provides evidence that the use of treosulfan is correlated with a reduced incidence of gonadal toxicity in children undergoing HSCT for hematologic malignancies.

Long-term toxicities after allogeneic hematopoietic stem cell transplantation with or without total body irradiation: a population-based study in Korea

PURPOSE

To compare long-term toxicity incidences, including secondary cancer (SC) with or without total body irradiation (TBI), in Asian patients receiving allogeneic hematopoietic stem cell transplantation (HSCT) using a nationwide database.

MATERIALS AND METHODS

We identified 4,554 patients receiving HSCT for leukemic disease from 2009 to 2016 using the healthcare bigdata system of Korea. Incidence rate ratios (IRRs) for SC, cataracts, hypothyroidism, chronic kidney disease (CKD), myocardial infarction, or strokes were compared, and standardized incidence ratios (SIR) of SC was also estimated.

RESULTS

TBI was conducted on 1,409 patients (30.9%). No overall survival differences based on TBI were observed. With a median follow-up duration of 58.2 months, 143 patients were diagnosed with subsequent SC (3.4%). Incidence rates per 1,000 person-year were 6.56 (95% confidence interval [CI], 4.8-8.8) and 7.23 (95% CI, 5.9-8.8) in the TBI and no-TBI groups, respectively (p = 0.594). Also, the SIR (95% CI) was not significantly increased by TBI (1.32 [0.86-1.94] vs. 1.39 [1.08-1.77] in the no-TBI group). In the young age group (0-19 years), SIRs were increased in both groups regardless of TBI (8.60 vs. 11.96). The IRRs of cataracts (1.60; 95% CI, 1.3-2.0), CKD (1.85; 95% CI, 1.3-2.6), and hypothyroidism (1.50; 95% CI, 1.1-2.1) were significantly increased after TBI. However, there were no significant differences in the occurrence of myocardial infarction and stroke according to TBI.

CONCLUSION

Our results suggest that modern TBI may not additionally increase the risk of SC after allogeneic HSCT, although increased risks of other diseases were noted. Physicians should carefully consider individualized risks and benefits of TBI, with a particular focus by age group.

Global incidence and prevalence of differentiated thyroid cancer in childhood: systematic review and meta-analysis

Objective

Differentiated thyroid cancer (DTC) is rare in childhood and adolescence although it represents the most frequent endocrine malignancy in this population. DTC includes both papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC). Most pediatric DTCs are PTCs, while FTCs are rare. To date, no systematic reviews on the global epidemiology of pediatric and adolescent DTC have been published. This systematic review and meta-analysis aims to estimate the overall incidence and prevalence of DTCs in patients aged 0-19 years.

Methods

The systematic research was conducted from January 2000 to December 2021 through MEDLINE via PubMed, Cochrane Library, and Embase databases. Two separate meta-analyses were performed for PTC and FTC.

Results

After the selection phase, a total of 15 studies (3,332 screened) met the inclusion criteria and are reported in the present systematic review. Five studies were conducted in Europe, five in North America, two in South America, one in Asia, one reported data for 49 countries and territories across the five continents, and one from both the USA and Africa. Most of the studies (n = 14) reported data obtained from national registries, and only one provided information collected from hospital medical records. Beyond the actual trend over time, our study reported a pooled global incidence rate (IR) of PTC and FTC in the pediatric age of 0.46 (95% CI: 0.33-0.59) and 0.07 (95% CI: 0.02-0.12) per 100,000 person-years, respectively. The highest IRs were recorded among Caucasian girls, and the lowest in black or other races/ethnicities.

Conclusion

Our data confirm that DTC in the pediatric population is a rare condition. The pooled IRs of the studies included in this meta-analysis are ~0.5 for PTC, which is the most common histological type when both genders and all age groups are considered. The implementation of a prospective international registry on pediatric DTC, as part of the wider European Registries for Rare Endocrine Conditions, has been recently proposed. In addition to providing relevant information on the clinical behavior of this rare disease, standardization of data collection will be pivotal to fill current gaps and allow an accurate estimation of the real incidence and risk factors of DTC.