Predictive factors for thyroid complications after radiation therapy-data from a cohort of cancer patients closely followed since they were irradiated

Thyroid abnormalities in patients with Hodgkin lymphoma: The importance of close surveillance

INTRODUCTION

Survival in paediatric patients with Hodgkin lymphoma (HL) has increased over the last decades. However, these patients are at increased risk of developing late thyroid sequelae due to the treatment with irradiation and alkylating agents.

METHODS

We conducted an observational and retrospective study in patients with a diagnosis of HL between 2007 and 2022, in a hospital that is a paediatric oncology reference centre, through the review of electronic health records. We collected data on demographic (age, sex), clinical, radiological and histopathological variables, the dosage of alkylating agents and radiotherapy (RT) and on thyroid disorders using Microsoft Excel. The data analysis was conducted with SPSS version 17, using the Fisher exact test for qualitative data, a nonparametric test for quantitative data and Kaplan-Meier curves.

RESULTS

Sixty patients received a diagnosis of HL from 2007 to 2022. The median duration of follow-up was 78.5 months. There were 4 detected cases of hypothyroidism, 5 of thyroid nodules and 1 of subclinical hyperthyroidism. Treatment with RT was significantly associated with the development of hypothyroidism (P= .026), thyroid nodules (P= .01) and thyroid disease overall (P= .003). We estimated that the risk of thyroid disease increased 8-fold with each additional Grey received (hazard ratio, 1.081; 95% CI, 1.014-1.152; P= .017).

CONCLUSION

Hodgkin lymphoma patients treated with RT are at increased risk of late thyroid disorders, mainly hypothyroidism and malignancy. This risk is greater the higher the RT dosage and the longer the follow-up. We did not find evidence of an association between the use of alkylating agents and an increase in the risk of thyroid disease.

Current concepts regarding Graves' orbitopathy

Graves' orbitopathy (GO) is an orbital autoimmune disorder and the main extrathyroidal manifestation of Graves' disease, the most common cause of hyperthyroidism. GO affects about 30% of Graves' patients, although fewer than 10% have severe forms requiring immunosuppressive treatments. Management of GO requires a multidisciplinary approach. Medical therapies for active moderate-to-severe forms of GO (traditionally, high-dose glucocorticoids) often provide unsatisfactory results, and subsequently surgeries are often needed to cure residual manifestations. The aim of this review is to provide an updated overview of current concepts regarding the epidemiology, pathogenesis, assessment, and treatment of GO, and to present emerging targeted therapies and therapeutic perspectives. Original articles, clinical trials, systematic reviews, and meta-analyses from 1980 to 2021 were searched using the following terms: Graves' disease, Graves' orbitopathy, thyroid eye disease, glucocorticoids, orbital radiotherapy, rituximab, cyclosporine, azathioprine, teprotumumab, TSH-receptor antibody, smoking, hyperthyroidism, hypothyroidism, thyroidectomy, radioactive iodine, and antithyroid drugs. Recent studies suggest a secular trend toward a milder phenotype of GO. Standardized assessment at a thyroid eye clinic allows for a better general management plan. Treatment of active moderate-to-severe forms of GO still relies in most cases on high-dose systemic-mainly intravenous-glucocorticoids as monotherapy or in combination with other therapies-such as mycophenolate, cyclosporine, azathioprine, or orbital radiotherapy-but novel biological agents-including teprotumumab, rituximab, and tocilizumab-have achieved encouraging results.

Thyroid disorders following hematopoietic stem cell transplantation in childhood: the impact of the conditioning regimen on thyroid dysfunction, volume changes and occurrence of nodules

BACKGROUND

Thyroid late effects are among the most frequent sequelae reported after pediatric hematopoietic stem cell transplantation (HSCT). Though the detrimental effects of radiotherapy on the developing thyroid gland have been extensively assessed, the role of chemotherapy-only conditioning regimens is still controversial.

OBJECTIVE

We aimed at describing the occurrence, monitoring and management of thyroid function disorders (i.e. Graves' disease, Hashimoto thyroiditis and non-autoimmune hypothyroidism), nodules and volumetric changes over a 20-year observation period in a single pediatric transplant unit. In addition, we assessed the impact of different conditioning regimens on thyroid health.

STUDY

design Retrospective observational analysis. The study population included 244 patients transplanted for pediatric malignant or non-malignant diseases between 1999 and 2018 and for whom at least four thyroid function tests and one or more thyroid ultrasound(s) assessed sequentially after HSCT were available.

RESULTS

The 15-year cumulative incidence (CI) of either autoimmune or non-autoimmune thyroid dysfunctions (34%, SE 5.3%) did not statistically differ between total body irradiation- (TBI-) and chemo-based regimens (p 0.23). Indeed, the CI after busulfan (BU) was overall superimposable to that recorded after TBI (10-year CI: 22.2% versus 25.9%, respectively). Nevertheless, the CI of non-autoimmune hypothyroidism was statistically higher after BU- (12.4%, SE 3.7%) than after other chemotherapy only-based-conditionings (3.1%, SE 3.1%; p 0.02, 5-year CI), treosulfan included. The overall CI of nodules was low for the first 5 years after HSCT (1.9%, SE 0.9%), but it showed a subsequent steep increase over time, with a 15-year CI as high as 52.1% (SE 7.5%). TBI-conditioned patients experienced a higher 15-year CI of nodules (66.8%, SE 9.1%) compared to those receiving chemo-only regimens (33.6%, SE 9.5%; p 0.02), whereas age > 10 years upon transplantation showed a protective effect (HR 0.42, 95% confidence interval 0.2-0.88). Finally, a systematic sonographic follow-up highlighted a progressive statistically significant reduction in thyroid antero-posterior diameter among patients conditioned with TBI (p 0.005), but not after chemo-only regimens.

CONCLUSIONS

TBI and younger age upon HSCT play a remarkable and statistically demonstrated detrimental role on the occurrence of thyroid nodules, both benign and malignant. TBI and BU expose patients to a higher cumulative incidence of thyroid dysfunctions than other chemo-only regimens, treosulfan included. Accordingly, BU can be regarded as the most thyrotoxic agent among those administered as a part of a chemo-only conditioning regimen. Finally, patients conditioned with TBI, but not with other regimens, show a progressive decrease in thyroid volume over time, as assessed by sequential ultrasounds.

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

Thyroid disorders (TD) represent a remarkable share of all the late morbidities experienced following pediatric haematopoietic stem cell transplantation (HSCT), with long-term reported occurrence often exceeding 70%. In addition, the data collected on wide cohorts of survivors assessed longitudinally outlined a progressive increase in the cumulative incidence of TD as far as 30 years following transplantation. Accordingly, a life-long monitoring of thyroid health is warranted among patients exposed to HSCT in childhood, in order to early detect TD and undertake a prompt dedicated treatment. Although several national and international consortia have provided recommendations for the early detection of thyroid disorders among childhood cancer survivors exposed to radiotherapy and alkylating agents, no guidelines specifically and thoroughly focused on HSCT-related TD have been published to date. As stem cell transplantation has become the standard-of-care in a growing body of non-oncological conditions, this urge has become pivotal. To highlight the challenging issues specifically involving this cohort of patients and to provide clinicians with the proposal of a practical follow-up protocol, we reviewed published literature in the light of the shared experience of a multidisciplinary team of pediatric oncologists, transplantologists, pathologists and endocrinologists involved in the long-term care of HSCT survivors. As a final result, we hereby present the proposals of a practical and customized risk-based approach to tailor thyroid health follow-up based on HSCT-related detrimental factors.