Thyroid abnormalities in survivors of childhood cancer

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.

Hodgkin Lymphoma in Children and Adolescents of Northern Greece: 25-Year Results and Long-term Follow-up

Aim of this study was to evaluate the long-term therapeutic outcome and treatment-related complications in Hodgkin disease. We reviewed the medical records of 93 patients diagnosed with classic Hodgkin lymphoma, treated, and followed-up during the last 25 years. The cohort study included 49 males and 44 females with median age 11.8 years old (range: 3.95 to 17.42 y). The most common subtype was nodular sclerosis in 47/93 (50.5%). B symptoms were present in 15/93 (16.1%). From January 2009 until December 2020, 55 (59%) patients diagnosed with Hodgkin lymphoma were treated according to European Network for Pediatric Hodgkin Lymphoma (EURONET)-PHL-C1 protocol. Concerning outcome, a total of 89/93 patients are alive. Relapse occurred in 7/93. Second malignancies are reported in a total of 5 patients, 3 solid tumors (thyroid cancer, breast cancer, and osteosarcoma), and 2 acute myeloid leukemias. The overall survival and event-free survival for the whole cohort were 95.7% and 83.9%, respectively. Disease-free survival was 92.5%. Although a considerable high fraction of patients with Hodgkin disease can achieve continuous complete remission, they are at a high risk of developing long-term treatment-related complications. High curative rates as well as prevention of late effects can be achieved by implementation of individualized treatment strategies and innovative treatments.

Characteristics and clinical course of thyroid abnormalities arisen in long term survivors of childhood cancer

BACKGROUND

Thyroid abnormality is a common late effect seen in childhood cancer survivors (CCSs). We analyzed the prevalence and risk factors of thyroid abnormalities based on diagnoses and treatment modalities in CCSs.

METHODS

The medical records of 257 CCSs who were diagnosed with cancer less than 20 year of age were retrospectively reviewed. The median age was 11.8 years (0.1-19.8). The median follow-up period after completion of therapy was 9.6 years (5.0-19.5).

RESULTS

Of 257 subjects, thyroid abnormalities were identified in 107 (41.6%). Sixty-five out of 257 (25.3%) had subclinical hypothyroidism, and 16 (6.2%) developed central hypothyroidism. Five CCSs (1.9%) had primary overt hypothyroidism. Five (1.9%) and 6 (2.3%) CCSs were diagnosed with autoimmune thyroiditis and thyroid cancer, respectively. Among the different diagnostic groups, thyroid abnormalities were frequent in the brain tumor or Hodgkin disease or nasopharyngeal cancer groups. CCSs who received irradiation directly or near hypothalamus-pituitary-thyroid (HPT) axis had more thyroid abnormalities compared to the rest CCSs (P < 0.0001). CCSs who were treated with SCT had an increased prevalence of thyroid abnormalities (60.5%) compared to the other CCSs (37.9%) (P = 0.0069). Forty-five (42%) of 107 subjects with thyroid abnormalities had normalized thyroid hormone levels at the last follow-up. Irradiation directly or near HPT axis were thought to be a predicting factor of persistent subclinical hypothyroidism.

CONCLUSIONS

Subclinical hypothyroidism was common in CCSs. CCSs with irradiation directly or near HPT axis were at risk for persistent thyroid dysfunction.

Late side effects of cancer treatment in childhood cancer survivors

INTRODUCTION

Childhood cancers are usually treated with chemotherapy and radiation. Therefore, understanding the late side effects of such treatments is important to improve the quality of life in childhood cancer survivors. The present study aimed to investigate the late complications of treatments in childhood cancer survivors.

METHODS

This study is a retrospective descriptive study. A total number of 93 cases were enrolled in this study. These cases had a history of childhood cancer documented in their medical records at the Shafa Hospital, Ahvaz, Iran. The age range was 5.9-21.3 years and included 62 males and 31 female patients.

RESULTS

Many of the patients at this hospital with childhood cancer had experienced chemotherapy side effects as well as late effects of cancer therapy. Hypothyroidism is a late complication of therapy in thoracic cancers and head/neck tumors with relative frequencies of 23.1% and 12.5%, respectively. Scoliosis was observed in the patients undergoing the ABVD + COPP and 8/1 regimens with relative frequencies of 4% and 50%, respectively. Lower growth percentiles were also late side effects of cancer therapy. The highest relative frequency of growth retardation was observed in the <5 age group (46.7%). Restrictive lung changes had an overall relative frequency of 6.5% in male patients with all types of tumors. Sensorineural hearing loss was observed in patients with leukemia and Hodgkin lymphoma with relative frequencies of 8.7% and 24.0, respectively.

CONCLUSION

The occurrence of most side effects could be decreased through early diagnosis, dose adjustment of some drugs, and preventative measures.

Prevalence of thyroid malignancy and hormonal dysfunction following radiation exposure in childhood

INTRODUCTION

Childhood radiation exposure is a known risk factor for thyroid malignancy and dysfunction. However, local data are limited and there is no consensus on the modality and frequency of screening in this high-risk group.

METHODS

Retrospective analysis study evaluating patients with childhood radiation exposure in 2006-2016 and minimum of 1-year follow-up.

RESULTS

Of the 132 childhood cancer survivors in the study, thyroid malignancy was detected in 2 cases (1.5%) and thyroid nodules in 13 (9.8%). The earliest thyroid malignancy was detected 5 years post-radiotherapy via ultrasound. Of the 84 patients who had screening thyroid function test, 26 (31.0%) were detected with abnormal test results post-radiation, majority being subclinical hypothyroidism.

CONCLUSION

Regular screening via clinical examination for thyroid nodules should be performed at least annually. Where feasible and if resources permit, consideration should be given to using ultrasound for thyroid nodule(s) and malignancy screening at 5 years post-radiation therapy. Screening for thyroid dysfunction can be considered from 6-12 months post-radiotherapy.

Endocrine Sequelae in Childhood Cancer Survivors

The 5-year survival rate for childhood cancer survivors is currently greater than 80% in developed countries. However, survivors may have an increased risk of endocrine toxicities from their tumors or their treatments. Although some endocrinopathies are apparent soon after cancer therapy completion, others manifest years later; therefore, long-term surveillance is crucial. This article reviews the association between cancer treatments and endocrine late effects. It also summarizes recommendations regarding surveillance for endocrine late effects and referrals to endocrinologists based on treatment exposures. In addition, this article provides special considerations for the treatment of endocrinopathies in survivors.

Thyroid Sequelae of Pediatric Cancer Therapy

The hypothalamic-pituitary-thyroid axis is a common site of unintended, acquired disease either during or after the treatment of cancer. Children treated with external radiation therapy are at the highest risk for developing a thyroid-related late effect, but thyroid dysfunction and second primary thyroid neoplasms can also occur after treatment with radiopharmaceutical agents such as 131I-metaiodobenzylguanidine. Increasingly recognized is the development of early thyroid dysfunction as an off-target consequence of the more novel cancer therapeutics such as the tyrosine kinase inhibitors and immune checkpoint inhibitors. Thyroid sequelae resulting from irradiation may manifest only after years to decades of follow-up, and their resultant clinical symptoms may be indolent and non-specific. Therefore, lifelong monitoring of the childhood cancer survivor at risk for thyroid disease is paramount. In this comprehensive review, the myriad thyroid adverse effects resulting from pediatric cancer treatment are discussed and an overview of screening and treatment of these thyroid sequelae provided.

Metabolic Disturbances in Children Treated for Solid Tumors

Metabolic disturbances are among the most common disorders diagnosed in pediatric patients after anti-cancer therapy (ACT). The aim of our study was to evaluate the prevalence of metabolic disturbances among patients after ACT. The study group comprised 44 patients (31 boys) treated for solid tumors and 31 patients in the control group. Body weight, height, body mass index (BMI) values, lipid parameters are expressed in Standard Deviation Score (SDS), based on centile charts. Indicators of risk to atherosclerosis were calculated. Obesity/overweight was observed in one third of the patients. Hypercholesterolemia occurred in half of them, elevated tryglicerides (TG) SDS in 11, and elevated low-density lipoprotein cholesterol (LDL-C) SDS in nine of the patients. Increased levels of both cholesterol SDS and LDL SDS were found in nine patients and four of them also showed elevated levels of TG SDS. There were significant differences in lipid parameters between the sexes. Risk indicators of lipid disorders defined by statistical distances (τ) were determined for the study group and the control group. The sum of the risk ratios of lipid disorders in the study group was 150 times higher than in the control group. Patients after ACT require special monitoring of lipids profiles and thyroid function as they are at higher risk for dyslipidemia and atherosclerosis than healthy people.

Central hypothyroidism in a pediatric case of primary acute monoblastic leukemia with central nervous system infiltration: A case report

RATIONALE

Central nervous system (CNS) leukemia is a frequent diagnosis in pediatric acute myeloblastic leukemia (AML) and includes neural symptoms. However, CNS leukemia is rarely associated with central hypsothyroidism.

PATIENT CONCERNS AND DIAGNOSES

A 2-year-old female with AML with MLL rearrangement presented with CNS infiltration. Laboratory tests suggested the presence of central hypothyroidism (thyroid-stimulating hormone [TSH]: 0.48 mIU/ml, normal range 0.7-6.4 mIU/ml; serum free thyroxine [FT4]: 0.62 ng/dl, normal range 0.8-2.2 ng/dl; free triiodothyronine: 1.57 pg/ml, normal range 2.7-5.6 pg/ml). Magnetic resonance imaging detected no lesions in the hypothalamus, pituitary, or thyroid.

INTERVENTIONS AND OUTCOMES

Levothyroxine (2.5 mg/kg/day) was administered together with chemotherapy and intrathecal injection of methotrexate, cytarabine, and hydrocortisone into the cerebrospinal fluid. The FT4 concentration increased after levothyroxine treatment, but later decreased after relapse of CNS leukemia. The TSH concentrations remained low. After remission of CNS leukemia, the TSH and FT4 concentrations quickly recovered to their normal ranges.

LESSONS

We believe that the CNS leukemia directly affected TSH and thyroid hormone secretion in our patient.

Development of Metabolic Syndrome Associated to Cancer Therapy: Review

Long-term childhood cancer survivors are at great risk of developing late adverse effects after treatment, such as, reduced growth, obesity, decreased fertility, high blood pressure, cardiovascular diseases, impaired glucose, another form of cancer, among others organ dysfunctions, some of them are part of the metabolic syndrome. Metabolic syndrome and cancer connection is still not entirely understood, but there are some notions about it. Metabolic alterations produced during childhood cancer are more likely determined by treatments like radiotherapy, chemotherapy, glucocorticoids therapy, and surgery. Cancer treatment is associated to vascular alterations, hormone deficiencies, changes in insulin sensitivity, lipid metabolism, and inflammatory mediators. Obesity has been considered a crucial component in metabolic syndrome; obesity risk factors during childhood cancer include cranial radiation, female gender, and exposure to glucocorticoids such as dexamethasone. In addition, local radiotherapy or surgery may cause endocrine deficiencies, depends on the directly damage of endocrine organs. Patients who received some types of cancer treatment should be evaluated periodically to early diagnostic metabolic disorders associated to antineoplastic therapy.

Risk factors for subsequent endocrine-related cancer in childhood cancer survivors

Long-term adverse health conditions, including secondary malignant neoplasms, are common in childhood cancer survivors. Although mortality attributable to secondary malignancies declined over the past decades, the risk for developing a solid secondary malignant neoplasm did not. Endocrine-related malignancies are among the most common secondary malignant neoplasms observed in childhood cancer survivors. In this systematic review, we describe risk factors for secondary malignant neoplasms of the breast and thyroid, since these are the most common secondary endocrine-related malignancies in childhood cancer survivors. Radiotherapy is the most important risk factor for secondary breast and thyroid cancer in childhood cancer survivors. Breast cancer risk is especially increased in survivors of Hodgkin lymphoma who received moderate- to high-dosed mantle field irradiation. Recent studies also demonstrated an increased risk after lower-dose irradiation in other radiation fields for other childhood cancer subtypes. Premature ovarian insufficiency may protect against radiation-induced breast cancer. Although evidence is weak, estrogen-progestin replacement therapy does not seem to be associated with an increased breast cancer risk in premature ovarian-insufficient childhood cancer survivors. Radiotherapy involving the thyroid gland increases the risk for secondary differentiated thyroid carcinoma, as well as benign thyroid nodules. Currently available studies on secondary malignant neoplasms in childhood cancer survivors are limited by short follow-up durations and assessed before treatment regimens. In addition, studies on risk-modifying effects of environmental and lifestyle factors are lacking. Risk-modifying effects of premature ovarian insufficiency and estrogen-progestin replacement therapy on radiation-induced breast cancer require further study.

Ultrasound Evaluation of Thyroid Gland Pathologies After Radiation Therapy and Chemotherapy to Treat Malignancy During Childhood

PURPOSE

The purpose of this study was to evaluate correlations between treatment of malignancy by radiation therapy during childhood and the occurrence of thyroid gland pathologies detected by ultrasonography in follow-up examinations.

METHODS AND MATERIALS

Reductions of thyroid gland volume below 2 standard deviations of the weight-specific mean value, occurrence of ultrasonographically detectable thyroid gland pathologies, and hypothyroidism were retrospectively assessed in 103 children and adolescents 7 months to 20 years of age (median: 7 years of age) at baseline (1997-2013) treated with chemoradiation therapy (with the thyroid gland dose assessable) or with chemotherapy alone and followed by ultrasonography and laboratory examinations through 2014 (median follow-up time: 48 months).

RESULTS

A relevant reduction of thyroid gland volume was significantly correlated with thyroid gland dose in univariate (P<.001) and multivariate analyses for doses above 2 Gy. Odds ratios were 3.1 (95% confidence interval: 1.02-9.2; P=.046) for medium doses (2-25 Gy) and 14.8 (95% confidence interval: 1.4-160; P=.027) for high doses (>25 Gy). Thyroid gland dose was significantly higher in patients with thyroid gland pathologies during follow-up (P=.03). Univariate analysis revealed significant correlations between hypothyroidism and thyroid gland dose (P<.001).

CONCLUSIONS

Ultrasonographically detectable changes, that is, volume reductions, pathologies, and hypothyroidism, after malignancy treatment during childhood are associated with thyroid gland dose. Both ultrasonography and laboratory follow-up examinations should be performed regularly after tumor therapy during childhood, especially if the treatment included radiation therapy.