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

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.

Links between Breast and Thyroid Cancer: Hormones, Genetic Susceptibility and Medical Interventions

Breast and thyroid glands are two common sites of female malignancies. Since the late 19th century, physicians have found that the cancers in either thyroid or mammary gland might increase the risk of second primary cancers in the other site. From then on, many observational clinical studies have confirmed the hypothesis and more than one theory has been developed to explain the phenomenon. Since the two glands both have secretory functions and are regulated by the hypothalamic-pituitary axis, they may share some common oncogenic molecular pathways. However, other risks factors, including medical interventions and hormones, are also observed to play a role. This article aims to provide a comprehensive review of the associations between the two cancers. The putative mechanisms, such as hormone alteration, autoimmune attack, genetic predisposition and other life-related factors are reviewed and discussed. Medical interventions, such as chemotherapy and radiotherapy, can also increase the risk of second primary cancers. This review will provide novel insights into the research designs, clinical managements and treatments of thyroid and breast cancer patients.

Thyroid cancer in children: A multicenter international study highlighting clinical features and surgical outcomes of primary and secondary tumors

BACKGROUND

Thyroid gland malignancies are rare in pediatric patients (0.7% of tumors); only 1.8% are observed in patients aged <20 years, with a higher prevalence recorded in women and adolescents. Risk factors include genetic syndromes, MEN disorders, autoimmune diseases, and exposure to ionizing radiation. Radiotherapy is also associated with an increased risk of secondary thyroid cancer. This study describes the clinical features and surgical outcomes of primary and secondary thyroid tumors in pediatric patients.

METHODS

Institutional data were collected from eight international surgical oncology centers for pediatric patients with thyroid cancer between 2000 and 2020. Statistical analyses were performed using the GraphPad Prism software.

RESULTS

Among 255 total cases of thyroid cancer, only 13 (5.1%) were secondary tumors. Primary thyroid malignancies were more likely to be multifocal in origin (odds ratio [OR] 1.993, 95% confidence interval [CI].7466-5.132, p = 0.2323), have bilateral glandular location (OR 2.847, 95% CI.6835-12.68, p = 0.2648), and be metastatic at first diagnosis (OR 1.259, 95% CI.3267-5.696, p > 0.999). Secondary tumors showed a higher incidence of disease relapse (OR 1.556, 95% CI.4579-5.57, p = 0.4525) and surgical complications (OR 2.042, 95% CI 0.7917-5.221, p = 0.1614), including hypoparathyroidism and recurrent laryngeal nerve injury. The overall survival (OS) was 99% at 1 year and 97% after 10 years. No EFS differences were evident between the primary and secondary tumors (chi-square 0.7307, p = 0.39026).

CONCLUSIONS

This multicenter study demonstrated excellent survival in pediatric thyroid malignancies. Secondary tumors exhibited greater disease relapse (15.8 vs. 10.5%) and a higher incidence of surgical complications (36.8 vs. 22.2%).

Genetic Landscape of Papillary Thyroid Carcinoma and Nuclear Architecture: An Overview Comparing Pediatric and Adult Populations

Thyroid cancer is a rare malignancy in the pediatric population that is highly associated with disease aggressiveness and advanced disease stages when compared to adult population. The biological and molecular features underlying pediatric and adult thyroid cancer pathogenesis could be responsible for differences in the clinical presentation and prognosis. Despite this, the clinical assessment and treatments used in pediatric thyroid cancer are the same as those implemented for adults and specific personalized target treatments are not used in clinical practice. In this review, we focus on papillary thyroid carcinoma (PTC), which represents 80-90% of all differentiated thyroid carcinomas. PTC has a high rate of gene fusions and mutations, which can influence the histologic subtypes in both children and adults. This review also highlights telomere-related genomic instability and changes in nuclear organization as novel biomarkers for thyroid cancers.

Long-term results of suppressing thyroid-stimulating hormone during radiotherapy to prevent primary hypothyroidism in medulloblastoma/PNET and Hodgkin lymphoma: a prospective cohort study

Primary hypothyroidism commonly occurs after radiotherapy (RT), and coincides with increased circulating thyroid-stimulating hormone (TSH) levels.We tested therefore the protective effect of suppressing TSH with L-thyroxine during RT for medulloblastoma/PNET and Hodgkin lymphoma (HL) in a prospective cohort study. From1998 to 2001, a total of 37 euthyroid children with medulloblastoma/PNET plus 14 with HL, scheduled for craniospinal irradiation and mediastinum/neck radiotherapy, respectively, underwent thyroid ultrasound and free triiodothyronine (FT3), free thyroxine (FT4), and TSH evaluation at the beginning and end of craniospinal iiradiation. From 14 days before and up to the end of radiotherapy, patients were administered L-thyroxine checking every 3 days TSH to ensure a value < 0.3 μIU/mL. During follow-up, blood tests and ultrasound were repeated; primary hypothyroidism was considered an increased TSH level greater than normal range. Twenty-two/37 patients with medulloblastoma/PNET and all the 14 patients with HL were alive after a median 231 months from radiotherapy with 7/22 and 8/14 having correctly reached TSH levels < 0.3 μIU/mL and well matched for other variables. Twenty years on, hypothyroidism-free survival rates differed significantly, being 60% ± 15% and 15.6% ± 8.2% in TSH-suppressed vs. not-TSH suppressed patients, respectively (P = 0.001). These findings suggest that hypothyroidism could be durably prevented in two populations at risk of late RT sequelae, but it should be confirmed in a larger cohort.

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.

Second primary cancers in people who had cancer as children: an Australian Childhood Cancer Registry population-based study

OBJECTIVE

To investigate the incidence of second primary cancers in people diagnosed with cancer during childhood.

DESIGN, SETTING

Retrospective, population-based study; analysis of Australian Childhood Cancer Registry data.

PARTICIPANTS

People alive at least two months after being diagnosed before the age of 15 years with a primary cancer, 1983-2013, followed until 31 December 2015 (2-33 years' follow-up).

MAIN OUTCOME MEASURES

Risks of second primary cancer compared with the general population, expressed as standardised incidence ratios (SIRs).

RESULTS

Among 18 230 people diagnosed with cancer during childhood, 388 (2%) were later diagnosed with second primary cancers; the estimated 30-year cumulative incidence of second cancers was 4.4% (95% CI, 3.8-5.0%). The risk of a new primary cancer was five times as high as for the general population (SIR, 5.13; 95% CI, 4.65-5.67). Relative risk of a second primary cancer was greatest for people who had childhood rhabdomyosarcoma (SIR, 19.9; 95% CI, 14.4-27.6). Relative risk was particularly high for children who had undergone both chemotherapy and radiotherapy (SIR, 9.80; 95% CI, 8.35-11.5). Relative risk peaked during the 5 years following the first diagnosis (2 to less than 5 years: SIR, 10.3; 95% CI, 8.20-13.0), but was still significant at 20-33 years (SIR, 2.58; 95% CI, 2.02-3.30). The most frequent second primary cancers were thyroid carcinomas (65 of 388, 17%) and acute myeloid leukaemias (57, 15%).

CONCLUSIONS

Survivors of childhood cancer remain at increased risk of a second primary cancer well into adulthood. As the late effects of cancer treatment probably contribute to this risk, treatments need to be refined and their toxicity reduced, without reducing their benefit for survival.

Normal tissue damage: its importance, history and challenges for the future

Sir Oliver Scott, a philanthropist and radiation biologist and, therefore, the epitome of a gentleman and a scholar, was an early Director of the BECC Radiobiology Research Unit at Mount Vernon. His tenure preceded that of Jack Fowler, with both contributing to basic, translational and clinical thought and application in radiation across the globe. With respect to this review, Fowler's name in particular has remained synonymous with the use of models, both animal and mathematical, that assess and quantify the biological mechanisms that underlie radiation-associated normal tissue toxicities. An understanding of these effects is critical to the optimal use of radiation therapy in the clinic; however, the role that basic sciences play in clinical practice has been undergoing considerable change in recent years, particularly in the USA, where there has been a growing emphasis on engineering and imaging to improve radiation delivery, with empirical observations of clinical outcome taking the place of models underpinned by evidence from basic science experiments. In honour of Scott and Fowler's work, we have taken this opportunity to review how our respective fields of radiation biology and radiation physics have intertwined over the years, affecting the clinical use of radiation with respect to normal tissue outcomes. We discuss the past and current achievements, with the hope of encouraging a revived interest in physics and biology as they relate to radiation oncology practice, since, like Scott and Fowler, we share the goal of improving the future outlook for cancer patients.

Radiation-associated breast cancer and gonadal hormone exposure: a report from the Childhood Cancer Survivor Study

BACKGROUND

The relationship between hormone exposure and breast cancer risk in women treated with chest radiotherapy for childhood cancer is uncertain.

METHODS

Participants included 1108 females from the Childhood Cancer Survivor Study who were diagnosed with childhood cancer 1970-1986, treated with chest radiotherapy, and survived to ages ⩾20 years. Hazard ratios (HRs) and 95% confidence intervals (CIs) from Cox models adjusted for chest radiation field, delivered dose, anthracycline exposure, and age at childhood cancer estimated risk.

RESULTS

Among 195 women diagnosed with breast cancer, 102 tumours were oestrogen-receptor positive (ER+). Breast cancer risk increased with ⩾10 years of ovarian function after chest radiotherapy vs <10 years (HR=2.89, CI 1.56-5.53) and for radiotherapy given within 1 year of menarche vs >1 year from menarche (HR=1.80, CI 1.19-2.72). Risk decreased with decreasing age at menopause (P_trend=0.014). Risk factors did not differ for ER+ breast cancer. Survivors with an age at menopause <20 years treated with hormone therapy had a lower breast cancer risk than premenopausal survivors (HR=0.47, CI 0.23-0.94).

CONCLUSIONS

Endogenous hormones are key contributors to breast cancer observed among childhood cancer survivors. Hormone therapy given for premature ovarian insufficiency does not fully replace the function that endogenous hormones have in breast cancer development.

Radiation-associated neoplasia: clinical, pathological and genomic correlates

Ionizing radiation is an established risk factor for the development of benign and malignant tumours. The epidemiology of radiation-associated neoplasia has been studied over the decades in diverse populations, including Japanese atomic bomb survivors, exposed communities following the Chernobyl nuclear power plant disaster, and paediatric and adult populations receiving therapeutic irradiation. Radiation has been associated with an increased risk of neoplasia throughout the human body, with some sites showing a markedly increased relative risk of developing tumours (thyroid; soft tissues), depending on patient age and the context of exposure. Although the mechanisms of cellular injury and repair resulting from ionizing radiation are well described, the genomics of radiation-induced tumours are still relatively poorly understood, with some exceptions, such as RET rearrangement in thyroid carcinomas following iodine-131 exposure and MYC amplification in cutaneous angiosarcoma following chest wall irradiation for breast cancer. This review will provide a general overview of the epidemiology, molecular mechanism, pathology and genomics of radiation-associated neoplasia in humans.