Thyroid function in children after cytostatic treatment for acute leukemia

Late thyroid complications in survivors of childhood acute leukemia. An L.E.A. study

Thyroid complications are known side effects of irradiation. However, the risk of such complications in childhood acute leukemia survivors who received either central nervous system irradiation or hematopoietic stem cell transplantation is less described. We prospectively evaluated the incidence and risk factors for thyroid dysfunction and tumors in survivors of childhood acute myeloid or lymphoid leukemia. A total of 588 patients were evaluated for thyroid function, and 502 individuals were assessed for thyroid tumors (median follow-up duration: 12.6 and 12.5 years, respectively). The cumulative incidence of hypothyroidism was 17.3% (95% CI: 14.1-21.1) and 24.6% (95% CI: 20.4-29.6) at 10 and 20 years from leukemia diagnosis, respectively. Patients who received total body irradiation (with or without prior central nervous system irradiation) were at higher risk of hypothyroidism (adjusted HR: 2.87; P=0.04 and 2.79, P=0.01, respectively) as compared with transplanted patients who never received any irradiation. Patients transplanted without total body irradiation who received central nervous system irradiation were also at higher risk (adjusted HR: 3.39; P=0.02). Patients irradiated or transplanted at older than 10 years of age had a lower risk (adjusted HR: 0.61; P=0.02). Thyroid malignancy was found in 26 patients (5.2%). Among them, two patients had never received any type of irradiation: alkylating agents could also promote thyroid cancer. The cumulative incidence of thyroid malignancy was 9.6% (95% CI: 6.0-15.0) at 20 years. Women were at higher risk than men (adjusted HR: 4.74; P=0.002). In conclusion, thyroid complications are frequent among patients who undergo transplantation after total body irradiation and those who received prior central nervous system irradiation. Close monitoring is thus warranted for these patients. Clinicaltrials.gov identifier: NCT 01756599.

Thyroid abnormalities in survivors of childhood cancer

OBJECTIVE

To investigate the late side effects of childhood cancer therapy on the thyroid gland and to determine the risk factors for development of thyroid disorder among childhood cancer survivors.

METHODS

One hundred and twenty relapse-free survivors of childhood cancer (aged 6-30 years) were included in this study. The diagnoses of patients were lymphoma, leukemia, brain tumor, rhabdomyosarcoma and nasopharyngeal carcinoma (NPC). The patients were divided into two groups depending on the treatment: group 1-chemotherapy (ChT) only (n=52) and group 2-combination therapy of ChT + radiotherapy (RT) (head/neck/thorax) (n=68). Thyroid function tests, urinary iodine levels, and thyroid gland ultrasound examinations were evaluated in both groups.

RESULTS

Incidence of thyroid disease was 66% (n=79) in the survivors. The thyroid abnormalities were: hypothyroidism (HT) (n=32, 27%), thyroid nodules (n=27, 22%), thyroid parenchymal heterogeneity (n=40, 33%), autoimmune thyroiditis (n=36, 30%), and thyroid malignancy (n=3, 2%). While the incidence of HT and thyroid nodules in group 2 was significantly higher than in group 1, the incidence of thyroid parenchymal heterogeneity and autoimmune thyroiditis was similar in the two patient groups. HT and thyroid malignancy were seen only in group 2. In multivariate logistic regression analysis, a history of Hodgkin lymphoma (HL), brain tumor and NPC, as well as cervical irradiation and 5000-5999 cGy doses of radiation were found to constitute risk factors for HT. History of HL and 4000-5999 cGy doses of radiation were risk factors for thyroid nodules. Head/neck irradiation and treatment with platinum derivatives were risk factors for autoimmune thyroiditis. In univariate analysis, a history of NPC, cervical + nasopharyngeal irradiation, and treatment with platinum derivatives were risk factors for thyroid parenchymal heterogeneity.

CONCLUSION

Our results indicate that there is especially an increased risk of HT and thyroid nodules in patients treated with combination therapy of ChT with head/neck/thorax RT. Although chemotherapeutic agents per se do not seem to cause HT, longer follow-up is needed to assess whether or not there is an increased risk for autoimmune thyroiditis and thyroid parenchymal heterogeneity after antineoplastic therapy.

Central hypothyroidism following chemotherapy for acute lymphoblastic leukemia

BACKGROUND

It has been suggested that chemotherapy per se might impair the hypothalamus-pituitary-thyroid axis of childhood cancer survivors.

OBJECTIVE

We examined six patients treated for acute lymphoblastic leukemia (ALL) with chemotherapy alone, with suspicious central hypothyroidism (CH).

SUBJECTS AND METHODS

ALL was diagnosed at a mean age of 3.8 years (range 0.3-6 years), the mean follow-up is 6 years (range 6-13 years). Auxological data were recorded, and thyroid function, autoimmunity and ultrasonography (US) were evaluated. Three individuals underwent a thyrotropin-releasing hormone (TRH) test and a magnetic resonance imaging (MRI) scan of the hypothalamic-pituitary region.

RESULTS

All study participants showed negative thyroid autoimmunity, normal thyroid ultrasound, and thyroid-stimulating hormone (TSH) above the normal range; free T4 (fT4) was abnormally low in two patients. After TRH infusion all patients showed TSH increase and slow TSH decline.

CONCLUSIONS

Our study shows that CH could arise at any time after childhood leukemia following only chemotherapy treatment. Although overt hypothyroidism was detected in only two patients, a careful follow-up of thyroid function is also recommended for ALL survivors not treated by irradiation.

Assessment of bone mineral density and risk factors in children completing treatment for acute lymphoblastic leukemia

BACKGROUND

Reduced bone mineral density and increased fracture risk have been reported in children with cancer. In this study, we aimed to determine the growth and bone mineral density (BMD) of the children off chemotherapy for acute lymphoblastic leukemia, and the probable risk factors.

PROCEDURE

The age, anthropometric measurements, lumbar spine BMDs were recorded in 70 children. The risk factors on BMD; daily calcium intake, the time interval from the completion of the chemotherapy, cranial radiotherapy, cumulative steroid dose, decrease in physical activity were investigated. Serum calcium, phosphate, alkaline phosphates, magnesium, insulin-like growth factor-1 (IGF-1) and 25 (OH) vitamin D levels were determined.

RESULTS

The mean height percentile at the time of diagnosis was decreased from the value of 53 to a value of 47 at the beginning of the study (P=0.071). Of them; 44% had osteoporosis, 41% had osteopenia, and the rest had normal BMD. BMD z-scores were decreased during the first 2 years from the completion of the treatment. There was a positive correlation between BMD z-scores and daily calcium intake (CC=0.366, P=0.0015). A negative correlation was determined between the time spent on TV and computers and BMD z-scores (CC=-0.464, P=0.0019). Serum IGF-1 and 25 (OH) vitamin D levels of patients were significantly lower than controls (P=0.033).

CONCLUSIONS

Our data revealed that 85% of the survivors had bone mineralization defect. BMDs and z scores were decreased during the first 2 years from the completion of the treatment and then gradually began to increase. The most important risk factor for decreased BMD was low daily calcium intake. Therefore, patients and their families should be encouraged to take sufficient amount of calcium. Prophylactic vitamin D may also be supplemented.

Thyroid function and thyroid autoimmunity in childhood acute lymphoblastic leukemia off-therapy patients treated only with chemotherapy

OBJECTIVE

Scanty data are available about the thyroid function in childhood acute lymphoblastic leukemia (ALL) off-therapy patients treated only with chemotherapy. We aimed to assess the prevalence of thyroid autoimmunity and thyroid dysfunction in such patients.

DESIGN

Case-control cross-sectional study.

METHODS

Eighty-four patients diagnosed with ALL and treated only with chemotherapy. Mean age at diagnosis 5.9+/-3.6 yr, at recruitment 12.1+/-4.3 yr. The treatment had been stopped 4.3+/-3.2 yr before recruitment. A control group of 60 subjects was recruited. Free T4, TSH, anti-thyroperoxidase, and anti-thyroglobulin antibodies were measured.

RESULTS

Anti-thyroglobulin and anti-thyroperoxidase antibodies were negative in all patients. TSH was increased in 7 patients (8.3%) and 3 controls (5.0%). Free T4 was within the normal limits in all patients and controls.Mean TSH and free T4 levels did not statistically differ between controls and ALL offtherapy patients. TSH was negatively correlated with the age at the diagnosis (p=0.01) and the age at the end of therapy (p=0.008). Anti-thyroglobulin and/or anti-thyroperoxidase antibodies were detected in 3 controls (5%; vs study group: p=0.038), 1 of them with increased TSH.

CONCLUSIONS

Some patients present hyperthyrotropinemia, without anti-thyroid antibodies, with a prevalence comparable to the control group. The thyroid gland seems more prone to be damaged by chemotherapy at a younger age. We think that a thyroid follow- up in ALL off-therapy patients may be advisable and should be differentiated on the basis of the age at the end of treatment, with more frequent tests for younger patients.

Risk of thyroid dysfunction and subsequent thyroid cancer among survivors of acute lymphoblastic leukemia: a report from the Childhood Cancer Survivor Study

BACKGROUND

To determine the risk of thyroid dysfunction and subsequent thyroid cancer among childhood acute lymphoblastic leukemia (ALL) survivors.

PROCEDURE

Rates of self-reported thyroid dysfunction and thyroid cancer were determined among 3,579 ALL survivors participating in the Childhood Cancer Survivor Study, a cohort of 5-year survivors of pediatric cancers diagnosed from 1970 to 1986, and compared with 3,846 siblings and population rates, respectively.

RESULTS

The cumulative incidence of hypo- and hyperthyroidism among survivors 15 years following leukemia diagnosis was 1.6% (95% CI 1.1, 2.1) and 0.6% (95% CI 0.3, 1.1), respectively, both significantly increased compared with siblings. In multivariate analysis, survivors who received >or=20 Gy cranial radiotherapy plus any spinal radiotherapy had the highest risk of subsequent hypothyroidism (HR 8.3, 95% CI 3.3, 20.5) compared with those treated with chemotherapy alone. Craniospinal radiotherapy also was associated with an increased risk of subsequent hyperthyroidism (HR 6.1, 95% CI 1.1, 34.2) compared with chemotherapy alone, as well as an increased risk of subsequent thyroid cancers (SIR 30.3, 95% CI 14.5, 55.7) compared with population rates. In radiation dosimetry analysis, pituitary doses >or=20 Gy combined with thyroid doses >or=10 Gy were associated with hypothyroidism, whereas pituitary doses >or=20 Gy combined with thyroid doses >or=15 Gy were associated with hyperthyroidism.

CONCLUSIONS

The risk of thyroid dysfunction and thyroid cancer was increased among childhood ALL survivors treated with craniospinal radiotherapy. In these individuals, long-term surveillance is warranted as no obvious plateau in risk was seen, even after 25 years of follow-up.

The natural history of thyroid function abnormalities after treatment for childhood cancer

The aim of the study was to find out which of childhood cancer survivors are at higher risk of thyroid dysfunction, and the timeframe for its development. The consequences of different treatments, particularly chemotherapy, were of interest. Follow-up data for 291 patients from a cohort of 360 patients were available and analysed in this retrospective study. Impaired thyroid function occurred in 71/291 (24%) patients: brain tumours 30/65 (46%), Hodgkin's disease (HD) 10/21 (48%), leukaemia/non Hodgkin's lymphoma (NHL) 19/140 (14%) and others 12/65 (18%). Patients with brain tumours had a higher hazard ratio (HR) over leukaemia/NHL (HR 7.47) but not over HD (HR 1.57). These patients also developed thyroid hypofunction earlier than patients with HD or leukaemia/NHL. Age at diagnosis did not have an effect on the occurrence or timeframe of development of thyroid hypofunction. Radiotherapy (HR 4.68) and radiotherapy combined with chemotherapy (HR 2.90) were associated with a higher risk than chemotherapy alone. Chemotherapy added to radiotherapy tended to increase risk (HR 2.42 95% confidence interval (CI) 1.00-5.87). Craniospinal irradiation did not differ significantly from total body irradiation (TBI) (HR 1.09 95%CI 0.25-4.76) or direct thyroid irradiation (HR 0.81 95%CI 0.32-2.06), but cranial irradiation (CIR) (HR 0.18 95%CI 0.08-0.38) was less harmful to thyroid function. Girls were more prone to effects of irradiation (HR 2.10 95%CI 1.15-3.82). All treatments, excluding surgery, predispose to thyroid dysfunction. Suggestions for follow-up of thyroid function are made.

Thyrotoxic crisis induced by cytotoxic chemotherapy

Thyroid storm is a rare and life-threatening medical emergency. We report a young lady with Graves' disease and acute myeloid leukaemia who developed thyrotoxic crisis following an induction course of chemotherapy given for the treatment of acute leukaemia. After successful management of her leukaemia and thyroid disease, she received an autologous bone marrow transplantation.

Thyroid carcinoma presenting in childhood or after treatment of childhood malignancies: An institutional experience and review of the literature

BACKGROUND/PURPOSE

Thyroid carcinomas can occur as a primary malignancy (PTM) or secondary after another malignancy (STM). Information about the presentations and outcomes of patients with STM are limited. The authors sought to compare the clinical characteristics, course, and outcomes of patients with primary or secondary thyroid malignancies.

METHODS

The authors reviewed the medical records of 8 children with PTM and 17 children with STM referred to St Jude Children's Research Hospital between February 1962 and February 2002 for evaluation and treatment of malignant thyroid carcinoma.

RESULTS

The 8 children who had primary thyroid carcinoma had it diagnosed at a median age of 12.5 years (range, 7.3 to 16.3 years). Seven patients had papillary carcinoma, and 1 patient had follicular carcinoma. Three of the 8 (37.5%) had metastatic disease involving regional lymph nodes; 2 patients (25.0%) had lung metastases. Six patients required radioactive iodine (I 131) ablation for residual or metastatic disease after surgical resection. All 8 patients remain alive a median of 22.6 years after diagnosis (range, 0.7 to 30.5 years); 1 continues to receive radioactive iodine (I 131) ablation for persistent disease. Seventeen patients had thyroid carcinoma as a second malignant neoplasm after treatment for acute lymphoblastic leukemia (n = 6), Hodgkin's disease (n = 5), central nervous system tumor (n = 2), Wilms' tumor (n = 1), retinoblastoma (n = 1), non-Hodgkin's lymphoma (n = 1), or neuroblastoma (n = 1). Patients with secondary thyroid carcinoma presented at a median age of 21.5 years (range, 15.3 to 42.6 years), a median of 16.2 years (range, 0.9 to 29.2 years) after diagnosis of the primary cancer. Twelve of the 17 patients (70.6%) had received radiation to the thyroid gland during therapy for the primary cancer. Four patients (23.5%) had metastatic disease involving regional lymph nodes. Six patients (35.3%) required I(131) ablation for residual or metastatic disease after thyroidectomy. At the time of this report, all 17 patients are alive and in continue to be free of disease.

CONCLUSIONS

Pediatric thyroid carcinoma is uncommon and responds well to current therapy. Given the limited period of follow-up of our cohort of secondary malignant thyroid tumors that arise after childhood cancer, these lesions appear to have similar presentations and outcomes when compared with primary carcinomas and can therefore be managed in the same manner.

Endocrine complications in pediatric patients with acute lymphoblastic leukemia

Endocrine complications of therapy for acute lymphoblastic leukemia (ALL) are common and are potentially debilitating both during and after therapy. Growth velocity slows during therapy for ALL, especially during the first year; however, children who do not receive cranial irradiation usually reach normal adult height. While growth hormone deficiency generally occurs in patients who have received 24Gy of cranial irradiation, it may also develop in those treated with lower doses (18Gy) of cranial radiation or with only high-dose methotrexate. Obesity commonly occurs during therapy and persists after completion of therapy. Osteopenia can occur early during therapy for ALL and can persist for many years. Adrenal insufficiency should be suspected in any child who has recently received glucocorticoid therapy, and stress doses of steroid should be administered in the event of metabolic stress. Screening of urine is useful for early detection of hyperglycemia during therapy with glucocorticoids and L-asparaginase. The syndrome of inappropriate secretion of anti-diuretic hormone is usually associated with vincristine therapy and may be aggravated by concurrent use of azole antifungals. Finally, patients who have received 18 or 24Gy of cranial irradiation may have clinical or subclinical deficiencies of thyroid hormones.