131I therapy for differentiated thyroid cancer leads to an earlier onset of menopause: results of a retrospective study

Premature ovarian insufficiency in female adolescent and young adult survivors of non-gynecological cancers: a population-based cohort study

BACKGROUND

The risk of premature ovarian insufficiency (POI) is increased in adolescent and young adult (AYA) cancer survivors, with the prevalence depending on cancer diagnosis, treatment, and patient factors. Prior studies are limited by sample size and type of cancer included. The objective of this study was to assess the risk of POI in female AYA survivors of non-gynecologic cancers, using a population-based approach.

METHODS

This population-based retrospective cohort study comprises 21,666 females, 15-39 years old, diagnosed with a single non-gynecologic cancer in Ontario, Canada from 1995 to 2015. Through health administrative data linkage, participants were followed until their 40th birthday, December 31, 2018, bilateral oophorectomy, loss of health insurance eligibility or death. Each cancer survivor was matched to 5 females who were not diagnosed with cancer (unexposed, n = 108,330). Women with bilateral oophorectomy or a prior menopause diagnosis were excluded. POI was identified through use of the ICD-9 code for menopause (ICD9-627). Modified Poisson regression models were used to calculate the adjusted relative risk (aRR) of POI for AYA cancer survivors compared to unexposed individuals, adjusted for income, parity, age, and immigration status.

RESULTS

The occurrence of POI was higher in survivors of AYA cancer versus unexposed patients (5.4% vs. 2.2%). Survivors of AYA cancer had an increased risk of POI relative to unexposed patients (aRR 2.49; 95% CI 2.32-2.67). Risk varied by type of cancer: breast (4.32; 3.84-4.86), non-Hodgkin's lymphoma (3.77; 2.88-4.94), Hodgkin's lymphoma (2.37; 1.91-2.96), leukemia (14.64; 10.50-20.42), thyroid (1.26; 1.09-1.46) and melanoma (1.04; 0.82-1.32). Risk varied by age at time of cancer diagnosis, with a higher risk among females diagnosed at age 30-39 years (3.07; 2.80-3.35) than aged 15-29 years (1.75; 1.55-1.98).

CONCLUSIONS

AYA survivors of non-gynecologic cancers are at an increased risk of POI, particularly survivors of lymphomas, leukemia, breast, and thyroid cancer. The risk of POI is increased for those diagnosed with cancer at an older age. These results should inform reproductive counseling of female AYAs diagnosed with cancer.

Radioactive iodine and female fertility

Radioactive iodine (I131) is used after surgery in the treatment of Differentiated Thyroid Carcinoma (DTC). There is no solid evidence about the potential deleterious effect of I131 on women fertility. The objective of this study is to assess the impact that I131 may have on fertility in women. All women followed by DTC in our department have been analyzed and women younger than 45 years old at the time of diagnosis and initial treatment were included. There were 40 women exposed to I131 (study group) and 11 women who were only treated with thyroidectomy (control group). Of the women exposed to I131, 40% went through early menopause, while no cases were reported among their controls. Furthermore, 29.2% of women exposed to I131 had decreased Antimüllerian Hormone (AMH), compared to the only 11% of unexposed women (not significant). Regarding the fertility impairment "perceived" by patients, in the group of women exposed to iodine, 17.9% described being unable to complete their genesic desire whereas, none was registered in the control group. We conclude that radioactive iodine can affect a woman's fertility and shorten her reproductive life, so this is an aspect that should be taken into consideration.

Pregnancy Outcomes in Thyroid Cancer Survivors: A Propensity Score-Matched Cohort Study

BACKGROUND

Some female thyroid cancer survivors wish to become pregnant following their cancer treatment. Current studies have shown inconsistent results on pregnancy outcomes in these survivors; however, detailed information on the pathological type, treatment, and gestational thyroid function of these patients are not yet well documented, making the refined assessment of the influence of a history of thyroid cancer and related treatments on pregnancy outcomes challenging.

OBJECTIVE

To investigate the risk of adverse pregnancy outcomes in thyroid cancer survivors.

METHODS

This was a retrospective cohort study. We included all women aged between 19 and 45 years old who delivered between January 2019 and June 2020 in West China Second University Hospital of Sichuan University. Women with tumors other than thyroid cancer or other thyroid diseases were excluded. The included women were divided into survivors of thyroid cancer (survivors) and women without any history of thyroid disease (controls). Propensity score matching and logistic regression were used to control confounding variables.

RESULTS

All 18,332 women who met the inclusion criteria were included in the study (96 survivors of papillary thyroid cancer and 18,236 controls). After propensity score matching, 96 survivors and 192 controls were included. The survivors had higher levels of free thyroxine (15.47 [13.61-17.67] vs. 14.38 [13.20-15.81] pmol/mL; P<0.001) and higher levels of thyroid peroxidase antibodies (TPOAb) (43.55 [31.43-71.43] vs. 35.95 [28.00-48.03] U/mL; P=0.008) but similar levels of thyroid stimulating hormone (1.46 [0.56-3.15] vs. 1.36 [0.81-1.92] mIU/mL; P=0.142) than the controls. There were no significant differences in adverse pregnancy outcomes between survivors and controls. Fetal macrosomia was lower among survivors (OR: 0.077, 95% CI: 0.009-0.668. P=0.020) than controls. Additionally, survivors had reduced weight gain during pregnancy (13.0 [10.0-15.0] vs. 14.00 [11.00-16.00] kg, P=0.005) and reduced placental weight (563.0 [514.5-620.0] vs. 572.0 [520.0-650.0] g, P=0.019), albeit with small absolute differences. Thyroidectomy or radioiodine therapy did not adversely affect pregnancy outcomes.

CONCLUSION

A history of treated papillary thyroid cancer was not associated with adverse pregnancy outcomes.

Impact of thyroid cancer treatment on assisted reproductive technology outcomes in women with infertility

Purpose

We investigated the effect of different surgical procedures and radioactive iodine treatment (RAIT) on in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes and evaluated whether possible risk factors, including age, thyroid-stimulating hormone (TSH) levels, and thyroid antibody positivity, were associated with adverse IVF/ICSI outcomes.

Methods

This retrospective study included 76 women with infertility who had received thyroid cancer (TC) treatment among 137,698 infertile women who underwent IVF/ICSI cycles at the Peking University Third Hospital between 2010 and 2019. Clinical pregnancy and live birth rates were assessed.

Results

We found that the clinical pregnancy and live birth rates in women who underwent partial thyroidectomy were 7- and 6-fold higher, respectively, than those in women who underwent total thyroidectomy. We observed no significant differences in the clinical pregnancy and live birth rates between the RAIT and non-RAIT groups, even after adjusting for age, TSH levels, surgical treatment, and thyroid antibody positivity. Multivariate logistic regression analysis showed that age and TSH levels were not associated with decreased clinical pregnancy and live birth rates. Women with thyroid antibody positivity had significantly lower clinical pregnancy and live birth rates than women without thyroid antibody positivity.

Conclusion

Our study showed lower clinical pregnancy and live birth rates in women who underwent total thyroidectomy than in women who underwent partial thyroidectomy. Thyroid antibody positivity is an important risk factor for adverse IVF/ICSI outcomes in women who have received TC treatment.

The Effect of Radioactive Iodine Therapy on Ovarian Function and Fertility in Female Thyroid Cancer Patients: A Systematic Review and Meta-Analysis

Introduction: Thyroid cancer is one of the most common carcinomas diagnosed in adolescents and young adults, with a rapidly rising incidence for the past three decades. Surgery is the standard treatment for patients with differentiated thyroid carcinoma (DTC), and when indicated, followed by radioactive iodine (RAI) treatment. The aim of this study was to evaluate the possible effects of RAI therapy on ovarian function and fertility in women. Methods: The PubMed, Embase, and Web of Science databases were systematically searched up to January 2020. In addition, a meta-analyses were performed for anti-Mullerian hormone (AMH) levels after RAI, comparison of AMH levels prior and 1 year after RAI, and pregnancy rates in patient with thyroid cancer receiving RAI compared with patients with thyroid cancer who did not receive RAI. Results: A total of 36 studies were eligible for full-text screening and 22 studies were included. The majority of the studies had a retrospective design. Menstrual irregularities were present in the first year after RAI in 12% and up to 31% of the patients. Approximately 8-16% of the patients experienced amenorrhea in the first year after RAI. Women who received RAI treatment (median dose 3700 MBq [range 1110-40,700 MBq]); had menopause at a slightly younger age compared with women who did not receive RAI treatment, 49.5 and 51 years, respectively (p < 0.001). Pooled AMH of the seven studies reporting AMH concentrations after RAI was 1.79 ng/mL. Of these, four studies reported AMH concentrations prior and 1 year after RAI. The mean difference was 1.50 ng/mL, which was significant. Finally, meta-analysis showed that patients undergoing RAI were not at a decreased risk of becoming pregnant. Conclusions: Most of the studies indicate that RAI therapy for DTC is not associated with a long-term decrease in pregnancy rates although meta-analyses show a significant decrease in AMH levels after RAI therapy. Prospective studies are needed to confirm these results. We recommend counseling patients about the possible effects of ¹³¹I and incorporate today's knowledge in multidisciplinary counseling.

The revised clinical practice guidelines on the management of thyroid tumors by the Japan Associations of Endocrine Surgeons: Core questions and recommendations for treatments of thyroid cancer

The Japan Associations of Endocrine Surgeons has developed the revised version of the Clinical Practice Guidelines for Thyroid Tumors. This article describes the guidelines translated into English for the 35 clinical questions relevant to the therapeutic management of thyroid cancers. The objective of the guidelines is to improve health-related outcomes in patients with thyroid tumors by enabling users to make their practice evidence-based and by minimizing any variations in clinical practice due to gaps in evidential knowledge among physicians. The guidelines give representative flow-charts on the management of papillary, follicular, medullary, and anaplastic thyroid carcinoma, along with recommendations for clinical questions by presenting evidence on the relevant outcomes including benefits, risks, and health conditions from patients' perspective. Therapeutic actions were recommended or not recommended either strongly (◎◎◎ or XXX) based on good evidence (😊)/good expert consensus (+++), or weakly (◎, ◎◎ or X, XX) based on poor evidence (😣)/poor expert consensus (+ or ++). Only 10 of the 51 recommendations given in the guidelines were supported by good evidence, whereas 35 were supported by good expert consensus. While implementing the current guidelines would be of help to achieve the objective, we need further clinical research to make our shared decision making to be more evidence-based.

Cross-sectional and prospective study on anti-Müllerian hormone changes in a cohort of pre-menopausal women with a history of differentiated thyroid cancer

Background

Anti-Müllerian hormone (AMH) decreases acutely after post-surgical radioactive iodine (RAI) ablation in females with differentiated thyroid cancer (DTC).

Aim

We performed a cross-sectional and prospective study on AMH levels in pre-menopausal females with a history of DTC.

Methods

Fifty-nine females after surgery and RAI (group 1) and 30 females after surgery alone (group 2) were studied. The control group consisted of 141 healthy women (group 3). The prospective study was performed in 43 and 14 females from groups 1 and 2, respectively.

Results

On first evaluation, AMH levels were similar in groups 1 and 2, but lower than in group 3. In all groups, AMH was negatively related with chronological age and FSH levels. When subjects were stratified according to age, AMH levels were not different between groups. When AMH was evaluated up to 2 years after the baseline evaluation, no changes emerged in either group of women with DTC. In the prospective study, the incidence of abnormal menstrual cycles and the onset of menopause were observed in similar percentages of women with a history of RAI-treated DTC and of those treated with surgery alone.

Conclusions

AMH can be considered a reliable index of ovarian reserve in women with DTC. Chronological age is the main factor influencing AMH levels in both DTC patients and controls. After age-related stratification, AMH levels are similar in women with DTC treated with RAI and those treated with surgery alone.

Cancer Treatment-Related Infertility: A Critical Review of the Evidence

Cancer treatments may compromise the fertility of children, adolescents, and young adults, and treatment-related infertility represents an important survivorship issue that should be addressed at diagnosis and in follow-up to ensure optimal decision-making, including consideration of pursuing fertility preservation. Risk of infertility varies substantially with patient and treatment factors. The ability to accurately assess fertility risk for many patients is hampered by limitations of the current literature, including heterogeneity in patient populations, treatments, and outcome measures. In this article, we review and synthesize the available data to estimate fertility risks from modern cancer treatments for both children and adult cancer survivors to enable clinicians to counsel patients about future fertility.

Effects of Radioactive Iodine Therapy on Ovarian Reserve: A Prospective Pilot Study

Background: Thyroid carcinoma is the most common endocrine malignancy. Surgery is the standard therapeutic approach for patients with differentiated thyroid carcinoma (DTC), followed by radioiodine (RAI) therapy if indicated. For women with DTC, the effects of RAI therapy on gonadal and reproductive function are an important consideration. This study aimed to evaluate the effects of RAI therapy on ovarian function. Methods: A total of 33 premenopausal women were enrolled in this study. Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, and anti-Müllerian hormone (AMH) levels during the early follicular phase were measured before and 3, 6, and 12 months after RAI therapy. The Friedman and Wilcoxon tests were used to detect changes in FSH, AMH, LH, and estradiol levels induced by RAI therapy over time. Results: The patients' ages ranged from 21 to 38 years, with a mean age of 31.15 ± 4.83 years. The median follow-up was 19 months (range 4-26 months). The median AMH levels were 3.25 ng/mL (range 0.32-17.42 ng/mL), 1 ng/mL (range 0.01-3.93 ng/mL), 1.13 ng/mL (range 0.08-6.12 ng/mL), and 1.37 ng/mL (range 0.09-6.1 ng/mL) before and at 3, 6, and 12 months after RAI therapy, respectively. The median FSH levels were 6.6 mIU/mL (range 3.78-15.5 mIU/mL), 5.83 mIU/mL (range 4.19-35.36 mIU/mL), 7.71 mIU/mL (range 4.24-16.25 mIU/mL), and 7.04 mIU/mL (range 4.93-19.96 mIU/mL) before and at 3, 6, and 12 months after RAI therapy, respectively. The AMH levels were higher before than after RAI therapy (p = 0.001). The AMH levels did not differ significantly between the three time points (p > 0.05). The FSH, LH, and estradiol levels were similar before and after RAI therapy (p > 0.05). Conclusion: AMH is considered an important marker of ovarian reserve. Ovarian reserve decreased after RAI therapy. More attention may be needed when considering RAI therapy for patients with reduced ovarian reserve.

Factors Associated with Dose Determination of Radioactive Iodine Therapy for Differentiated Thyroid Cancer

Radioactive iodine (RAI) therapy for differentiated thyroid cancer has been successfully used for more than 70 years. However, there is still plenty of controversy surrounding the use and doses of radioiodine. There is insufficient evidence to answer the questions. Recent American Thyroid Association (ATA) guidelines seem to favor low-dose RAI, based on recent clinical trials and meta-analyses. However, long-term follow-up data remains limited, and there are additional factors we should consider that might affect the efficacy of RAI therapy. Therefore, until sufficient data are available, it is necessary to remain cautious about determining RAI doses by considering multiple patient-specific variables.

Anti-Müllerian hormone in pre-menopausal females after ablative radioiodine treatment for differentiated thyroid cancer

PURPOSE

In recent years, anti-Mullerian hormone (AMH) has been considered a reliable index of ovarian reserve. There are few data on AMH values in thyroid cancer. The aim of this study was to evaluate AMH levels in pre-menopausal women with a history of low-risk thyroid cancer.

METHODS

Thirty-four women (aged 40.7 ± 6.7 years) were studied 7.1 ± 0.9 years after surgery and at least one RAI treatment. A group of 23 thyroid cancer women (41.6 ± 7.4 years) who had undergone only thyroidectomy served as controls. AMH, follicle-stimulating hormone (FSH) and estradiol were assayed on days 2-3, and prolactin and progesterone levels on days 21-24 of the menstrual cycle.

RESULTS

Pregnancy (RAI group 62%; control group 61%) and miscarriage rates (18% and 26%) were similar. AMH levels were similar in the RAI (10.7 ± 1.7 pmol/l) and control (17.5 ± 4.7 pmol/l) groups. Regular menses were reported in 41% and 52% of RAI and control subjects, respectively. Non-ovulatory cycles were noted in 26% and 35% of RAI and control women, respectively. AMH levels were found to be negatively correlated with age (RAI group P = 0.0003; control group P = 0.0001) and FSH, and positively correlated with progesterone, but not with the other hormonal parameters.

CONCLUSIONS

AMH should replace FSH in the evaluation of gonadal reserve in pre-menopausal thyroid cancer women. At present, age is the only predictor of AMH levels. About one out of two women with a history of thyroid cancer suffers from menstrual dysregulation, but infertility must be considered a low risk.

A Single Radioactive Iodine Treatment Has a Deleterious Effect on Ovarian Reserve in Women with Thyroid Cancer: Results of a Prospective Pilot Study

BACKGROUND

Women of reproductive age with differentiated thyroid cancer (DTC) often need radioactive iodine (RAI) treatment after surgery. In contrast to the well-documented effect of RAI on testicular function, the potential negative effects of this treatment on ovarian reserve have been largely dismissed. The objective of this pilot study was to examine the possibility that RAI treatment is deleterious to the ovarian reserve by prospectively measuring the concentration of anti-Müllerian hormone (AMH) after RAI treatment.

METHODS

Thirty premenopausal women (M_age = 34 years; range 20-45 years) with a new diagnosis of DTC scheduled to undergo RAI ablation were recruited for this study. All of them had TNM stage 1 disease (T1-3, N0, or N1, M0), and were scheduled to receive RAI activities ranging from 30 to 150 mCi. AMH was measured at baseline and at 3, 6, 9, and 12 months after the administration of RAI.

RESULTS

Of the 30 women, only 24 returned after the baseline assessment. RAI treatment resulted in a significant decrease in AMH concentrations at three months, from 3.25 ± 2.75 to 1.9 ± 1.74 ng/mL (p < 0.0001). Only partial recovery was subsequently documented. Eighty-two percent of subjects had final values below baseline levels, such that at one year, serum AMH was still 32% lower than prior to treatment (2.36 ± 1.88 ng/mL; p < 0.005). The only two continuous variables that correlated with the extent of AMH reduction at three months were the woman's age (r = 0.51; p = 0.02) and the age at menarche (r = 0.48; p = 0.03). Importantly, the RAI dose was not associated with the extent of AMH reduction and neither were smoking or the use of birth control pills. Older subjects (≥35 years) were significantly more likely to experience a marked AMH reduction at three months (63.7 ± 18.5% vs. 33.1 ± 29.2%; p = 0.01). The only predictor of recovery after one year was the extent of AMH decrease at three months: the lower the decline, the higher the chances for recovery.

CONCLUSIONS

RAI in DTC has a rapid and profound effect on ovarian reserve, with only a partial recovery potential. In an era of declining human fertility, it is of relevance to recognize the potentially adverse effect of RAI in women of reproductive age. AMH measurement may be useful as a tool in this decision-making process.

Early and late adverse effects of radioiodine for pediatric differentiated thyroid cancer

BACKGROUND

Radioiodine-131 (I131) therapy for differentiated thyroid cancer (DTC) is generally a safe and effective treatment, but it has some potential side effects, which have been well described in adults but less analyzed in children. Our aim was to describe early and late adverse events of radioactive I131 in pediatric patients.

METHODS

All consecutive patients ≤18 years treated for DTC in the period 1980-2015 were retrospectively analyzed for early and late side effects of radioiodine. Early side effects include nausea/emesis, radiation thyroiditis, sialadenitis, dry mouth, and transient bone marrow (BM) suppression. Late complications include permanent salivary gland dysfunction, permanent BM suppression, pulmonary fibrosis, second cancers, and fertility problems.

RESULTS

One hundred five pediatric patients were treated with I131 for DTC in our department for a total amount of 302 radioiodine treatments. In total, 127 early complications were recorded: 44 episodes of nausea/emesis; 30 sialoadenitis, 24 thyroiditis, 18 dry mouth, and 11 transient BM suppression. Early side effects were correlated with the amount of radioactivity administered in any treatment. Twelve children developed ≥1 late complication for a total of 20 complications: two permanent salivary gland dysfunction, four permanent BM suppression, five pulmonary fibrosis, four second malignancies, and five fertility alterations. Late events, except fertility alterations, were correlated with the number of therapies and cumulative activities of I131.

CONCLUSIONS

In conclusion, early side effects of I131 are associated with the amount of administrated activities of each treatment, while the late effects are correlated with the number of treatments and cumulative activities of radioiodine, except for fertility problems.

Low versus high radioiodine activity for ablation of the thyroid remnant after thyroidectomy in Han Chinese with low-risk differentiated thyroid cancer

AIM

The aim of this study was to compare the efficacy and adverse effects of radioiodine (¹³¹I) therapy between two groups of patients with low-risk differentiated thyroid cancer (DTC) who received 30 mCi or 100 mCi radioiodine for ablation of the thyroid remnant after total thyroidectomy.

METHODS

The study cohort was 173 patients, 85 of whom were given 30 mCi of radioiodine and the others were given 100 mCi of radioiodine. Follow-up involved neck ultrasonography, measurement of serum levels of thyroglobulin and whole-body scans to evaluate the response of radioiodine treatment. All patients were assessed for adverse effects.

RESULTS

Of the 173 patients, 170 (98.3%) patients finally achieved successful ablation. The prevalence of successful ablation was 77.6% in the low-dose group versus 71.5% in the high-dose group after the first dose administration (P=0.36), 79% in the low-dose group versus 88% in the high-dose group after the second dose administration (P=0.416), and 97.6% in the low-dose group versus 98.9% in the high-dose group after the final ablation (P=0.54). We found no significant differences between the two groups. No patient had an adverse effect with a severity grade ⩾2 and the prevalence of adverse effects in the high-dose group was higher than that in the low-dose group, especially for nausea, neck pain, and sore throat.

CONCLUSION

These data suggest that a low dose of radioiodine is as effective as a high dose of radioiodine for ablation of the thyroid remnant after total thyroidectomy for low-risk DTC. Moreover, low-dose radioiodine therapy is associated with a lower prevalence of adverse events.

Chinese Data of Efficacy of Low- and High-Dose Iodine-131 for the Ablation of Thyroid Remnant

BACKGROUND

Chinese data on the efficacy of low- and high-dose radioiodine for thyroid remnant are still absent. The aim of the study was to investigate whether a low dose of radioiodine is as effective as a high dose for remnant ablation in Chinese patients.

METHODS

Patients presenting for radioiodine ablation in the authors' department were included. Inclusion criteria were aged ≥16 years, total or near-total thyroidectomy, tumor-node-metastasis (TNM) stage of pT1-3, any N stage, and M0. All patients were randomly allocated to either the high-dose group of 3700 MBq or the low-dose group of 1850 MBq for remnant ablation. The response to treatment was defined as successful or unsuccessful after a six- to nine-month interval. Ablation was considered to be successful if patients fulfilled the following criteria: no tracer uptake in the thyroid bed on diagnosis whole-body scanning and a negative level of serum thyroglobulin.

RESULTS

There were 327 patients enrolled between January 2013 and December 2014. More than 95% had papillary thyroid cancer. Data could be analyzed for 278 cases (M_age = 44 years; 71.6% women), 155 in the low-dose group and 123 in the high-dose group. The rate of initial successful ablation was 84.2% in all patients, 82.6% in the low-dose group, and 86.2% in the high-dose group. There was no difference between the two groups (p = 0.509).

CONCLUSIONS

In Chinese patients with differentiated thyroid carcinoma, the low dose of 1850 MBq radioiodine activity is as effective as a high dose of 3700 MBq for thyroid remnant ablation.

Management of Differentiated Thyroid Cancer in Children: Focus on the American Thyroid Association Pediatric Guidelines

First introduced in 1946, radioactive iodine (I-131) produces short-range beta radiation with a half-life of 8 days. The physical properties of I-131 combined with the high degree of uptake in the differentiated thyroid cancers (DTCs) led to the use of I-131 as a therapeutic agent for DTC in adults. There are two indications for the potential use of I-131 therapy in pediatric thyroid disorders: nonsurgical treatment of hyperthyroidism owing to Graves' disease and the treatment of children with intermediate- and high-risk DTC. However, children are not just miniature adults. Not only are children and the pediatric thyroid gland more sensitive to radiation than adults but also the biologic behavior of DTC differs between children and adults as well. As opposed to adults, children with DTC typically present with advanced disease at diagnosis; yet, they respond rapidly to therapy and have an excellent prognosis that is significantly better than that in adult counterparts with advanced disease. Unfortunately, there are also higher rates of local and distant disease recurrence in children with DTC compared with adults, mandating lifelong surveillance. Further, children have a longer life expectancy during which the adverse effects of I-131 therapy may become manifest. Recognizing the differences between adults and children with DTC, the American Thyroid Association commissioned a task force of experts who developed and recently published a guideline to address the unique issues related to the management of thyroid nodules and DTC in children. This article reviews the epidemiology, diagnosis, staging, treatment, therapy-related effects, and suggestions for surveillance in children with DTC, focusing not only on the differences between adults and children with this disease but also on the latest recommendations from the inaugural pediatric management guidelines of the American Thyroid Association.

The preliminary clinical observation and analysis of childbearingage women with a history of iodine-131 treatment for Graves' disease

Whether radioactive iodine treatment of Graves' disease (GD) during pregnancy will increase pregnancy loss and affect fetal development is still a matter of concern. From May 2005 to December 2015, 2,276 childbearing-age women with GD received iodine-131 treatment in our departments and were retrospectively enrolled in our study. When some of them were found to have been pregnant, their thyroid functions were measured every 4 weeks, in addition, thyroid-stimulating hormone (TSH) was measured 6 weeks after delivery. When necessary, levothyroxine or propylthiouracil (PTU) was given in order to control their TSH levels during pregnancy. Finally, 69 pregnant women (29 ± 3.5 years old) and 1346 women who were not pregnant during the follow-up period were enrolled into this study. They were all hyperthyroid before or during pregnancy. Among 69 pregnant women, the administrated amount of iodine-131 was 254.9 ± 99.9 MBq. Fifty patients became subclinically hypothyroid after treatment and were administrated levothyroxine (55 ± 25 μg/d). Seven patients were diagnosed with subclinical hyperthyroidism during pregnancy and they received PTU (25 ± 12.5 mg/d). Twelve patients with normal thyroid function were also clinically followed. Among 69 women, 63 had a single birth, 3 had dizygotic twins, 2 had two pregnancies and 1 had a single twin birth. Sixty five babies were born full-term, while 9 were premature (4 ± 1 weeks early) with birth weight 3.2 ± 0.5 kg. Six new born babies were considered to be low birth weight infants (< 2.5 kg) while 5 were high birth weight (> 4 kg), but the weights of all the infants were within the normal range. During the period of observation to December 2015, all the infants were found to grow and develop normally. Among 1346 women who were not pregnant were in the further follow-up. Our study found no detrimental effects of the iodine-131 treatment in the pregnant women or their offspring so far.

Pregnancy Outcome After I-131 Therapy for Patients With Thyroid Cancer: A Nationwide Population-Based Cohort Study

The aim of this study was to evaluate the influence of I-131 therapy on pregnancy outcome in patients that received therapeutic I-131 doses for thyroid cancer in Taiwan.This nationwide population-based cohort study was based on data from 1998 to 2010 obtained from the Taiwanese National Health Insurance Research Database. We identified 11,708 women with thyroid cancer (≥ 15 and ≤ 50 years of age) by International Classification of Diseases, Ninth Revision, Clinical Modification codes. Patients were divided into 2 cohorts: I-131 therapy cohort and non-I-131 therapy cohort. The mean follow-up period was 6.08 years for the I-131 cohort and 6.87 years for the non-I-131 cohort. The case cohort and the control cohort comprised 775 and 716 pregnant patients, respectively.The overall incidence of pregnancy was significantly lower in the I-131 cohort (adjusted HR = 0.77, 95% CI = 0.70-0.86) and it was also observed when the patients were stratified according to age (HR = 0.73, 95% CI = 0.64-0.83 in 25-34 years; HR = 0.63, 95% CI = 0.49-0.82 in 35-44 years). Patients in the I-131 cohort had a lower successful delivery rate, particularly among patients in 25 to 34 years (OR = 0.60, 95% CI = 0.45-0.80). No significant difference was observed for adverse pregnancy conditions between 2 cohorts.I-131 therapy is associated with decreased pregnancy and successful delivery rates. The underlying mechanism likely involves physician recommendation, patient's psychological issue, and potential impact of I-131 treatment on reproductive health. Further investigation is needed.

2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations for therapeutic interventions. We developed a similarly formatted system to appraise the quality of such studies and resultant recommendations. The guideline panel had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, use of molecular markers, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to screening for thyroid cancer, staging and risk assessment, surgical management, radioiodine remnant ablation and therapy, and thyrotropin suppression therapy using levothyroxine. Recommendations related to long-term management of differentiated thyroid cancer include those related to surveillance for recurrent disease using imaging and serum thyroglobulin, thyroid hormone therapy, management of recurrent and metastatic disease, consideration for clinical trials and targeted therapy, as well as directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid nodules and differentiated thyroid cancer. They represent, in our opinion, contemporary optimal care for patients with these disorders.

Reproductive outcomes and nononcologic complications after radioactive iodine ablation for well-differentiated thyroid cancer

BACKGROUND

Radioactive iodine (RAI) ablation is frequently performed after initial surgery for well-differentiated thyroid cancer (WDTC). We examined the frequency and timing of childbirth as well as nononcologic complications after RAI ablation for WDTC on a population level.

METHODS

A retrospective cohort study of 25,333 patients (18,850 women) with WDTC was performed using the California Cancer Registry and California Office of Statewide Health Planning and Development database, 1999-2008. The primary outcomes were birthrate and median time to first live birth among women of childbearing age. Secondary outcomes were nononcologic diagnoses occurring outside the acute setting (>30 days) after ablation.

RESULTS

RAI ablation did not affect birthrate among women in the full dataset. However, in subgroup analyses, birthrate among women age 35-39 was significantly decreased in those who received RAI versus those who did not (11.5 versus 16.3 births per 1000 woman-years, p<0.001). Median time to first live birth after diagnosis of WDTC was prolonged among women who received RAI compared to those who did not (34.5 versus 26.1 months; p<0.0001). When 5-year age groups were examined individually, delay to first live birth was observed in women age 20-39 (p<0.05). This remained significant after adjustment for tumor characteristics, socioeconomic status, and marital status. The only nononcologic, nonreproductive adverse effect associated with RAI ablation was an increased rate of nasolacrimal stenosis (RR 3.44, p<0.0001).

CONCLUSIONS

RAI ablation is associated with delayed childbearing in women across most of the reproductive lifespan, and with decreased birthrate in the late reproductive years. The underlying mechanism likely involves physician recommendation to delay pregnancy, as well as a potential impact of RAI on both reproductive choice and reproductive health. Further investigation is merited.

The cyclophosphamide equivalent dose as an approach for quantifying alkylating agent exposure: a report from the Childhood Cancer Survivor Study

BACKGROUND

Estimation of the risk of adverse long-term outcomes such as second malignant neoplasms and infertility often requires reproducible quantification of exposures. The method for quantification should be easily utilized and valid across different study populations. The widely used Alkylating Agent Dose (AAD) score is derived from the drug dose distribution of the study population and thus cannot be used for comparisons across populations as each will have a unique distribution of drug doses.

METHODS

We compared the performance of the Cyclophosphamide Equivalent Dose (CED), a unit for quantifying alkylating agent exposure independent of study population, to the AAD. Comparisons included associations from three Childhood Cancer Survivor Study (CCSS) outcome analyses, receiver operator characteristic (ROC) curves and goodness of fit based on the Akaike's Information Criterion (AIC).

RESULTS

The CED and AAD performed essentially identically in analyses of risk for pregnancy among the partners of male CCSS participants, risk for adverse dental outcomes among all CCSS participants and risk for premature menopause among female CCSS participants, based on similar associations, lack of statistically significant differences between the areas under the ROC curves and similar model fit values for the AIC between models including the two measures of exposure.

CONCLUSION

The CED is easily calculated, facilitating its use for patient counseling. It is independent of the drug dose distribution of a particular patient population, a characteristic that will allow direct comparisons of outcomes among epidemiological cohorts. We recommend the use of the CED in future research assessing cumulative alkylating agent exposure.

Low- or high-dose radioiodine remnant ablation for differentiated thyroid carcinoma: a meta-analysis

CONTEXT

There is uncertainty over the dose of (131)I required for thyroid remnant ablation. Most previous studies have been inadequately powered to establish the best fixed dose of (131)I for effective ablation.

OBJECTIVE

The aim of the study was to assess the effects of low- vs high-dose regimens of radioiodine in thyroid remnant ablation for patients with differentiated thyroid carcinoma.

DATA SOURCES

Sources included the Cochrane Library, MEDLINE, EMBASE, and SCOPUS (all until September 2012).

STUDY SELECTION

Randomized controlled trials that assess the efficacy of low- or high-dose of radioiodine ablation of thyroid remnants were collected.

DATA EXTRACTION

Two authors performed the data extraction independently.

DATA SYNTHESIS

Nine randomized controlled trials involving 2569 patients were included. The 1100-MBq vs the 3700-MBq radioiodine showed no statistically significant difference in successful thyroid remnant ablation (risk ratio [RR], 0.91 [0.79 to 1.04]; P = .15), both the 1100 vs the 1850 MBq (RR, 0.95 [0.83 to 1.10]; P = .52) and the 1850 vs the 3700 MBq (RR, 1.00 [0.85 to 1.17]; P = .98) also showed no significant differences (95% confidence intervals were calculated for each estimate). Also, no significant differences existed in quality-of-life scores on the SF-36 between different (131)I-dose groups both on the day of ablation (RR, 0.15 [-0.65 to 0.96], P = .71; I(2) = 29%, P = .24) and 3 months after ablation (RR, -1.1 [-2.37 to 0.17], P = .09; I(2) = 22%, P = .26). A low dose of 1100 MBq radioiodine showed significant benefits in reducing adverse effects (total RR, 0.65 [0.55 to 0.77], P < .1; I(2) = 31%, P =.14) and shorter hospital isolation (RR, 0.4 [0.32 to 0.50]; P < .05).

CONCLUSIONS

The low dose of 1100 MBq radioiodine activity is sufficient for thyroid remnant ablation as compared to 3700 MBq radioiodine activity with similar quality of life, less common adverse effects, and a shorter hospital stay.

Radioiodine therapy in benign thyroid diseases: effects, side effects, and factors affecting therapeutic outcome

Radioiodine ((131)I) therapy of benign thyroid diseases was introduced 70 yr ago, and the patients treated since then are probably numbered in the millions. Fifty to 90% of hyperthyroid patients are cured within 1 yr after (131)I therapy. With longer follow-up, permanent hypothyroidism seems inevitable in Graves' disease, whereas this risk is much lower when treating toxic nodular goiter. The side effect causing most concern is the potential induction of ophthalmopathy in predisposed individuals. The response to (131)I therapy is to some extent related to the radiation dose. However, calculation of an exact thyroid dose is error-prone due to imprecise measurement of the (131)I biokinetics, and the importance of internal dosimetric factors, such as the thyroid follicle size, is probably underestimated. Besides these obstacles, several potential confounders interfere with the efficacy of (131)I therapy, and they may even interact mutually and counteract each other. Numerous studies have evaluated the effect of (131)I therapy, but results have been conflicting due to differences in design, sample size, patient selection, and dose calculation. It seems clear that no single factor reliably predicts the outcome from (131)I therapy. The individual radiosensitivity, still poorly defined and impossible to quantify, may be a major determinant of the outcome from (131)I therapy. Above all, the impact of (131)I therapy relies on the iodine-concentrating ability of the thyroid gland. The thyroid (131)I uptake (or retention) can be stimulated in several ways, including dietary iodine restriction and use of lithium. In particular, recombinant human thyrotropin has gained interest because this compound significantly amplifies the effect of (131)I therapy in patients with nontoxic nodular goiter.

Optimal surgical management of well-differentiated thyroid cancer arising in struma ovarii: a series of 4 patients and a review of 53 reported cases

BACKGROUND

Well-differentiated thyroid cancer arising in struma ovarii is rare. The optimal management of this entity remains undefined. Unilateral cystectomy, unilateral salpingo-oophorectomy (USO), or total abdominal hysterectomy with bilateral salpingo-oophorectomy (TAH/BSO), in addition to total thyroidectomy and radioactive iodine (RAI) ablation, have been employed by various groups. We hypothesized that in patients with thyroid cancer arising within struma ovarii, pelvic surgery alone would be sufficient, provided there is no evidence of gross extra-ovarian extension.

METHODS

We review a series of four patients from a single institution and 53 cases from the literature, comparing the extent of treatment and outcomes. Our literature review focused on low-risk patients with struma ovarii confined to the ovary, without evidence of gross extra-ovarian spread or distant metastases. Cumulative recurrence rate was determined by using the Kaplan-Meier method.

RESULTS

We report the treatment of four patients with well-differentiated thyroid cancer arising within struma ovarii. Patients underwent USO, BSO, or TAH/BSO. One patient underwent prophylactic total thyroidectomy in anticipation of RAI treatment, and was found to have a synchronous papillary thyroid carcinoma. All patients clinically remain without evidence of disease at a median follow-up of 9 (range 0.8-13) years. Treatment strategies in 53 cases from a review of the literature varied. The pooled cumulative recurrence rate of 57 cases with struma ovarii confined to the ovary was 7.5% at 25 years.

CONCLUSIONS

Thyroid cancer arising in struma ovarii is rare. Controversy exists regarding the extent of pelvic resection and management of the thyroid gland. In our series of four patients, all patients are alive without evidence of disease, and the 25-year recurrence rate of 57 cases was low (7.5%), despite a variety of approaches to surgical resection and adjuvant treatment. Extensive pelvic surgery and prophylactic total thyroidectomy to facilitate RAI therapy may be reserved for patients with gross extra-ovarian extension or distant metastases.

Clinical presentations of thyroid cancer patients with multiple primary cancers

BACKGROUND

In thyroid cancer patients with multiple primary cancers, primary cancers tend to be more aggressive.

AIMS

We analyzed multiple primary cancers in thyroid cancer patients and determined the differences between the incidence and the characteristics of primary cancers.

MATERIALS AND METHODS

A total of 3070 patients with thyroid cancer underwent a thyroidectomy and follow-up examination at a single medical center. The times of diagnosis of the primary cancers were categorized as antecedent, synchronous, or subsequent to the diagnosis of thyroid cancer.

RESULTS

After a mean follow-up period of 8.8 ± 0.5 yr, the presence of multiple primary cancers was histopathologically confirmed in 163 patients (5.3%). Patients with multiple primary cancers had a lower female-to-male ratio, an older mean age, advanced tumor-node-metastasis (TNM) stage, higher total mortality, and higher therapeutic radioactive iodide (131I) doses than patients without multiple primary cancers. Hematological malignancy and renal cell carcinoma, neither of which are among the 10 most common cancers observed in the general population of Taiwan, were the most common multiple cancers among women and men with thyroid cancer. Patient age, thyroid cancer tumor size, and thyroid cancer mortality in the antecedent, synchronous, and subsequent groups were not significantly different.

CONCLUSIONS

Patients with multiple primary cancers in advanced stages had shorter disease-free survival period after treatment. Thyroid cancer patients with multiple primary cancers should be closely followed up for the occurrence of other secondary cancers in order to improve total mortality.

Expression of benign and malignant thyroid tissue in ovarian teratomas and the importance of multimodal management as illustrated by a BRAF-positive follicular variant of papillary thyroid cancer

BACKGROUND

The most common type of ovarian germ cell tumor is the teratoma. Thyroid tissue, both benign and malignant, may be a component of an ovarian teratoma. Here we review this topic and illustrate major features by presenting multimodal management of a patient with BRAF-positive disseminated follicular thyroid cancer arising in an ovarian teratoma.

SUMMARY

Malignant thyroid tissue is often difficult to distinguish from benign thyroid tissue arising in ovarian teratomas. Preoperatively, an elevated thyroglobulin (Tg) level, laboratory or clinical evidence of hyperthyroidism, or ultrasonography appearance of "struma pearl" should prompt referral to oncologist for surgical management of a possibly malignant ovarian teratoma. Postoperatively, tumor tissue should be referred to pathologists experienced with differentiating benign from malignant struma ovarii. Once diagnosed, treatment of this rare condition should be handled by a team of specialists with combined treatment modalities. We cared for woman with disseminated thyroid cancer arising in an ovarian teratoma whose history illustrates the complexity of managing ovarian teratomas with malignant thyroid tissue. At age 33 she had an intraoperative rupture of an ovarian cyst, thought to be struma ovarii. During her next pregnancy, pelvic masses were noted; biopsies revealed well-differentiated papillary thyroid carcinoma, follicular variant. She was euthyroid, but had elevated serum Tg levels. Surgical staging demonstrated widely metastatic intraabdominal dissemination. A thyroidectomy revealed no malignancy. A post-(131)I treatment scan revealed diffuse uptake throughout the abdomen. She then developed abdominal pain and, on computed tomography, was found to have multiple intraabdominal foci of disease. Serum Tg was 264 ng/mL while on L-thyroxine for hypothyroidism and to obtain thyrotropin suppression. A 18 fluorodeoxyglucose positron emission tomography scan showed no pathological uptake. The tumor was found to be BRAF mutation positive (K601E). She underwent extensive secondary debulking and a second course of (131)I with lithium pretreatment. Posttreatment scan revealed diffuse abdominal uptake. Six months posttherapy, the patient is asymptomatic with a serum Tg of 18.1 ng/mL.

CONCLUSIONS

Aggressive multimodal management appears to be the most promising approach for malignant thyroid tissue arising in ovarian teratomas.

Guidelines for radioiodine therapy of differentiated thyroid cancer

INTRODUCTION

The purpose of the present guidelines on the radioiodine therapy (RAIT) of differentiated thyroid cancer (DTC) formulated by the European Association of Nuclear Medicine (EANM) Therapy Committee is to provide advice to nuclear medicine clinicians and other members of the DTC-treating community on how to ablate thyroid remnant or treat inoperable advanced DTC or both employing large 131-iodine ((131)I) activities.

DISCUSSION

For this purpose, recommendations have been formulated based on recent literature and expert opinion regarding the rationale, indications and contraindications for these procedures, as well as the radioiodine activities and the administration and patient preparation techniques to be used. Recommendations also are provided on pre-RAIT history and examinations, patient counselling and precautions that should be associated with (131)I iodine ablation and treatment. Furthermore, potential side effects of radioiodine therapy and alternate or additional treatments to this modality are reviewed. Appendices furnish information on dosimetry and post-therapy scintigraphy.

A systematic review examining the effects of therapeutic radioactive iodine on ovarian function and future pregnancy in female thyroid cancer survivors

BACKGROUND

For women with differentiated thyroid carcinoma (DTC), the effect of radioactive iodine (RAI) therapy on gonadal and reproductive function is an important consideration.

OBJECTIVE AND METHODS

We systematically reviewed controlled studies examining the gonadal and reproductive effects of RAI therapy in women and adolescents surviving DTC. We searched nine electronic databases. All abstracts and papers were independently reviewed by two reviewers.

RESULTS

After reviewing 349 unique citations and 61 full-text papers, 16 papers including data from 3023 women or adolescents with DTC were included. All studies were observational, with no long-term randomized control trial data. The age at first RAI treatment varied from 8 to 50 years and the cumulative activities of RAI administered for treatment varied from 30 to 1099 mCi. Transient absence of menstrual periods occurred in 8-27% of women within the first year after RAI, particularly in older women. In addition, RAI-treated women experienced menopause at a slightly younger age than women not treated with RAI. In the first year after RAI therapy, several studies reported increased rates of spontaneous and induced abortions. However, RAI treatment for DTC was generally not associated with a significantly increased risk of long-term infertility, miscarriage, induced abortions, stillbirths, or offspring neonatal mortality or congenital defects.

CONCLUSIONS

In female survivors of DTC, there is little observational evidence to suggest important adverse effects of RAI treatment on gonadal function, fertility or pregnancy outcomes beyond 12 months, with the exception of a possible slightly earlier age of menopause.

A case of metastatic struma ovarii treated with 131I therapy: focus on preservation of fertility and selected review of the literature

Struma ovarii is a rare monodermal ovarian teratoma composed predominantly of mature thyroid tissue. We describe herein the case of a 22-year-old woman who underwent a right salpingo-oophorectomy for struma ovarii at the age of 12 years, who was admitted 8 years later with signs and symptoms of a left pelvic tumor. Laparoscopy detected a left ovarian endometriotic cyst and multiple nodules on the pelvic peritoneum, right lateral abdominal wall, diaphragm, vesical plica and liver. The diagnosis was abdominal and pelvic widespread dissemination of recurrent struma ovarii, with features consistent with the follicular variant of papillary thyroid carcinoma. The patient was treated with a combination of conservative surgery and two 131I administrations (cumulative activity of 350 mCi after dosimetric evaluation). Because of the high degree of hormonogenesis shown by the metastases, the first administration was performed following use of recombinant human (rh) thyroid-stimulating hormone (TSH) to reach adequate TSH levels. To avoid the 'stunning effect' and to obtain high-quality scintigraphy, a whole-body scan was performed with 123I after rh-TSH and before the 131I therapy. We also discuss the potential role and the possible benefit of using gonadotropin-releasing hormone analogs and ovarian tissue cryopreservation to preserve fertility in women treated with 131I for pelvic metastases from malignant struma ovarii.

Low vs. high radioiodine activity to ablate the thyroid after thyroidectomy for cancer: a randomized study

Background

Radioactive iodine is commonly administered following thyroidectomy for differentiated thyroid carcinoma to ablate the thyroid remnant. The optimal administered activity of radioiodine is unknown.

Methodology/Principal Findings

Adult subjects (n = 160) diagnosed with papillary or follicular thyroid carcinoma were randomly allocated to receive either 1100 MBq (30 mCi) or 3700 MBq (100 mCi) activity of radioiodine (¹³¹I) following thyroidectomy. The study participants were prepared for ablation using thyroid hormone withdrawal. Ablation was considered successful when serum thyroglobulin concentration was less than 1 ng/mL and no uptake was present in ¹³¹I scan. Ablation was successful following one administration of radioiodine in 42 (52%; 95% CI, 41% to 63%) of the 81 evaluable study participants who received 1100 MBq, and in 43 (56%, 45% to 67%) of the 77 subjects who received 3700 MBq activity (P = .61). There was no difference between the groups in the numbers of repeat radioiodine treatments needed to complete ablation (P = .27). The higher activity was associated with more nausea and taste disturbances, and a longer stay in a radioprotected isolation unit. None of the participants died from thyroid cancer during a median follow up of 51 months; three subjects in the 3700 MBq group and none in the 1100 MBq group were diagnosed with distant metastases during follow-up. In a meta-analysis of four randomized studies that compared the 1100 and 3700 MBq activities, the 1100 MBq activity tended to be associated with a higher risk of unsuccessful ablation (relative risk 1.148, 95% CI 0.974 to 1.353, P =  .10).

Conclusions/Significance

The results provide no conclusive evidence that 3700 MBq activity is more effective for ablation of the thyroid remnant than 1100 MBq activity. The 3700 MBq activity is associated with more adverse effects.

Trial Registration

ClinicalTrials.gov NCT00115895

Malignant struma ovarii: good response after thyroidectomy and I ablation therapy

BACKGROUND

Malignant struma ovarii is a rare malignant germ cell tumor of the ovary. Due to the rarity of this disease, treatment has not been uniform throughout the published literature.

CASES

We present three cases of malignant struma ovarii. Following primary surgery, all were subsequently treated with thyroidectomy and (131)I ablation therapy, two patients as first line management, one following the occurrence of metastatic disease.

CONCLUSION

Histological diagnosis of malignant struma ovarii is similar to that of well differentiated thyroid carcinoma (WDTC). In line with the latest advice on treatment of WDTC, we believe that the best option for patients with malignant struma ovarii is surgical removal of the ovarian lesion followed by total thyroidectomy which allows the exclusion of primary thyroid carcinoma, and in addition, allows radioiodine ((131)I) ablation therapy for (micro) metastasis. After thyroidectomy, thyroglobulin can be used as a tumor marker for follow-up. Moreover, nuclear medicine imaging using radioiodine ((123)I) can be performed to demonstrate metastatic carcinoma. A multidisciplinary approach is essential.

Is adjuvant therapy useful in patients with papillary carcinoma smaller than 2 cm?

To evaluate tumor recurrence after total thyroidectomy in patients with single papillary carcinoma with size <or= 2 cm and restricted to the thyroid, we studied 136 consecutive patients divided into two groups according to postoperative management: no ablative therapy (n = 42) (group 1) and ablation with 1.1 GBq (n = 36) or 3.7 GBq (131)I (n = 58) (group 2). None of the patients were submitted to central-compartment (VI level) neck dissection. Thyroid-stimulating hormone (TSH) levels were > 0.5 mIU/L in >or=50% of the measurements in all patients. Complete remission (stimulated thyroglobulin (Tg) <or= 1 ng/mL, undetectable antithyroglobulin antibodies (TgAb), and negative imaging methods) was observed in 83% of the patients in group 1 and in 89% in group 2 (p = 0.4), and none of the patients presented apparent disease during follow-up (mean: 6 years). Posttherapy whole-body scanning was available in 74 patients, and none of them showed ectopic uptake. TgAb were still present in 7.1% of the patients in group 1 and in 8.5% in group 2 (p > 0.05). Six patients who still had stimulated Tg > 1 ng/mL (<5 ng/mL) showed a >50% decrease in comparison with Tg measured 12-24 months earlier. In conclusion, we suggest a more conservative approach with respect to central-compartment neck dissection, postoperative (131)I, and suppressive therapy in patients with small tumors restricted to the thyroid.

Differentiated Pediatric Thyroid Cancer: Correlates With Adult Disease, Controversies in Treatment

The biologic behavior of differentiated thyroid cancer can differ between adults and children, especially in those children younger than 10 years of age. Unlike adults, young children typically present with advanced disease at diagnosis. Despite this, children respond rapidly to therapy and have an excellent prognosis that is significantly better than that of their adult counterparts with advanced disease. In contradistinction to adults, children with thyroid cancer also have higher local and distant disease recurrences with progression-free survival of only 70% at 5 years, mandating life-long surveillance. Although thyroid cancer is the most common carcinoma in children, overall incidence is low, a factor that has prevented performance of a controlled, randomized, prospective study to determine the most efficacious treatment regimen in this age group. So, although extensively investigated, treatment of pediatric patients with differentiated thyroid cancer remains controversial. This article reviews the current controversies in the treatment of pediatric differentiated thyroid cancer, focusing on issues of optimal initial and subsequent therapy as well as that of long-term follow-up. Our approach to treatment is presented. In so doing, similarities and differences between adults and children with differentiated thyroid cancer as regards unique considerations in epidemiology, diagnosis, staging, treatment, therapy-related late effects, and disease surveillance are presented. The expanding use of and appropriate roles for thyrogen and fluorine-18-fluorodeoxyglucose positron emission tomography in disease evaluation and surveillance will be addressed.

Infertility and thyroid disorders

PURPOSE OF REVIEW

This review highlights the 'gap' in knowledge regarding the contribution of thyroid dysfunction in reproduction. Thyroid dysfunction, which is quite prevalent in the population affects many organs including the male and female gonads, interferes with human reproductive physiology, reduces the likelihood of pregnancy and adversely affects pregnancy outcome, thus becoming relevant in the algorithm of reproductive dysfunction.

RECENT FINDINGS

Although menstrual irregularities are common, ovulation and conception can still occur in hypothyroidism, where thyroxine treatment restores a normal menstrual pattern and reverses hormonal changes. Subclinical hypothyroidism may be associated with ovulatory dysfunction and adverse pregnancy outcome. Thyroid autoimmunity increases the miscarriage rate, and thyroxine treatment does not seem to protect. Menstrual disturbances, frequent in thyrotoxicosis are restored following treatment. In males, thyrotoxicosis has a significant but reversible effect on sperm motility. Although radioactive Iodine (I) in ablation doses may transiently affect the gonads, it does not decrease fertility or increase genetic malformation rate in the offspring.

SUMMARY

Awareness of the thyroid status in the infertile couple is crucial, because of its significant, frequent and often reversible or preventable effect on infertility. Many aspects of the role of thyroid disorders however in infertility need further research.

Premature menopause in survivors of childhood cancer: a report from the childhood cancer survivor study

BACKGROUND

Childhood cancer survivors who retain ovarian function after completing cancer treatment are at increased risk of developing premature menopause, defined as cessation of menses before age 40 years. However, published data pertaining to the risk and frequency of premature menopause are limited.

METHODS

We assessed the incidence of and risk factors for premature menopause in 2819 survivors of childhood cancer who were older than 18 years and were participants in the multicenter Childhood Cancer Survivor Study (CCSS). The comparison group was 1065 female siblings of participants in the CCSS. A multiple Poisson regression model was constructed to determine risk factors for nonsurgical premature menopause. All statistical tests were two-sided.

RESULTS

A total of 126 childhood cancer survivors and 33 control siblings developed premature menopause. Of these women, 61 survivors (48%) and 31 siblings (94%) had surgically induced menopause (rate ratio [RR] = 0.8, 95% confidence interval [CI] = 0.52 to 1.23). However, the cumulative incidence of nonsurgical premature menopause was higher for survivors than for siblings (8% versus 0.8%; RR = 13.21, 95% CI = 3.26 to 53.51; P<.001). A multiple Poisson regression model showed that risk factors for nonsurgical premature menopause included attained age, exposure to increasing doses of radiation to the ovaries, increasing alkylating agent score (based on number of alkylating agents and cumulative dose), and a diagnosis of Hodgkin lymphoma. For survivors who were treated with alkylating agents plus abdominopelvic radiation, the cumulative incidence of nonsurgical premature menopause approached 30%.

CONCLUSIONS

The results of this study will facilitate counseling current survivors about their future risk of premature menopause and aid in designing new regimens that seek to diminish late ovarian toxicity.

[Safety of radioiodine therapy in patients with thyroid carcinoma younger than 21 years]

We studied 20 patients with differentiated thyroid carcinoma undergoing radioiodine therapy (> or = 100 mCi dose) before the age of 21: 10 patients without distant metastases received a mean dose of 145 mCi and 10 with lung involvement received 270 mCi. One or more years after ablative therapy, xerostomia was present in two patients but was not accompanied by more severe complications such as oral ulcers or fissures, and 99mTcO4- scintigraphy confirmed salivary dysfunction. One patient showed keratoconjunctivitis sicca. Blood counts did not reveal abnormalities caused by radioiodine therapy. FSH was normal in 18 patients. Patients with elevated levels had received radioiodine just over a year ago and repetition of the exam after 6 months showed that FSH had returned to normal. The 6 male patients had normal LH and testosterone levels. Analysis did not reveal signs of pulmonary fibrosis secondary to treatment in the 10 cases with iodine-accumulating metastases in this organ. Our data suggest that ablative therapy employing a dose of 100 to 300 mCi is safe in young individuals, but persistent complications such as salivary dysfunction and conjunctivitis may occur.

Thyroid carcinoma

Thyroid carcinomas are fairly uncommon and include disease types that range from indolent localised papillary carcinomas to the fulminant and lethal anaplastic disease. Several attempts to formulate a consensus about treatment of thyroid carcinoma have resulted in published guidelines for diagnosis and initial disease management. Multimodality treatments are widely recommended, although there is little evidence from prospective trials to support this approach. Surgical resection to achieve local disease control remains the cornerstone of primary treatment for most thyroid cancers, and is often followed by adjuvant radioiodine treatment for papillary and follicular types of disease. Thyroid hormone replacement therapy is used not only to rectify postsurgical hypothyroidism, but also because there is evidence to suggest that high doses that suppress thyroid stimulating hormone prevent disease recurrence in patients with papillary or follicular carcinomas. Treatment for progressive metastatic disease is often of limited benefit, and there is a pressing need for novel approaches in treatment of patients at high risk of disease-related death. In families with inherited thyroid cancer syndromes, early diagnosis and intervention based on genetic testing might prevent poor disease outcomes. Care should be carefully coordinated by members of an experienced multidisciplinary team, and patients should be provided with education about diagnosis, prognosis, and treatment options to allow them to make informed contributions to decisions about their care.

Testicular dose and fertility in men following I(131) therapy for thyroid cancer

OBJECTIVE

Young adults with differentiated thyroid cancer are treated with high doses of radioiodine and have an excellent long-term prognosis. However, there is limited information on the effects of this treatment on the gonads and fertility in male patients. We have reviewed the outcome of treatment in our centre with respect to male fertility. We have also assessed directly the radiation dose received by the testes.

DESIGN

Retrospective analysis of males attending the thyroid clinic at the Royal Marsden Hospital for treatment of differentiated thyroid cancer. A prospective study was also performed to assess radiation dose to testes in 14 consecutive patients attending for thyroid cancer treatment.

PATIENTS

Males under the age of 40 years at the time of treatment with a minimum of 3 years follow-up.

MEASUREMENTS

Number of children fathered by patients and number of congenital malformations. For the prospective study: gonadal function assessed by serum FSH, LH and testosterone measurements; radiation dose to the testes (Gy) measured by thermoluminescent dosimetry.

RESULTS

Fertility was assessed in 122 men with a median follow-up of 21 years (range 3-39) of whom 93 were under active follow-up. One hundred and six children were fathered by 59 patients; the remainder had no wish to have children. No major malformations were reported. Of these 59 patients, 12 had received a single 3 GBq ablation dose, 19 had been treated with up to 14 GBq radioiodine and 28 had received up to 44 GBq. In 14 patients followed prospectively, the median estimated radiation dose to each testis was 6.4 cGy following 3 GBq, 14.1 cGy following 5.5 GBq and 21.2 cGy following 9.2 GBq. There was a transient elevation in serum FSH after radioiodine which normalized within 9 months from the last administration.

CONCLUSIONS

Radioiodine treatment for thyroid cancer may result in transient impairment of gonadal function. The radiation dose absorbed by the testis after a single ablative dose of radioiodine is well below that associated with permanent damage to germinal epithelium and the risk of infertility in these patients is minimal. Patients requiring multiple administrations for persistent or metastatic thyroid cancer may be at greater risk of gonadal damage although even in this group, we found no evidence of infertility.

Lack of impact of radioiodine therapy in tg-positive, diagnostic whole-body scan-negative patients with follicular cell-derived thyroid cancer

Several reports have suggested a benefit from radioactive iodine (RAI) therapy in Tg-positive, whole-body scan-negative patients with follicular cell-derived thyroid cancer, who were said to have high rates of visualization of uptake in metastases after therapeutic doses of RAI. We sought to evaluate the rate of visualization of RAI uptake in these patients and determine the effect of such therapy on tumor progression and Tg levels. We studied 24 consecutive patients who had been treated with high-dose RAI, four of whom had no evidence of metastasis or persistent cancer. Our results showed that four patients had some uptake in posttherapy scans: in the neck, lung, and mediastinal metastases in one patient, in the thyroid remnant in two, and in a possible neck microrecurrence in one. In 13 patients with macrometastases-tumors 1 cm or greater-tumors progressed and serum Tg increased; five have died of thyroid cancer. The disease remained stable in the seven patients with micrometastases. We concluded that in high-risk patients with follicular cell-derived thyroid cancer with high Tg levels and negative diagnostic whole-body scans, only a small number showed meaningful uptake after high doses of RAI. Therefore, widespread use of empiric RAI therapy for such patients who have a large tumor burden should not be encouraged.