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Published in final edited form as: Best Pract Res Clin Endocrinol Metab. 2019 Nov 22;34(4):101363. doi: 10.1016/j.beem.2019.101363

Thyroid Nodules and Cancer during Pregnancy, Post-partum and Preconception Planning: Addressing the Uncertainties and Challenges

Maria Papaleontiou 1, Megan R Haymart 2
PMCID: PMC7242146  NIHMSID: NIHMS1545315  PMID: 31786102

Abstract

Thyroid nodules and thyroid cancer have become increasingly common worldwide. When discovered during pregnancy, they pose unique diagnostic and therapeutic challenges for both the treating physician and the patient. The benefits of treatment should be carefully weighed against risks that may adversely impact maternal and fetal health. In this review, we present current knowledge and controversies surrounding the management of thyroid nodules and thyroid cancer in pregnancy, in the post-partum period and during preconception planning.

Keywords: Thyroid nodules, thyroid cancer, pregnancy, preconception planning

A. INTRODUCTION

Thyroid nodules and thyroid cancer have become increasingly common worldwide, with a majority occurring in women of childbearing age [1-4]. Several physiologic changes occur in the thyroid gland during pregnancy. These changes consist of an increase in the human chorionic gonadotropin (hCG) level, which carries some homology with thyroid stimulating hormone (TSH), as well as an increase in circulating estrogen levels, which indirectly result in a rise of serum thyroxine binding globulin [5]. This leads to an increase in thyroid gland size by 10% in iodine-sufficient and up to 40% in iodine-deficient countries, an increased daily iodine requirement and an increased production of thyroid hormones by approximately 50% [6]. The unclear role of these physiologic changes in the progression of thyroid nodules and cancer, uncertainties surrounding optimal management of thyroid nodules and cancer in pregnancy, in the post-partum period and during preconception planning, and the imperative to ensure maternal and fetal well-being, present clinicians with unique challenges. These challenges arise both in terms of choice of diagnostic tests and treatment, as well as timing of intervention, often leading to cautious decision-making and potentially modifying or delaying plans for conception. The benefits of treatment should always be carefully weighed against risks that may adversely impact maternal and fetal health.

We provide a comprehensive review of the literature to date and highlight current diagnostic and management recommendations for the clinician caring for women with thyroid nodules and thyroid cancer during pregnancy and the post-partum period. We review the epidemiology of thyroid nodules and their likelihood of progression to thyroid cancer during pregnancy, as well as their diagnosis and management. We subsequently focus on progression, recurrence risk and prognosis of differentiated thyroid cancer in pregnancy and management considerations. Finally, we outline considerations for the post-partum period and provide guidance for preconception planning and counseling.

B. THYROID NODULES

Epidemiology and Likelihood of Progression to Thyroid Cancer

Several studies have examined the prevalence of thyroid nodules during pregnancy using neck ultrasonography [7-10]. Prevalence ranged between 3 and 30% and correlated with increasing age and parity [7-10]. It has been postulated that pregnancy is associated with an increase in the size of preexisting thyroid nodules, as well as new thyroid nodule formation. In relation to nodule growth, one study showed a doubling in nodule size during pregnancy [7], while another study reported increased nodular volume during pregnancy which was transient [8]. Additionally, up to 20% of women with a thyroid nodule detected in the first trimester of pregnancy developed another nodule before delivery [7, 9].

Whether thyroid nodules discovered in pregnancy are associated with a higher incidence of malignancy is uncertain. Four studies with markedly different methods attempted to explore this issue. The only prospective study, conducted by Kung AW et al, evaluated 221 healthy Southern Chinese women in the first trimester of their pregnancy. They found that the incidence of thyroid nodular disease increased from 15.3% in the first trimester to 24.4% three months post-partum. No malignancy was detected in the 34 women who had one or more thyroid nodules [9]. Three cross-sectional single-institution studies examined rates of malignancy in thyroid nodules discovered during pregnancy [11-13]. The prevalence of malignancy in these studies was between 12% and 43%. However, these studies are limited by their retrospective nature and selection bias, as these were women referred for thyroid nodule management at major tertiary academic centers and may not be representative of the general pregnant population. Therefore, the prevalence of thyroid cancer in thyroid nodules discovered during pregnancy in these studies is likely over-reported.

Diagnosis and Management

Similar to the general population, initial evaluation of thyroid nodules in pregnant women should include a careful history and physical examination [6, 14]. Family history of thyroid cancer and exposure to head, neck and/or cranial radiation or ionizing radiation should be recorded. Physical exam should include a thorough inspection and palpation of the neck. A serum TSH should be measured, which is most frequently normal in patients with thyroid nodules. A low TSH measurement in non-pregnant women may suggest a hyperfunctioning nodule and should be evaluated with a radionuclide thyroid scan. However, this may present unique challenges during pregnancy as serum TSH physiologically decreases during early gestation due to a rise in beta-hCG (which mimics TSH activity and bind to the TSH receptor). Additionally, even though no studies have specifically examined whether scintigraphy with scanning doses of either technetium pertechnetate or 123I has adverse fetal effects, current guidelines indicate that both are contraindicated in pregnancy. This is because all maternal radionuclides can potentially result in fetal irradiation from placental transfer and external irradiation from maternal organs, such as the bladder [6, 15]. Routine measurement of baseline serum thyroglobulin or calcitonin is not recommended [6].

Neck ultrasound remains the most accurate and safe imaging modality for detecting thyroid nodules, assessing their pattern and features, and surveying cervical lymph nodes in pregnancy. Sonographic features of thyroid nodules should be correlated to malignancy risk potential according to a risk stratification algorithm (e.g. American Thyroid Association guidelines, TI-RADS, etc.) in order to guide decision-making regarding fine-needle aspiration (FNA) biopsy [16, 17].

Fine-needle aspiration is the most accurate and cost-effective method in the evaluation of thyroid nodules that meet criteria for biopsy and is the procedure of choice in pregnant women with a normal or high TSH. Studies to date have shown that FNA is a safe procedure and may be performed in any trimester [18-23]. As pregnancy does not seem to modify cellular appearance at the microscopic level, the same diagnostic criteria for cytologic evaluation as in non-pregnant patients are applied [14]. A retrospective study by Tan GH et al (N=40) showed good concordance between cytology from FNAs performed during pregnancy and subsequent histopathological findings in those women who underwent surgery, indicating that pregnancy does not alter the outcome [11]. Therefore, patient preference for timing of FNA should be taken into account, as it can safely be performed either during pregnancy or post-partum.

Even though pregnancy has been considered a risk factor for progression of thyroid nodular disease, and some studies have shown modest shrinkage of up to 20% of nodules with suppressive doses of levothyroxine, this practice is not recommended due to the potential risks of iatrogenic thyrotoxicosis [6, 16, 24]. Thyroid nodules that are found to be cytologically benign in pregnancy should be managed similarly to those in the general population [6, 16]. Pregnant women with cytologically indeterminate thyroid nodules (atypia of undetermined significance/follicular lesion of undetermined significance, suspicious for follicular neoplasm, or suspicious for malignancy) may be followed conservatively during pregnancy, especially since there are no prospective studies evaluating the prognosis of these women, and because the majority of these nodules are later found to be benign [6]. Additionally, none of the diagnostic molecular markers utilized for evaluation of indeterminate thyroid nodules to improve preoperative risk assessment in non-pregnant women have been validated in pregnant women. In theory, pregnancy can lead to changes in RNA expression in the maternal thyroid and alter performance of RNA-based gene expression tests. DNA-based tests are theoretically less likely to be influenced by gestation [25]. Overall, due to lack of evidence and concerns regarding accuracy, molecular testing cannot currently be recommended for evaluation of indeterminate thyroid nodules in pregnancy [6].

C. THYROID CANCER

Differentiated Thyroid Cancer (DTC)

When differentiated thyroid cancer (DTC) is diagnosed in early pregnancy, it should be closely monitored by ultrasound [6]. The effect of pregnancy on DTC progression, recurrence risk and prognosis should be considered and is further discussed below. The option of active surveillance, timing of surgery, perioperative risks, effect of radioactive iodine on fertility and future pregnancies, and TSH suppression should all be addressed with the patient. All available studies to date have focused on papillary thyroid cancer when addressing DTC management in pregnancy.

Progression, Recurrence Risk and Prognosis

Whether pregnancy has an impact on the progression and prognosis of newly diagnosed DTC, and whether it confers a higher risk of recurrence later, remains a heated debate. This is mainly due to a limited number of available studies addressing these issues, many of which were conducted decades ago, and due to lack of randomized controlled trials.

Several studies assessed overall and disease-specific survival in women diagnosed with DTC in pregnancy or during the first year after delivery compared to non-pregnant women [26-31]. Four studies analyzed data from large databases and did not find a difference in survival between the two groups [26-28, 30]. However, more than 99% of pregnant and non-pregnant women had stage I disease. There was consensus among all studies that timing of surgery, be it during pregnancy or post-partum, did not affect survival [26-29, 31].

Six retrospective studies to date demonstrated that pregnancy did not significantly accelerate disease progression in women who were treated for DTC and subsequently had one or more pregnancies [32-37]. All of these studies were limited by small sample size (N=22-235). In summary, these studies showed that there was no increased risk of recurrence in women who had suppressed thyroglobulin levels (which varied between studies: <0.9 ng/ml to <2 ng/ml) and negative neck ultrasound prior to conception [35-37]. The largest of these studies by Rakhlin et al (N=235) evaluated whether pre-pregnancy response to therapy status, as recommended by the 2015 American Thyroid Association guidelines, is a predictor of pregnancy-associated structural disease progression in women previously treated for DTC who had a term pregnancy. None of the patients with an excellent, indeterminate or biochemical incomplete response to therapy prior to pregnancy developed sonographically evident structural disease following delivery. Women who had persistent disease before conceiving were more likely to have structural disease progression of their DTC, with only a minority requiring additional therapy [32]. Other studies showed similar findings [35, 37].

Taking into consideration the aforementioned findings, current recommendations for surveillance of previously treated DTC in pregnancy advocate for serial neck ultrasounds and thyroglobulin measurements in pregnant women with DTC and either a biochemical or structural incomplete response to treatment, or those who have known active persistent or recurrent disease. However, for women with previously treated low-risk DTC who have no evidence of residual disease as evidenced by undetectable serum thyroglobulin levels prior to pregnancy, and neck sonography, serial thyroglobulin monitoring is not required during gestation [6].

Management

Active Surveillance:

Prospective studies from Japan have shown that active surveillance is an acceptable alternative management approach to surgery for papillary microcarcinomas (tumor size <1 cm), without sonographically evident suspicious cervical lymph nodes or extrathyroidal extension [38, 39]. A group of Japanese investigators examined a series of 50 pregnant women with low-risk papillary microcarcinoma undergoing active surveillance, as a follow-up to a smaller study [40, 41]. They found that only 8% (4/50) of patients exhibited tumor growth of ≥3 mm, 2% (1/50) exhibited tumor shrinkage by ≥3 mm and the remaining 90% (44/50) patients showed stable disease. None of the women developed nodal metastatic disease during pregnancy [40]. Therefore, despite growth of some papillary microcarcinomas during pregnancy, these patients continue to have an excellent prognosis, and may undergo active surveillance during future pregnancies with close observation. Neck ultrasounds should be performed each trimester during pregnancy in women with papillary microcarcinoma who are under active surveillance [6].

Surgery:

Surgery is traditionally the initial treatment for DTC. However, the decision to pursue surgery during pregnancy versus delay until post-partum depends on a variety of factors, including impact on prognosis and risk of maternal and fetal/neonatal complications. Women who are diagnosed with DTC during early pregnancy, should be counseled on the benefits and risks of having thyroid surgery during pregnancy versus post-partum. Several studies, albeit with small sample sizes, assessed the impact of thyroidectomy on the pregnant woman and fetus, with most surgeries taking place in the second trimester [11, 16, 42-48]. No maternal or fetal complications were reported in any of these studies. One exception is a population-based, retrospective cross-sectional study of clinical and economic outcomes after thyroid and parathyroid surgery in pregnant women conducted by Kuy S et al. The study sample consisted of 201 pregnant women from the Health Care Utilization Project Nationwide Inpatient Sample who underwent thyroid (n=165) and parathyroid (n=36) surgery. Of the women that underwent thyroid surgery, 46% had thyroid cancer. The authors found that the fetal complication rates were 5.5% and maternal complication rates were 4.5%. On multivariable analysis, pregnancy was an independent predictor of higher endocrine (maternal hypoparathyroidism, hypocalcemia, tetany and recurrent laryngeal nerve injury) and general complication rates (odds ratio 2; p<0.001), longer adjusted length of hospital stay (0.3 days longer, p<0.001) and higher adjusted hospital costs ($300, p<0.001) [49]. The results of this study should be carefully interpreted as there were significant baseline differences between the pregnant and non-pregnant women groups. For example, pregnant women were more likely to have urgent or emergent hospital admissions for any reason and were more likely to have government insurance compared to the non-pregnant group.

More recently, a retrospective study compared the clinicopathological features and outcomes of 24 women with DTC who underwent surgery during the second trimester of pregnancy, to those of 21 women who underwent surgery within one year of delivery. No surgical complications, no miscarriages or birth defects were reported in either group, leading the authors to conclude that surgery can safely be carried out in the second trimester [50].

In general, if surgery is to be pursued in pregnancy, it is agreed that it should be performed in the second trimester, as the risks for miscarriage and preterm labor are lowest during this time [51]. Currently, guidelines indicate that surgery may be an option in the second trimester for the following three reasons: 1) if there is a substantial growth of the cancer, defined as 50% increase in volume and 20% in diameter in two dimensions, 2) if cytoligically-proven metastatic cervical lymph nodes develop or 3) if DTC diagnosed before 24-26 weeks of gestation is advanced stage [6, 16]. For pregnant women with non-aggressive DTC, surgery after delivery is recommended.

Radioactive Iodine:

It is well established that 131I crosses the placenta and if given after 12-13 weeks’ gestation accumulates in the fetal thyroid [52]. This results in fetal/neonatal hypothyroidism. Therefore, administration of 131I in pregnancy is contra-indicated.

Thyroid Hormone Management:

For patients treated for DTC, target ranges for TSH concentrations should be based initially on the risk of recurrence determined by surgical pathology and subsequently modified depending on response to treatment [16]. Particularly for patients who are at high or intermediate risk for recurrence according to the 2015 American Thyroid Association guidelines and the European Thyroid Association consensus, TSH should be suppressed or maintained below the normal range [16, 53]. In view of solid evidence that subclinical hyperthyroidism does not lead to any maternal or neonatal adverse outcomes [54], it is reasonable to maintain the same degree of TSH suppression in pregnancy as preconception, taking into account a close to 30% increase in thyroid hormone replacement requirement during pregnancy [55, 56]. Careful monitoring of thyroid function tests should be undertaken to avoid hypothyroidism and unnecessary overt hyperthyroidism. Serum TSH should be checked every 4 weeks until 16-20 weeks of gestation, and subsequently at least once between weeks 26 and 32 [6].

Tyrosine Kinase Inhibitors (TKIs):

There are currently three TKIs approved by the Federal Drug Administration (FDA) (Category D) and the European Medicines Agency (EMA) for use in patients with advanced metastatic differentiated thyroid cancer: sorafenib, lenvatinib and cabozantinib. There are currently no human studies evaluating the effects of these medications in pregnancy. However, in animal studies all three medications exhibited teratogenicity and embryo toxicity when given in doses lower than the recommended human dose [57]. Both in Europe and the United States, the recommendation is that TKI use in pregnancy must always be guided by careful assessment of maternal and fetal benefits and risks. The FDA recommends that pregnancy should be avoided while taking sorafenib, explicitly recommends contraception for women taking lenvatinib, while no additional special advisories are listed for cabozantinib [57]. Overall, pregnancy testing and effective contraception in women and men of childbearing potential is recommended prior to initiation of TKI therapy [6].

Medullary and Anaplastic Thyroid Cancer

No studies to date have examined the effect of pregnancy on medullary or anaplastic thyroid cancer and management of these cancers during gestation remains a challenge. Current guidelines advocate for surgery to be strongly considered in the second trimester if FNA cytology of a thyroid nodule is diagnostic of medullary or anaplastic thyroid cancer, as delaying treatment will likely lead to worse outcomes [6, 58]. Considerations regarding the use of TKIs in pregnancy for treatment of medullary thyroid cancer are similar to those discussed above for advanced DTC.

D. CONSIDERATIONS FOR THE POST-PARTUM PERIOD

Evaluation and management of thyroid nodules in the post-partum period is the same as in the non-pregnant patient.

If thyroid cancer is diagnosed in the post-partum period, it is important to balance benefits and risks of treatments and to strategize optimal timing for surgery and/or radioactive iodine. Special considerations should be taken into account when caring for breastfeeding or lactating women with thyroid cancer in the post-partum period. The use of 131I is absolutely contraindicated during lactation as it has a long half-life (8 days) and concentrates in breast milk. The half-life of 123I is shorter (13 hours), and if used in lactating women, breast milk should be pumped and discarded for 3-4 days [6, 59]. Use of Tc-99m pertechnetate also requires breastfeeding women to pump and discard breast milk for one day [6]. Ideally, breastfeeding should be discontinued for 3 months prior to 131I administration. The effect of maternal TSH suppression on lactation remains uncertain [6].

E. PRECONCEPTION PLANNING AND COUNSELING

As 3 out of 4 cases of thyroid cancer occur in women, with 36% of all thyroid cancers being in women younger than 45 years old, pregnancy planning and management of thyroid cancer remains an important issue in women of childbearing age [3, 4, 60].

Interestingly, a large retrospective cohort study examined the reproductive outcomes of 18,850 women with DTC, using the California Cancer Registry and California Office of Statewide Health Planning and Development database from 1999 to 2008. This study found that there was a delay to first live birth in women who received radioactive iodine as part of their DTC treatment, compared to those who did not (median time 34.5 versus 26.1 months; p<0.001). When controlling for tumor characteristics, socioeconomic status and marital status, delay to first birth persisted for women aged 20-39 years (p<0.05). This led to decreased birth rates in the late reproductive years [61]. Similar conclusions were drawn from a population-based Taiwanese study [62]. These results are thought to be due to physician recommendation to delay pregnancy following radioactive iodine treatment and/or potential impact of radioactive iodine on reproductive health. However, contrary to these findings, a study of 2,360 women diagnosed with DTC between 15 and 39 years of age, of which 53% received radioactive iodine, did not find a significant difference in first birth rates between the women who were treated with radioactive iodine and those who were not [63].

In addition to the concern that physicians or patients may be delaying pregnancy for thyroid cancer treatment, there is also a theory that thyroid cancer treatment may impact future pregnancies. Uncertainty exists as to whether therapeutic doses of radioactive iodine (131I) for DTC may have an effect on subsequent pregnancies. Several studies examined the possible effects of radioactive iodine on gonadal function and the outcome of pregnancies that followed treatment [64-69]. The majority of studies did not find an increased risk of infertility in the first year post-partum. One study showed transient amenorrhea or menstrual irregularities in 30% of women who received therapeutic 131I, which resolved within one year of delivery [70]. Two studies (N=30-45) found that women who underwent radioactive iodine treatment for DTC exhibited a reduction in anti-Müllerian hormone levels, a marker of ovarian reserve, with only partial recovery after a year [68, 71]. Finally, a smaller study (N=23) found no difference in anti-Müllerian hormone levels between those treated with radioactive iodine and those who were not [69]. Furthermore, subsequent pregnancies were shown to be safe in all studies, without increased rates of spontaneous abortions, stillbirths, preterm births, congenital malformations, low birth weight or neonatal mortality in the first year of the neonates’ life [64-67, 70, 72]. In conclusion, it is recommended that pregnancy should be ruled out prior to radioactive iodine treatment. However, depending on the woman’s age and desire to pursue pregnancy, and in view of the possible deleterious effects of 131I on ovarian reserve, the option of delaying radioactive iodine treatment to fulfill plans for pregnancy should be discussed in women with low-to-intermediate risk DTC. When therapeutic doses of 131I are administered, pregnancy should be deferred for at least 6 months [6, 73, 74]. This delay is to ensure that thyroid hormonal control is stable, as radioactive iodine treatment may lead to suboptimal thyroid hormone control during the month following administration.

Considering that the majority of women with a history of DTC are on thyroid hormone replacement, they should be counseled regarding the need for an approximately 30% increase in thyroid hormone requirement should they become pregnant. Additionally, as there is no evidence that subclinical hyperthyroidism leads to any maternal or neonatal adverse outcomes, the same degree of TSH suppression in pregnancy as preconception should be maintained for women with DTC [54].

Finally, women of childbearing age with a germline mutation of the RET oncogene with or without clinically apparent medullary thyroid cancer, who are either trying to conceive or are pregnant, should seek genetic counseling. Counselors should discuss preconception, options of pre-implantation and/or prenatal genetic diagnostic testing with all RET mutation carriers, especially those with MEN2B [75-81]. If a woman does not wish to undergo prenatal RET mutation testing, genetic counseling and genetic testing of the baby should be offered.[6] A pheochromocytoma should always be excluded in women with MEN2A or MEN2B who are seeking to become pregnant or are pregnant. If a pheochromocytoma is diagnosed during pregnancy, it should be resected prior to the third trimester, whenever possible [6, 58].

Recommendations regarding preconception planning and counseling in women with thyroid cancer are outlined in Table 1 to provide guidance for clinicians caring for them.

Table 1.

Recommendations regarding Preconception Planning and Counseling in Women with Thyroid Cancer

Setting Recommendation
 • Radioactive iodine treatment for DTC  • For low-to-intermediate DTC patients consider delaying radioactive iodine treatment to fulfil plans for pregnancy depending on woman’s age and desire to conceive
 •  Pregnancy should be ruled out prior to radioactive iodine treatment
 • When therapeutic doses of 131I areadministered, pregnancy should be deferred for at least 6 months
 • Thyroid hormone replacement  • Once pregnant, increase thyroid hormone dose by approximately 30%
 •  Maintain the same TSH suppression goal in pregnancy as preconception for women with a history of DTC
 • Germline mutation of the RET oncogene with or without clinically apparent medullary thyroid cancer  • Refer to genetic counselor to discuss preconception, options of pre-implantation and/or prenatal genetic diagnostic testing
 •  If unwilling to undergo prenatal RET mutation testing, genetic counseling and genetic testing of the baby should be offered
 •  A pheochromocytoma should always be excluded in women with MEN2A or MEN2B
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SUMMARY.

Thyroid nodules and thyroid cancer affecting pregnancy, the post-partum period and preconception planning comprise of a unique and complex care paradigm. Current recommendations for diagnosis and management of thyroid nodules and cancer in pregnancy and post-partum mostly stem from retrospective cohort studies and case series, and even though we have some facts, many uncertainties still remain. These uncertainties make management of thyroid nodules and cancer in pregnancy, as well as preconception planning, challenging. Further prospective studies are needed to determine appropriate management strategies, while ensuring maternal and fetal well-being. Physicians should be supportive of a woman’s desire to conceive, and always factor her reproductive age span and excellent prognosis for most thyroid cancers when determining optimal timing for management and surveillance. Physician and patient shared decision-making should be guided by existing evidence, ascertainment of benefit-risk ratio and an interdisciplinary approach.

PRACTICE POINTS.

  • Fine needle aspiration (FNA) biopsy is safe and can be performed during any trimester in pregnancy

  • Suppressive doses of thyroid hormone should NOT be used to attempt to shrink thyroid nodules, in view of the risks of iatrogenic thyrotoxicosis

  • Use of molecular markers cannot currently be recommended for evaluation of indeterminate thyroid nodules in pregnancy

  • Neck ultrasounds should be performed each trimester in pregnant women with papillary microcarcinoma who are under active surveillance

  • Timing of surgery for pregnant women diagnosed with DTC (whether in the second trimester of pregnancy or post-partum) does not alter outcome

  • Use of radioactive iodine is absolutely contraindicated in pregnancy and during breastfeeding

  • It is reasonable to maintain the same degree of TSH suppression in pregnancy as preconception. Serum TSH should be checked every 4 weeks until 16-20 weeks of gestation, and subsequently at least once between weeks 26 and 32

  • Physicians should be supportive of pregnancy plans in women with a history of DTC and tailor management according to a woman’s age and desire to conceive

  • Genetic counseling should be offered to women of childbearing age with a germline mutation of the RET oncogene with or without clinically apparent medullary thyroid cancer, who are either trying to conceive or are pregnant

RESEARCH AGENDA.

  • Prospective studies evaluating the outcome and prognosis of pregnant women with indeterminate thyroid nodules are needed, including the effectiveness of molecular marker testing in these patients

  • Prospective studies to delineate whether pregnancy has an impact on the prognosis of newly diagnosed DTC, and whether it confers a higher risk of recurrence are needed

  • Studies to address the impact of pregnancy on progression of medullary or anaplastic thyroid carcinoma should be undertaken

  • Whether a thyroid cancer diagnosis changes plans for conception should be further investigated

  • Additional studies to further understand the impact of radioactive iodine on ovarian reserve should be pursued

ACKNOWLEDGEMENTS

Dr. Papaleontiou is funded by the National Institute on Aging of the National Institutes of Health (NIH) under Award Number K08 AG049684. Dr. Haymart is funded by R01 CA201198 from the National Cancer Institute and by R01 HS024512 from the Agency for Healthcare Research and Quality (AHRQ). The content is solely the responsibility of the authors and does not necessarily represent official views of the NIH or AHRQ. The authors would also like to acknowledge Ms. Brittany Gay who assisted with manuscript formatting and review.

Footnotes

CONFLICT OF INTEREST STATEMENT

The authors have nothing to disclose.

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Contributor Information

Maria Papaleontiou, Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan Health System, North Campus Research Complex, 2800 Plymouth Road, Bldg 16, Rm 453S, Ann Arbor, MI 48109.

Megan R. Haymart, Divisions of Metabolism, Endocrinology, and Diabetes and Hematology/Oncology, Department of Internal Medicine, University of Michigan Health System, North Campus Research Complex, 2800 Plymouth Rd., Bldg. 16, Rm 408E, Ann Arbor, MI 48109.

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