Disease severity and radioactive iodine use for thyroid cancer

Radioactive Iodine Therapy in Differentiated Thyroid Cancer: Summary of the Korean Thyroid Association Guidelines 2024 from Nuclear Medicine Perspective, Part-II

Thyroid cancer, one of the most common endocrine tumors, generally has a favorable prognosis but remains a significant medical and societal concern due to its high incidence. Early diagnosis and treatment of differentiated thyroid cancer (DTC) significantly affect long-term outcomes, requiring the selection and application of appropriate initial treatments to improve prognosis and quality of life. Recent advances in technology and health information systems have enhanced our understanding of the molecular genetics of thyroid cancer, facilitating the identification of aggressive subgroups and enabling the accumulation of research on risk factors through big data. The Korean Thyroid Association (KTA) has revised the "KTA Guidelines on the Management of Differentiated Thyroid Cancers 2024" to incorporate these advances, which were developed by a multidisciplinary team and underwent extensive review and approval processes by various academic societies. This article summarizes the 2024 KTA guidelines for radioactive iodine (RAI) therapy in patients with DTC, written by the Nuclear Medicine members of the KTA Guideline Committee, and covers RAI therapy as initial management of DTC and RAI therapy in advanced thyroid cancer.

Radioiodine therapy in the different stages of differentiated thyroid cancer

Differentiated thyroid cancer is the most frequent type of thyroid cancer with an increasing incidence in the last decades. The initial management is represented by surgical treatment followed by radioactive iodine therapy that includes remnant ablation, adjuvant treatment or treatment of metastatic disease. Radioactive iodine treatment is performed only in selected cases based on the risk of recurrence and mortality during follow up, according to American Joint Committee on Cancer Union for international Cancer Control Tumor, Node, Metastasis (AJCC/TNM) staging system and the 2015 American Thyroid Association (ATA) risk stratification system. This article will review the key factors to consider when planning radioactive iodine therapy in differentiated thyroid cancer patients after surgery and during follow up.

Patterns of radioiodine use for differentiated thyroid carcinoma in Brazil: insights and a call for action from a 20-year database

OBJECTIVE

This study aimed to explore the patterns of radioactive iodine (RAI) use for differentiated thyroid cancer (DTC) in Brazil over the past 20 years.

METHODS

A retrospective analysis of the DTC-related RAI prescriptions, from 2000 to 2018, retrieved from the Department of Informatics of the Unified Health System (Datasus) and National Supplementary Health Agency (ANS) database was performed. RAI activities prescriptions were re-classified as low (30-50 mCi), intermediate (100 mCi), or high activities (>100 mCi).

RESULTS

The number of DTC-related RAI prescriptions increased from 0.45 to 2.28/100,000 inhabitants from 2000 to 2015, declining onwards, closing 2018 at 1.87/100,000. In 2018, population-adjusted RAI prescriptions by state ranged from 0.07 to 4.74/100,000 inhabitants. Regarding RAI activities, in the 2000 to 2008 period, the proportion of high-activities among all RAI prescriptions increased from 51.2% to 74.1%. From 2009 onwards, there was a progressive reduction in high-activity prescriptions in the country, closing 2018 at 50.1%. In 2018, the practice of requesting high-activities varied from 16% to 82% between Brazilian states. Interestingly, variability of RAI use do not seem to be related to RAI referral center volume nor state socio-economic indicators.

CONCLUSION

In recent years, there has been a trend towards the lower prescription of RAI, and a reduction of high-activity RAI prescriptions for DTC in Brazil. Also, significative inter-state and inter-institutional variability on RAI use was documented. These results suggest that actions to advance DTC healthcare quality surveillance should be prioritized.

Ablation therapy using a low dose of radioiodine may be sufficient in low- to intermediate-risk patients with follicular variant papillary thyroid carcinoma

OBJECTIVES

Follicular variant papillary thyroid carcinoma (FVPTC) is treated similarly to classical variant papillary thyroid carcinoma (cPTC). However, FVPTC has unique tumour features and behaviours. We investigated whether a low dose of radioiodine was as effective as a high dose for remnant ablation in patients with FVPTC and evaluated the recurrence of low-intermediate risk FVPTC.

METHODS

Data from cPTC and FVPTC patients treated with I-131 from 2004 to 2014 were reviewed. Demographics, tumour behaviour, lymph node metastasis, and local recurrence data were compared between FVPTC and cPTC patients. Then, low-intermediate risk FVPTC patients were divided into low, intermediate, and high I-131 dose groups, and postoperative I-131 activities were analysed to evaluate the effectiveness of I-131 therapy for thyroid remnant ablation.

RESULTS

In total, 799 cases of FVPTC (n = 168) and cPTC (n = 631) treated with I-131 were identified. Patients with FVPTC had a larger primary nodule size than cPTC, but lymph node metastases and local recurrence were more prevalent in cPTC than in FVPTC. For the low-, intermediate-, and high-dose groups, success rates of ablation did not differ (82.0%, 80%, and 81.3%, respectively).

CONCLUSION

FVPTC differs from cPTC in behaviour. Low-dose ablation may be sufficient in FVPTC patients with low-intermediate disease risk.

Pros and cons of hemi-thyroidectomy for low-risk differentiated thyroid cancer

The debate regarding the surgical management of low-risk differentiated thyroid cancer (DTC) is ongoing. The recommended extent of surgery in DTC is based on an assessment of the predicted risk of recurrence and recent guidelines reflect an evolving philosophy of de-escalation of surgical management, informed by a growing understanding of the determinants of tumour biology and important prognostic factors. However, our current clinical and pathological risk stratification processes are imperfect and hence there is significant variation in clinical practice. Surgeons face the challenge of finding the balance between avoiding overtreatment, minimizing complications and providing adequate oncological management. This article discusses the nuances of the current management guidelines as well as the important considerations in preoperative decision making.

Physician Confidence in Neck Ultrasonography for Surveillance of Differentiated Thyroid Cancer Recurrence

IMPORTANCE

Neck ultrasonography, a mainstay of long-term surveillance for recurrence of differentiated thyroid cancer (DTC), is routinely used by endocrinologists, general surgeons, and otolaryngologists; however, physician confidence in their ability to use ultrasonography to identify lymph nodes suggestive of cancer recurrence remains unknown.

OBJECTIVE

To evaluate physicians' posttreatment surveillance practices for DTC recurrence, specifically their use of and confidence in ultrasonography.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study of 448 physicians in private and academic hospitals who completed a survey on DTC posttreatment practices from October 2018 to August 2019 (response rate, 69%) and self-reported involvement in long-term surveillance for thyroid cancer recurrence. Physicians were identified by patients affiliated with the Surveillance, Epidemiology, and End Results Program registries in Georgia State and Los Angeles County. Of the respondents, 320 physicians who reported involvement with DTC surveillance were included in the analysis.

MAIN OUTCOMES AND MEASURES

Physician-reported long-term surveillance practices for DTC, including frequency of use and level of confidence in ultrasonography for detecting lymph nodes suggestive of cancer recurrence.

RESULTS

In the cohort of 320 physicians who reported involvement with DTC surveillance, 186 (60%) had been in practice for 10 years to less than 30 years; 209 (68%) were White; and 212 (66%) were men. The physicians included 170 (56%) endocrinologists, 67 (21%) general surgeons, and 75 (23%) otolaryngologists. Just 84 (27%) physicians reported personally performing bedside ultrasonography. Only 57 (20%) had high confidence (rated quite or extremely confident) in their ability to use bedside ultrasonography to identify lymph nodes suggestive of recurrence; 94 (33%) did not report high confidence in either their ability or a radiologist's ability to use ultrasonography to detect recurrence. Higher confidence in ultrasonography was associated with the general surgery subspecialty (odds ratio [OR], 5.7; 95% CI, 2.2-14.4; reference endocrinology) and with treating a higher number of patients per year (>50 patients: OR, 14.4; 95% CI, 4.4-47.4; 31-50 patients: OR, 8.4; 95% CI, 2.6-26.7; 11-30 patients: OR, 4.3; 95% CI, 1.5-12.1; reference 0-10 patients).

CONCLUSIONS AND RELEVANCE

Given the importance of neck ultrasonography in long-term surveillance for thyroid cancer, these findings of physicians' low confidence in their own ability and that of radiologists to use ultrasonography to detect recurrence point to a major obstacle to standardizing long-term DTC surveillance practices.

Physician management of thyroid cancer patients' worry

PURPOSE

The purpose of this study is to understand physician management of thyroid cancer-related worry.

METHODS

Endocrinologists, general surgeons, and otolaryngologists identified by Surveillance, Epidemiology, and End Results (SEER) patients were surveyed 2018-2019 (response rate 69% (448/654)) and asked to rate in general their patients' worry at diagnosis and actions they take for worried patients. Multivariable-weighted logistic regressions were conducted to determine physician characteristics associated with reporting thyroid cancer as "good cancer" and with encouraging patients to seek help managing worry outside the physician-patient relationship.

RESULTS

Physicians reported their patients as quite/very worried (65%), somewhat worried (27%), and a little/not worried (8%) at diagnosis. Half of the physicians tell patients their thyroid cancer is a "good cancer." Otolaryngology (odds ratio (OR) 1.87, 95% confidence interval (CI) 1.08-3.21, versus endocrinology), private practice (OR 2.48, 95% CI 1.32-4.68, versus academic setting), and Los Angeles (OR 2.24, 95% CI 1.45-3.46, versus Georgia) were associated with using "good cancer." If patients are worried, 97% of physicians make themselves available for discussion, 44% refer to educational websites, 18% encourage communication with family/friends, 13% refer to support groups, and 7% refer to counselors. Physicians who perceived patients being quite/very worried were less likely to use "good cancer" (OR 0.54, 95% CI 0.35-0.84) and more likely to encourage patients to seek help outside the physician-patient relationship (OR 1.82, 95% CI 1.17-2.82).

IMPLICATIONS FOR CANCER SURVIVORS

Physicians perceive patient worry as common and address it with various approaches, with some approaches of unclear benefit. Efforts are needed to develop tailored interventions targeting survivors' psychosocial needs.

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.

Factors Associated With Diagnosis and Treatment of Thyroid Microcarcinomas

CONTEXT

Nearly one-third of all thyroid cancers are ≤1 cm.

OBJECTIVE

To determine diagnostic pathways for microcarcinomas vs larger cancers.

DESIGN/SETTING/PARTICIPANTS

Patients from Georgia and Los Angeles Surveillance, Epidemiology, and End Results (SEER) registries with differentiated thyroid cancer diagnosed in 2014 or 2015 were surveyed. Survey data were linked to SEER data on tumor and treatment characteristics. Multivariable logistic regression analysis was performed.

MAIN OUTCOME MEASURES

Method of nodule discovery; reason for thyroid surgery.

RESULTS

Of patients who underwent surgery, 975 (38.2%) had cancers ≤1 cm, and 1588 cancers (61.8%) were >1 cm. The reported method of nodule discovery differed significantly between patients with cancers ≤1 cm and those with cancers >1 cm (P < 0.001). Cancer ≤1 cm was associated with nodule discovery on thyroid ultrasound (compared with other imaging, OR, 1.59; 95% CI, 1.21 to 2.10), older patient age (45 to 54 years vs ≤44, OR, 1.45; 95% CI, 1.16 to 1.82), and female sex (OR, 1.51; 95% CI, 1.22 to 1.87). Hispanic ethnicity (OR, 0.71; 95% CI, 0.57 to 0.89) and Asian race (OR, 0.67; 95% CI, 0.49 to 0.92) were negative correlates. Cancers ≤1 cm were associated with lower likelihood of surgery for a nodule suspicious or consistent with cancer (OR, 0.48; 95% CI, 0.40 to 0.57).

CONCLUSION

Thyroid microcarcinomas are more likely to be detected by ultrasound and less likely to be associated with surgery scheduled for known thyroid cancer. Understanding diagnostic pathways allows for targeted interventions to decrease overdiagnosis and overtreatment.

Contemporary Debates in Adult Papillary Thyroid Cancer Management

An ever-increasing population of patients with papillary thyroid cancer is engaging with health care systems around the world. Numerous questions about optimal management have arisen that challenge conventional paradigms. This is particularly the case for patients with low-risk disease, who comprise most new patients. At the same time, new therapies for patients with advanced disease are also being introduced, which may have the potential to prolong life. This review discusses selected controversial issues in adult papillary thyroid cancer management at both ends of the disease spectrum. These topics include: (i) the role of active surveillance for small papillary cancers; (ii) the extent of surgery in low-risk disease (lobectomy vs total thyroidectomy); (iii) the role of postoperative remnant ablation with radioiodine; (iv) optimal follow-up strategies in patients, especially those who have only undergone lobectomy; and (v) new therapies for advanced disease. Although our current management is hampered by the lack of large randomized controlled trials, we are fortunate that data from ongoing trials will be available within the next few years. This information should provide additional evidence that will decrease morbidity in low-risk patients and improve outcomes in those with distant metastatic disease.

Too Much of a Good Thing: Radioactive Iodine Ablation Use for Micropapillary Thyroid Carcinoma

Radioactive iodine (RAI) is not routinely recommended for the adjuvant treatment of micro-papillary thyroid carcinoma (MPTC). We aimed to report on clinical and pathologic factors associated with the use of RAI in these patients. We queried the Surveillance, Epidemiology, and End Results database for patients who underwent surgery for MPTC (tumor size ≤1 cm) from 1988 to 2009. We excluded patients without a biopsy-proven diagnosis, those diagnosed at autopsy, and patients with documented extra-thyroidal extension. Multivariate logistic regression models predicted the use of RAI based on patient, tumor, and treatment-related factors. We identified 24,076 patients with MPTC that were eligible for study inclusion. Of these, 6,172 (25.6%) received RAI. Lymph node metastases were present in 23.8 per cent of those for whom lymph node status was known. On multivariate analysis, an increasing number of positive nodes, increasing tumor size, Asian race, and male gender predicted the use of RAI. RAI use was less likely in those with advancing age, an increasing number of lymph nodes examined and patients that received less than a total thyroidectomy. Among node-negative patients, Asian race and increasing tumor size predicted the use of RAI. Factors predicting decreased use of RAI were an increasing number of lymph nodes examined, unknown race, less than a total thyroidectomy, and advancing age. A significant number of MPTC patients receive potentially unnecessary RAI.

Effects of socioeconomic status on children with well-differentiated thyroid cancer

BACKGROUND

Well-differentiated thyroid cancer is the most common endocrine malignancy in children. Adult literature has demonstrated socioeconomic disparities in patients undergoing thyroidectomy, but the effects of socioeconomic status on the management of pediatric well-differentiated thyroid cancer remains poorly understood.

METHODS

Patients ≤21 years of age with well-differentiated thyroid cancer remains were reviewed from the National Cancer Data Base. Three socioeconomic surrogate variables were identified: insurance type, median income, and educational quartile. Tumor characteristics, diagnostic intervals, and clinical outcomes were compared within each socioeconomic surrogate variable.

RESULTS

A total of 9,585 children with well-differentiated thyroid cancer remains were reviewed. In multivariate analysis, lower income, lower educational quartile, and insurance status were associated with higher stage at diagnosis. Furthermore, lower income quartile was associated with a longer time from diagnosis to treatment (P < .002). Similarly, uninsured children had a longer time from diagnosis to treatment (28 days) compared with those with government (19 days) or private (18 days) insurance (P < .001). Despite being diagnosed at a higher stage and having a longer time interval between diagnosis and treatment, there was no significant difference in either overall survival or rates of unplanned readmissions based on any of the socioeconomic surrogate variables.

CONCLUSION

Children from lower income families and those lacking insurance experienced a longer period from diagnosis to treatment of their well-differentiated thyroid cancer remains. These patients also presented with higher stage disease. These data suggest a delay in care for children from low-income families. Although these findings did not translate into worse outcomes for well-differentiated thyroid cancer remains, future efforts should focus on reducing these differences.

REFERRAL OF OLDER THYROID CANCER PATIENTS TO A HIGH-VOLUME SURGEON: RESULTS OF A MULTIDISCIPLINARY PHYSICIAN SURVEY

OBJECTIVE

Surgical outcomes of thyroid cancer patients are improved with high-volume surgeons. However, age disparities in referral to specialist surgical centers still exist. The factors that influence decision making regarding referral of older thyroid cancer patients to high-volume surgeons remain unknown.

METHODS

We surveyed members of the Endocrine Society, American College of Physicians, and American Academy of Family Practice.

RESULTS

Overall, 270 physicians completed the survey. Patient preference (69%), transportation barriers (62%), and confidence in local surgeon (54%) were the most cited factors decreasing likelihood of referral to a high-volume surgeon. In clinical scenarios, referral rates to a high-volume surgeon were similar for patients aged 40 and 65 years with a 1-cm thyroid nodule diagnostic of thyroid cancer (n = 137 [54%]; n = 132 [52%], respectively) as for an 85-year-old with a 4-cm nodule (n = 148 [59%]). When comorbidities were introduced, more physicians (n = 186 [74%]) would refer a 65-year-old with a 4-cm thyroid nodule and comorbidities, compared to an 85-year-old with the same nodule size without comorbidi-ties. In multivariable analysis, treating >10 thyroid cancer patients/year (P<.001; P<.005) and endocrinology specialty (P = .003; P = .003) were associated with referral to a high-volume surgeon for a 65-year-old with comorbidities and an 85-year-old without comorbidities, respectively.

CONCLUSION

Understanding surgical referral patterns of older thyroid cancer patients is vital in identifying obstacles in the referral process. We found that patient factors including comorbidities and physician factors including specialty and patient volume influence these patterns. This is the first step towards developing targeted interventions for these patients.

Selective use of radioactive iodine (RAI) in thyroid cancer: No longer "one size fits all"

A remarkable, evidence-based trend toward de-escalation has reformed the practice of radioactive iodine (RAI) administration for thyroid cancer patients. Updated guidelines have supported both decreased RAI doses for select populations, as well as expanded definitions of low-risk and intermediate-risk patients that may not require RAI. Correspondingly, there is now increased flexibility for hemithyroidectomy without need for RAI, and relaxed TSH suppression targets for low-risk thyroidectomy patients. Clinical judgment remains indispensable where multiple risk factors co-exist that individually are not indications for RAI. This is especially salient in intermediate-risk patients with a less than excellent response to therapy, determined through thyroglobulin and ultrasound surveillance. Such judgment, however, may lead to patterns of inappropriate RAI practices or overuse with little benefit to the patient and unnecessary harm. A multidisciplinary, risk-adapted approach is ever more important and obliges the surgeon to understand the likelihood that their patients will receive RAI. The risks and benefits of RAI, its evolved role in contemporary guidelines, and current patterns of use among endocrinologists are reviewed, as well as the practical implications for thyroid surgeons.

Regional Variation across Canadian Centers in Radioiodine Administration for Thyroid Remnant Ablation in Well-Differentiated Thyroid Cancer Diagnosed in 2000-2010

Background. Use of radioactive iodine (RAI) ablation has been reported to vary significantly between studies. We explored variation in RAI ablation care patterns between seven thyroid cancer treatment centers in Canada. Methods. The Canadian Collaborative Network for Cancer of the Thyroid (CANNECT) is a collaborative registry to describe and analyze patterns of care for thyroid cancer. We analyzed data from seven participating centers on RAI ablation in patients diagnosed with well-differentiated (papillary and follicular) thyroid cancer between 2000 and 2010. We compared RAI ablation protocols including indications (based on TNM staging), preparation protocols, and administered dose. We excluded patients with known distant metastases at time of RAI ablation. Results. We included 3072 patients. There were no significant differences in TNM stage over time. RAI use increased in earlier years and then declined. The fraction of patients receiving RAI varied significantly between centers, ranging between 20–85% for T1, 44–100% for T2, 58–100% for T3, and 59–100% for T4. There were significant differences in the RAI doses between centers. Finally, there was major variation in the use of thyroid hormone withdrawal or rhTSH for preparation of RAI ablation. Conclusion. Our study identified significant variation in use of RAI for ablation in patients with well-differentiated thyroid cancer both between Canadian centers and over time.

Practice patterns among thyroid cancer surgeons: implications of performing a prophylactic central neck dissection

Background

Indications for performing a prophylactic central neck dissection (pCND) in papillary thyroid cancer (PTC) remain controversial. It is unclear how identification of lymph node (LN) metastases should impact the decision to treat with radioactive iodine (RAI). The goals of this study were to identify indications for performing pCND and identify factors that predict the use of adjuvant RAI.

Methods

This was a population based cross-sectional analysis. A prospectively collected database identified 594 patients who underwent total thyroidectomy +/− CND. A multivariate model was constructed to identify indications for pCND and predictors of the use of RAI.

Results

425 CNDs were performed of which 224 were prophylactic. Conventional risk factors (age, tumor size, extra-thyroidal extension) were not associated with performing a pCND. The presence of clinically suspicious lymphadenopathy was the only factor associated with performing CND, thus rendering the CND therapeutic. Positive LNs were retrieved in 39 % of pCND’s, upstaging 87 patients. Among all peri-operative predictors of receiving RAI, presence of LN metastases was the strongest predictor [OR = 5.9 (3.7–9.5)], while tumor size was a modest predictor [OR = 1.8 (1.5–2.1)]. Other conventional risk factors did not predict use of adjuvant RAI.

Conclusions

Conventional risk factors were not indications for performing a pCND, implying that the decision was based on individual surgeon preference. Performing pCND upstaged 39 % of patients from cN0 to pN1a, increasing the likelihood of receiving RAI 6-fold. Conventional risk factors were not predictors of receiving adjuvant RAI. This highlights the need for a unified approach to performing a pCND and administering RAI.

Comparison of radioiodine utilization in adolescent and young adult and older thyroid cancer patients

OBJECTIVE

Differentiated thyroid cancer (DTC) is 1 of the most common cancers in adolescents and young adults (AYA, ages 15-39). Although most AYAs with DTC are considered low risk compared to older patients, there are no specific postoperative radioiodine (RAI) treatment recommendations despite the potential adverse effects specific to this age group, namely secondary malignancies and fertility difficulties. This study compares factors influencing RAI utilization in AYA and older patients.

METHODS

A total of 5,687 primary DTC patients were identified from the SEER (Surveillance, Epidemiology, and End RESULTS) database between January 1, 2004 and January 31, 2009. The 2009 American Thyroid Association (ATA) guidelines were used to classify patients as low (LR) or intermediate/high risk (IHR) based on tumor characteristics. Multivariate logistic regression analysis was performed.

RESULTS

Overall, 56.9% of AYA (n = 1,963) patients received postoperative RAI compared to 52.2% of older (n = 3,724) patients (odds ratio [OR]: 1.21, 95% confidence interval [CI]: 1.09-1.35, P = .001). For AYA patients, having a total thyroidectomy (TTx) (OR: 3.53, 95% CI: 2.7-4.61, P<.001) predicted RAI in a multivariate model whereas LR status (OR: 0.52, 95% CI: 0.43-0.63, P<.001) and northeast residence (OR: 0.39, 95% CI: 0.29-0.52, P<.001) decreased the probability. All 3 factors similarly affected older patients in addition to an increased likelihood after lymph node (LN) dissection. Additionally, after selecting for TTx (n = 1,077), no factor influenced the use of RAI for AYA patients, whereas LR (OR: 0.30, 95% CI: 0.21-0.43, P<.001) and northeast residence (OR: 0.39, 95% CI: 0.19-0.79, P = .008) were associated with decreased RAI use in older patients.

CONCLUSION

Despite their excellent prognosis, AYA thyroid cancer patients are more likely to receive postoperative RAI compared to older patients. Increased awareness of the unique survivorship implications for AYA patients will be an important aspect to address going forward.

TIMING OF RADIOACTIVE IODINE THERAPY DOES NOT IMPACT OVERALL SURVIVAL IN HIGH-RISK PAPILLARY THYROID CARCINOMA

OBJECTIVE

Postthyroidectomy radioiodine (RAI) therapy is indicated for papillary thyroid carcinoma (PTC) with high-risk features. There is variability in the timing of RAI therapy with no consensus. We analyzed the impact of the timing of initial RAI therapy on overall survival (OS) in PTC.

METHODS

The National Cancer Data Base (NCDB) was queried from 2003 to 2006 for patients with PTC undergoing near/subtotal or total thyroidectomy and RAI therapy. High-risk patients had tumors >4 cm in size, lymph node involvement, or grossly positive margins. Early RAI was ≤3 months, whereas delayed was between 3 and 12 months after thyroidectomy. Kaplan-Meier (KM) and Cox survival analyses were performed after adjusting for patient and tumor-related variables. A propensity-matched set of high-risk patients after eliminating bias in RAI timing was also analyzed.

RESULTS

There were 9,706 patients in the high-risk group. The median survival was 74.7 months. KM analysis showed a survival benefit for early RAI in high-risk patients (P = .025). However, this difference disappeared (hazard ratio [HR] 1.26, 95% confidence interval [CI] 0.98-1.62, P = .07) on adjusted Cox multivariable analysis. Timing of RAI therapy failed to affect OS in propensity-matched high-risk patients (HR 1.09, 95% CI 0.75-1.58, P = .662).

CONCLUSION

The timing of postthyroidectomy initial RAI therapy does not affect OS in patients with high-risk PTC.

ABBREVIATIONS

CI = confidence interval CLNM = cervical lymph node metastasis FVPTC = follicular variant papillary thyroid carcinoma HR = hazard ratio KM = Kaplan-Meier NCDB = National Cancer Data Base OS = overall survival PTC = papillary thyroid carcinoma RAI = radioactive iodine.

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.

Same thyroid cancer, different national practice guidelines: When discordant American Thyroid Association and National Comprehensive Cancer Network surgery recommendations are associated with compromised patient outcome

BACKGROUND

The American Thyroid Association (ATA) and National Comprehensive Cancer Network (NCCN) guidelines have discordant recommendations for managing patients with differentiated thyroid cancer (DTC). We hypothesized that physician adherence to either of the 2009 extent of surgery guidelines of the ATA or NCCN was associated with improved survival, and that practice is most standardized nationally when guidelines are concordant.

METHODS

Adult patients undergoing surgery for DTC were included from the National Cancer Database. Multivariable modeling was used to identify factors associated with nonadherence to the 2009 ATA or NCCN guidelines (2010-2011) and hypothetically examine the association of retrospective adherence to guidelines with survival (1998-2006).

RESULTS

A total of 39,687 patients with DTC were included; 2,249 were not treated in accordance with ATA or NCCN guidelines. Factors independently associated with nonadherence were discordance between ATA and NCCN recommendations, black race, and treatment at nonacademic centers (P < .01). After adjustment, care not in accordance with either set of guidelines was associated with compromised survival (hazard ratio 1.16, P = .02).

CONCLUSION

A minority of patients received surgery for DTC not aligned with guidelines; nonadherent care was associated with compromised survival. Discordance in recommendations between guidelines is associated with reduction in adherent care, suggesting that standardizing guidelines could decrease confusion, increase adherence, and thereby may improve outcomes.

Long-Term Outcomes Following Therapy in Differentiated Thyroid Carcinoma: NTCTCS Registry Analysis 1987-2012

CONTEXT

Initial treatments for patients with differentiated thyroid cancer are supported primarily by single-institution, retrospective studies, with limited follow-up and low event rates. We report updated analyses of long-term outcomes after treatment in patients with differentiated thyroid cancer.

OBJECTIVE

The objective was to examine effects of initial therapies on outcomes.

DESIGN/SETTING

This was a prospective multi-institutional registry.

PATIENTS

A total of 4941 patients, median follow-up, 6 years, participated.

INTERVENTION

Interventions included total/near-total thyroidectomy (T/NTT), postoperative radioiodine (RAI), and thyroid hormone suppression therapy (THST).

MAIN OUTCOME MEASURE

Main outcome measures were overall survival (OS) and disease-free survival using product limit and proportional hazards analyses.

RESULTS

Improved OS was noted in NTCTCS stage III patients who received RAI (risk ratio [RR], 0.66; P = .04) and stage IV patients who received both T/NTT and RAI (RR, 0.66 and 0.70; combined P = .049). In all stages, moderate THST (TSH maintained subnormal-normal) was associated with significantly improved OS (RR stages I-IV: 0.13, 0.09, 0.13, 0.33) and disease-free survival (RR stages I-III: 0.52, 0.40, 0.18); no additional survival benefit was achieved with more aggressive THST (TSH maintained undetectable-subnormal). This remained true, even when distant metastatic disease was diagnosed during follow-up. Lower initial stage and moderate THST were independent predictors of improved OS during follow-up years 1-3.

CONCLUSIONS

We confirm previous findings that T/NTT followed by RAI is associated with benefit in high-risk patients, but not in low-risk patients. In contrast with earlier reports, moderate THST is associated with better outcomes across all stages, and aggressive THST may not be warranted even in patients diagnosed with distant metastatic disease during follow-up. Moderate THST continued at least 3 years after diagnosis may be indicated in high-risk patients.

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 impact of socioeconomic status on the use of adjuvant radioactive iodine for papillary thyroid cancer

INTRODUCTION

The effect of socioeconomic status (SES) on thyroid cancer treatment has not been studied extensively. The purpose of this study is to determine the impact of SES on the use of adjuvant radioactive iodine (RAI) after total thyroidectomy for papillary thyroid cancer (PTC). We hypothesize that patients of low SES are less likely to receive RAI after total thyroidectomy.

METHODS

Case characteristics of 9011 patients with PTC ≥ 1 cm in size and undergoing total thyroidectomy were extrapolated from the Surveillance, Epidemiology and End Results database. Chi-square test and multivariate analyses were performed to compare demographics, clinicopathologic features, and use of RAI by county-level measures of SES.

RESULTS

Low-SES patients were more likely to present with positive lymph nodes in the <45-year age group and with advanced American Joint Committee on Cancer stage, positive lymph nodes, multifocal tumors, extrathyroidal extension, and larger tumors in the ≥ 45-year age group. Among patients <45 years of age, those from counties with a higher median household income and a higher SES composite score had significantly higher rates of RAI use (odds ratio [OR] 1.36, [95% confidence interval (CI) 1.09-1.70], p=0.006, and OR 1.29 [CI 1.11-1.49], p<0.001, respectively). Among patients ≥ 45 years of age, those residing in counties with higher education levels were associated with higher rates of RAI use (OR 1.27 [CI 1.05-1.54], p=0.015), while the association between SES composite score and RAI use approached statistical significance (OR 1.13 [CI 1.00-1.28], p=0.053).

CONCLUSIONS

This study demonstrates that low SES is associated with more advanced PTC at presentation and a lower rate of adjuvant RAI after total thyroidectomy, particularly among patients <45 years of age from areas with a low median household income. Future studies are needed to address these disparities, as well as to determine appropriate indications for the use of adjuvant RAI for PTC.

Impact of early vs late postoperative radioiodine remnant ablation on final outcome in patients with low-risk well-differentiated thyroid cancer

OBJECTIVE

Postoperative radioiodine remnant ablation (RRA) represents an adjunctive therapeutic modality in patients with differentiated thyroid cancer (DTC). The impact of late vs early RRA on the outcome of DTC is currently unclear. The aim of the study was to evaluate the outcome of patients with DTC according to RRA timing.

DESIGN RETROSPECTIVE STUDY PATIENTS

A total of 107 TNM stage 1 DTC patients were divided into two groups. In group A (n = 50), RRA was administered in less than 4·7 months median 3·0 (range 0·8-4·7), while in group B (n = 57) in more than 4·7 months median 6 (4·8-30·3) after thyroidectomy. Remission was achieved when stimulated serum Tg levels were undetectable, in the absence of local recurrence or cervical lymph node metastases on the neck ultrasound.

RESULTS

All patients underwent near-total thyroidectomy. The mean age at diagnosis was 49·3 years (range: 18-79 years). There were no statistically significant differences in the histological subtype, the TNM stage, the dose of radioiodine and the time of follow-up, between the two groups. After the RRA treatment, 44 group A patients (88%) were in remission and 6 (12%) in persistence; while in group B, 52 (91·2%) were in remission, 1 (1·8%) in persistence and 4 (7%) in recurrence. At their latest follow-up median 87·3 (23·3-251·6 months), all patients were in remission, either as a result of further iodine radioiodine therapy (in 11 patients) or watchful monitoring.

CONCLUSIONS

The timing of RRA seems to have no effect on the long-term outcome of the disease. Therefore, urgency for radioiodine ablation in patients with low-risk thyroid cancer is not recommended.

Differentiated thyroid carcinoma: defining new paradigms for postoperative management

The demography of differentiated thyroid cancers (DTCs) has changed considerably since the 1990s, when the vast majority of these tumors were clinically evident at the time of diagnosis, and many were associated with regional lymph node involvement. Today's DTCs are more likely to be small, localized, asymptomatic papillary forms that are discovered incidentally, during neck imaging procedure performed for other reasons or during postoperative assessment of a gland removed for benign nodular goiter. The tools available for diagnosing, treating, and monitoring DTCs have also changed and their diagnostic capacities have increased. For these reasons, DTC treatment and follow-up paradigms are being revised to ensure more appropriate, cost-effective management of the current generation of DTCs. This review examines some of the key issues in this area, including the assessment of risks for disease recurrence and thyroid cancer-related death, the indications for postoperative ablation of the thyroid remnant with radioactive iodine and TSH-suppressive doses of levothyroxine, the pros, cons, and rationales for the use of various follow-up tools (serum thyroglobulin assays, neck ultrasound, 2-[18F]fluoro-2-deoxyglucose-positron emission tomography, and whole-body (131)I scintigraphy), and temporal strategies for maximizing their efficacy. An algorithm is presented for individualized, risk-tailored management of DTC patients.