Rising incidence of second cancers in patients with low-risk (T1N0) thyroid cancer who receive radioactive iodine therapy

Association between postoperative radiotherapy for young-onset nonsmall cell lung cancer and risk of second primary malignancies: comparative study

BACKGROUND

The most common form of therapy for nonsmall cell lung cancer (NSCLC) in early stage is surgery-based combination therapy, including radiotherapy and immunotherapy. However, postoperative radiotherapy (PORT) of cancer is correlated with increasing risk of second primary malignancy (SPM), especially young-onset cancer cases. The authors aimed to quantify the risks of SPM associated with PORT treatment for young‑onset NSCLC in early stage.

METHODS

The authors screened for SPM that developed over 5 years since the diagnosis of NSCLC. Using the data from the Surveillance, Epidemiology, and End Results database, PORT-correlated risks were estimated with multivariate Logistic regression analysis. Moreover, Fine-Gray's competing risk regression analysis was used to calculate the cumulative incidence of SPMs.

RESULTS

Among the 30 308 young-onset NSCLC patients in early stage undergoing surgery, a total of 3728 patients have received PORT. Logistic regression analyses showed that PORT showed substantial correlation with elevated risks of second solid malignancies [relative risks (RR)=1.31; 95% CI: 1.17-1.46], lung cancer (RR=1.23; 95% CI: 1.07-1.42), breast cancer (RR=1.74; 95% CI: 1.16-2.74), and colon and rectum cancers (RR=1.37; 95% CI: 1.07-2.06) as well as a negligible risk of second hematologic malignancies (RR=1.15; 95% CI: 0.82-1.67). The cumulative incidence of SPMs revealed similar findings. Higher RR was obtained in NSCLC patients aged 60-69 years (RR=1.33), in white race (RR=1.36), diagnosed in 1975-2000 (RR=1.23) and 2001-2015 (RR=1.40), or diagnosed with lung adenocarcinoma (RR=1.55).

CONCLUSION

PORT for young-onset NSCLC in early stage was correlated with elevated risks of SPMs (lung cancer, breast cancer, as well as colon and rectum cancers), supporting the need for long-term surveillance of these patients.

Radioactive Iodine Therapy in Differentiated Thyroid Cancer: An Update on Dose Recommendations and Risk of Secondary Primary Malignancies

Radioactive iodine (RAI) therapy with iodine-131 is performed in select cases of differentiated thyroid cancer (DTC), typically for remnant ablation, adjuvant therapy, or treatment of known persistent disease. Herein, we review updated RAI dose recommendations and associated risks of secondary primary malignancy (SPM). RAI dose is usually chosen empirically based on the risk assessment of tumor recurrence and other factors. Dose recommendations differ slightly among relevant medical societies. As of April 2024, most medical societies, including the American Thyroid Association (ATA), European Thyroid Association (ETA), Society of Nuclear Medicine and Molecular Imaging/European Association of Nuclear Medicine (SNMMI/ EANM), and National Comprehensive Cancer Network (NCCN), recommend a dose of 1.11 GBq (30 mCi) I-131 for remnant ablation. For adjuvant therapy, the recommended RAI dose ranges from 1.11 to 3.7 GBq (30-100) mCi I-131, although doses up to 5.6 GBq (150 mCi) may also be considered. In patients with known or suspected metastatic disease, at least 3.7 GBq (100 mCi) I-131 should be administered, and RAI doses as high as 7.4 GBq (200 mCi) may be justified depending on the suspected tumor burden and extent. Dosimetry has the advantage of tailoring the RAI dose to each patient's pharmacokinetics, resulting in ≥ 7.4 GBq (200 mCi) of I-131 in most cases. There is an ongoing debate about the risk of developing SPM due to RAI therapy, with several multicenter studies and meta-analyses concerning SPM being published in the last 2 years. The incidence of RAI-associated SPM varies according to the study design and detection method. Several studies showed no increased incidence, and there was no specific secondary cancer or cancer group linked to RAI exposures. Some reports indicated that cumulative RAI doses exceeding 5.6-7.4 GBq (150-200 mCi) were found to represent an increased risk for developing SPM. However, a clearly defined dose threshold cannot be provided based on the current literature. Nonetheless, caution should be exercised when considering repeated RAI therapies for persistent metastatic PTC, with a cumulative dose exceeding 37.0 GBq (1,000 mCi), due to the potential risk of developing SPM and other long-term toxicity. Further research is warranted to understand better the relationship between RAI dose and the risk of SPM.

Current approach to pediatric differentiated thyroid cancer

Differentiated thyroid cancers (DTC) is a rare cancer in children and adolescents, having features of different clinical presentation, biological behavior, and treatment from adult population. Most of the patient management guidelines are based on literature on adult population and the literature on children and adolescents still limited. There are still unsettled issues regarding both patient management and the therapy. However, the current approach for treatment of DTC includes thyroidectomy, lymph node dissection in patients with nodal metastases and possible use of Iodine-131 radiotherapy. The incidence of DTC is low in pediatric population, and the characteristics of the disease vary among different age groups within this population. Therefore, the literature depends on small cohorts and heterogeneous retrospective studies. This paper aims to review the current literature and give an overview to the approach in the management of DTC in pediatric population. DTC in pediatric population, has an aggressive nature, however the patient's overall survival is excellent. A multidisciplinary approach in the management of pediatric DTC patients would yield fewer side effects and a better life quality.

Absorbed dose coefficients for pediatric differentiated thyroid cancer patients undergoing radioiodine therapy

The escalating incidence of differentiated thyroid cancer (DTC) in pediatric patients and the resultant growing use of radioactive iodine (RAI) reinforce the need to evaluate radiation exposure to normal tissues and radiation-induced health risks in pediatric patients undergoing RAI therapy. In the current study, we calculated absorbed dose coefficients (i.e. absorbed dose per unit activity administered, mGy MBq-1) specific for pediatric patients with localized DTC undergoing RAI therapy following total thyroidectomy for use in epidemiological studies. We first modified previously-published biokinetic models for adult thyroid cancer patients to achieve a reasonable agreement with iodine biokinetics observed in pediatric patients or design principles addressed in the International Commission on Radiological Protection (ICRP) reference age-specific biokinetic models. We then combined the biokinetic models in conjunction withSvalues derived from ICRP reference pediatric voxel phantoms. The absorbed dose coefficients for pediatric patients were overall greater than those for adults with a ratio (pediatric/adult) up to 11.6 and rapidly decreased with increasing age. The sensitivity analysis showed that the renal clearance rate andSvalues may have the greatest impact on the absorbed dose coefficients with the rank correlation coefficients ranging from -0.53 to -0.82 (negative correlations) and from 0.51 to 0.80 (positive correlations), respectively. The results of the current study may be utilized in clinical or epidemiological studies to estimate organ-specific radiation absorbed doses and radiation-associated health risks among pediatric thyroid cancer patients.

Impact of thyroid hormone replacement on the risk of second cancer after thyroidectomy: a Korean National Cohort Study

We aimed to investigate the effect of thyroid hormone administration on the risk of second primary cancer in patients who underwent thyroidectomy for differentiated thyroid cancer. Data were extracted from the medical billing data of the Health Insurance Review and Assessment Service in South Korea. Patients between 19 and 80 years old who underwent thyroid surgery at least once between January 2009 and June 2020 were included. Data of patients with second primary cancer and control patients with matched age, sex, operation date, and follow-up duration were extracted at a ratio of 1:4. A nested case-control analysis was performed to exclude length bias to confirm the correlation between the duration of thyroid hormone administration, dose, and incidence of second primary cancer. Of the 261,598 patients who underwent surgery for thyroid cancer included in the study, 11,790 with second primary cancer and 47,160 without second primary cancer were matched. The average dose of thyroid hormone increased the adjusted odds ratio (OR) for both low (≤ 50 μg, OR 1.29, confidence interval (CI) 1.12-1.48) and high (< 100 μg, OR 1.24, CI 1.12-1.37) doses. Analyzing over time, the adjusted OR of second primary cancer increased, especially in short (≤ 1 year) (OR 1.19; CI 1.06-1.34) and long (> 5 years) duration (OR 1.25; CI 1.10-1.41). In conclusion, insufficient and excessive thyroid hormone replacement might be linked to increased second primary cancer in patients who underwent thyroidectomy for differentiated thyroid cancer.

Short-Term Complications After Total Thyroidectomy in Children

INTRODUCTION

Total thyroidectomy for benign disease is becoming more common among children. The purpose of this study was to evaluate 30-day outcomes in children undergoing total thyroidectomy and determine if the short-term outcomes are different in those with a malignant versus benign indication for surgery.

METHODS

This retrospective cohort study used the American College of Surgeons National Surgical Quality Improvement Program-Pediatric (NSQIP-Pediatric) to identify all children who underwent total thyroidectomy from 2015 to 2019. Fisher's exact test was used to compare postoperative outcomes between benign and malignant indications for thyroidectomy.

RESULTS

Among 1595 total thyroidectomy patients, 1091 (68.4%) had a benign indication and 504 (31.6%) had a malignant indication. There were 1234 (77.4%) females, and the median age was 14.9 y (interquartile range [IQR] 12.5, 16.6). Average length of stay (LOS) was similar between cohorts (1.7 d for benign and 1.9 d for malignant, P = 0.30). Parathyroid auto-transplantation was performed in 71 (6.5%) patients in the benign cohort and 43 (8.6%) in the malignant cohort (P = 0.15). The most common complications were readmissions (23 [2.1%] benign and 15 [3.0%] malignant, P = 0.29) and reoperations (7 [0.6%] benign and 5 [1.0%] malignant, P = 0.54). Complication profiles were similar between benign and malignant cohorts (2.8% and 4.6%, respectively [P = 0.10]).

CONCLUSIONS

Children undergoing total thyroidectomy for benign and malignant indications have low rates of 30-d postoperative complications, suggesting that total thyroidectomy is a safe option for children with benign disease. Evaluation of long-term outcomes is needed.

Response to Surgery Assessments for Sparing Radioiodine Remnant Ablation in Intermediate-risk Papillary Thyroid Cancer

CONTEXT

Using response to surgery upon tailoring radioiodine (RAI) therapy for papillary thyroid cancer (PTC) is valued while lacking prospective validation.

OBJECTIVE

To spare RAI thyroid-remnant ablation among intermediate-risk PTCs by three-tiered assessments with response to surgery highlighted besides the risk of the recurrence stratification and TNM staging.

DESIGN, SETTING AND PARTICIPANTS

Patients with no evidence of disease (NED) identified as excellent response (ER) or indeterminate response (IDR) to surgery were spared from RAI thyroid-remnant ablation after informed consent and prospectively enrolled under active surveillance. Those involved in other trials or without sufficient follow-up data were excluded. Dynamic responses were followed and compared longitudinally.

MAIN OUTCOME MEASURES

NED presenting as durable ER or IDR for over 12 months.

RESULTS

Of the enrolled 215 patients, 47.4% (102/215) ER and 52.6% (113/215) IDR were identified upon RAI decision-making. After a median of 23.6 (IQR 13.8-31.6) months, the share of ER increased to 82.8%(178/215) and IDR decreased to 16.3% (35/215), with 85 patients shifting from IDR to ER over time, only 0.5% (1/215) structural and 0.5% (1/215) biochemical incomplete response observed. Successful remnant ablation was observed in 27.7%(26/94) of the patients completing two diagnostic whole-body scannings after a median interval of 13.0 months, indicating a theranostic effect. In the 173 patients followed for over 12 months, the NED rate didn't differ between ER and IDR subgroups (100% vs. 97.9%, P = 0.20).

CONCLUSIONS

Through the three-tiered assessments with response to surgery highlighted, postoperative ER and IDR spared from RAI remnant ablation may indicate similar favorable responses in intermediate-risk PTC patients during 23.6 months follow-up.

Second Primary Malignancies in Patients with Differentiated Thyroid Cancer after Radionuclide Therapy: A Retrospective Single-Centre Study

Second primary malignancies (SPM) are described as any primary, not synchronous, malignancy arising in a different anatomical district, with confirmed histological diagnosis. Age at diagnosis, previous non-thyroidal primary malignancy, and radioactive iodine (RAI) therapy have been proposed as independent risk factors for SPM. RAI therapy is a standard treatment for moderate-high risk differentiated thyroid cancer (DTC), and its effect on the development of SPM has become a critical topic in DTC treatment. The purpose of this retrospective single-center study was to investigate the occurrence and the possible association of non-thyroidal SPM diagnosed after DTC and RAI therapy in a cohort of 1326 consecutive DTC patients referred at our Institution for RAI treatment from 1993 to 2009. Eighty-nine patients with ages ≤ 18 years at the time of DTC diagnosis or with a follow-up of ≤12 months were excluded from the final analysis. All patients underwent a complete clinical and hematological follow-up every 6 months for a minimum of 12 months. During follow-up (mean 89 ± 73 months), 25 patients (2%) had an SPM diagnosis (mean 133 ± 73 months). The most common site of the second malignancy was the breast, accounting for 32% of all SPM, followed by colon-rectal cancer (16%), leukemia, and gynecological and kidney cancer (4%). At Cox univariable regression analysis, age at DTC diagnosis (p < 0.001), age ≥55 years (p < 0.001) and follow-up duration (p < 0.004) were associated with SPM onset, while no significant association was observed with the administered activity of radioiodine. In conclusion, our data suggest that the older a person gets, the more sharply the likelihood of developing additional diseases, such as PMS, increases. Similarly, for follow-up, the more a patient is followed up clinically over time, the higher the risk of new diagnoses increases.

Breast cancer risk among thyroid cancer survivors and the role of I-131 treatment

BACKGROUND

Female thyroid cancer survivors are more likely to have a higher risk of breast cancer compared to the general population, and the underlying causes are yet to be understood. The potential role of I-131 treatment on this association remains controversial.

METHODS

We pooled individual data of women who were treated for differentiated thyroid cancer from 1934 to 2005 in France, Italy and Sweden. Standardized incidence ratios (SIRs) for breast cancer were estimated by comparison with age, sex and calendar-year expected values of the general population in each country. We estimated breast cancer risk in relation to I-131 treatment using time-dependent Poisson models.

RESULTS

Of 8475 women (mean age at diagnosis: 45 years, range 2-90 years), 335 were diagnosed with breast cancer [SIR = 1.52, 95% confidence interval (CI): 1.36-1.69] during a median follow-up time of 12.7 years since diagnosis. Overall, breast cancer risk did not differ between women treated or not with I-131 (relative risk=1.07, 95% CI 0.84-1.35). However, breast cancer risk increased with increasing cumulative I-131 activity, without significant departure from linearity (excess relative risk per 100 mCi=17%, 95% CI: 2% to 38%). The higher risk associated with a cumulative I-131 activity of ≥100 mCi and ≥400 mCi was translated into 4 (95% CI -4 to 13) and 42 (95% CI -8 to 93) excess breast cancer cases per 10,000 person-years, respectively.

CONCLUSIONS

An elevated risk was observed for the highest cumulative administered activity (>=400 mCi), and a significant dose-dependent association was observed among thyroid cancer survivors who were treated with I-131. However, overall, I-131 treatment might only explain partly the increase in breast cancer risk among female thyroid cancer survivors.

Towards De-Implementation of low-value thyroid care in older adults

PURPOSE OF REVIEW

This review discusses the current literature regarding low-value thyroid care in older adults, summarizing recent findings pertaining to screening for thyroid dysfunction and management of hypothyroidism, thyroid nodules and low-risk differentiated thyroid cancer.

RECENT FINDINGS

Despite a shift to a "less is more" paradigm for clinical thyroid care in older adults in recent years, current studies demonstrate that low-value care practices are still prevalent. Ineffective and potentially harmful services, such as routine treatment of subclinical hypothyroidism which can lead to overtreatment with thyroid hormone, inappropriate use of thyroid ultrasound, blanket fine needle aspiration biopsies of thyroid nodules, and more aggressive approaches to low-risk differentiated thyroid cancers, have been shown to contribute to adverse effects, particularly in comorbid older adults.

SUMMARY

Low-value thyroid care is common in older adults and can trigger a cascade of overdiagnosis and overtreatment leading to patient harm and increased healthcare costs, highlighting the urgent need for de-implementation efforts.

An immediate postoperative response to therapy assessment can help avoid unnecessary RAI therapy

Background

Radioiodine (RAI) therapy plays a vital role in the postoperative treatment of differentiated thyroid cancer (DTC) patients underwent total thyroidectomy (TT). However, even in the presence of capsular invasion and lymph node metastasis prognosis can be excellent and a postoperative RAI treatment might not be necessary for all patients. Therefore, this study explored the criteria for avoiding unnecessary RAI therapy in these patients.

Method

We applied response to therapy assessment immediately after surgery and prospectively recruited 179 excellent or indeterminate response DTC patients with capsular invasion and/or LNM who underwent TT without RAI therapy. During the follow-up, thyroglobulin (Tg), thyroglobulin antibody (TgAb) levels, and cervical ultrasonography were collected and analyzed. Disease-free survival (DFS) was calculated using the Kaplan-Meier method. In addition, response to therapy assessments was performed on patients during each follow-up.

Results

The mean follow-up period was 29.85 ± 17.44 months, and the 3- and 5-year DFS for all the patients was 99.3% in each. At the last follow-up, 165 (92.2%) patients had excellent responses, while 12 (6.7%) had an indeterminate response, and one (0.6%) each had biochemical and incomplete responses. No significant difference was observed in response to therapy between the subgroups of LNM and tumor invasion (P>0.05). For patients with capsular invasion and a number of metastatic lymph nodes ≤5 and >5, the proportions of recorded excellent responses were 95.9%, 91.0%, and 85.7%, respectively. Better responses were observed in females (excellent response: 95.5%, P=0.023), patients with stimulated Tg (s-Tg) ≤1ng/ml (excellent response: 100%, P<0.001), s-Tg ≤ 2ng/ml (excellent response: 98.4%, P<0.001), and excellent response for the immediate postoperative assessment (excellent response: 98.5%, P=0.004).

Conclusions

The current study suggested that the response to therapy assessment immediately applied postoperatively could help avoid unnecessary RAI therapy among DTC patients with capsular invasion and/or LNM. Moreover, excellent response patients and patients with indeterminate response and s-Tg ≤ 2ng/ml could be managed without RAI therapy.

Association Between Radioactive Iodine Treatment for Pediatric and Young Adulthood Differentiated Thyroid Cancer and Risk of Second Primary Malignancies

PURPOSE

Since the 1980s, both the incidence of differentiated thyroid cancer (DTC) and use of radioactive iodine (RAI) treatment increased markedly. RAI has been associated with an increased risk of leukemia, but risks of second solid malignancies remain unclear. We aimed to quantify risks of second malignancies associated with RAI treatment for DTC in children and young adults, who are more susceptible than older adults to the late effects of radiation.

METHODS

Using nine US SEER cancer registries (1975-2017), we estimated relative risks (RRs) for solid and hematologic malignancies associated with RAI (yes v no or unknown) using Poisson regression among ≥ 5- and ≥ 2-year survivors of nonmetastatic DTC diagnosed before age 45 years, respectively.

RESULTS

Among 27,050 ≥ 5-year survivors (median follow-up = 15 years), RAI treatment (45%) was associated with increased risk of solid malignancies (RR = 1.23; 95% CI, 1.11 to 1.37). Risks were increased for uterine cancer (RR = 1.55; 95% CI, 1.03 to 2.32) and nonsignificantly for cancers of the salivary gland (RR = 2.15; 95% CI, 0.91 to 5.08), stomach (RR = 1.61; 95% CI, 0.70 to 3.69), lung (RR = 1.42; 95% CI, 0.97 to 2.08), and female breast (RR = 1.18; 95% CI, 0.99 to 1.40). Risks of total solid and female breast cancer, the most common cancer type, were highest among ≥ 20-year DTC survivors (RR_solid = 1.47; 95% CI, 1.24 to 1.74; RR_breast = 1.46; 95% CI, 1.10 to 1.95). Among 32,171 ≥ 2-year survivors, RAI was associated with increased risk of hematologic malignancies (RR = 1.51; 95% CI, 1.08 to 2.01), including leukemia (RR = 1.92; 95% CI, 1.04 to 3.56). We estimated that 6% of solid and 14% of hematologic malignancies in pediatric and young adult DTC survivors may be attributable to RAI.

CONCLUSION

In addition to leukemia, RAI treatment for childhood and young-adulthood DTC was associated with increased risks of several solid cancers, particularly more than 20 years after exposure, supporting the need for long-term surveillance of these patients.

Risk factors for second primary malignancies following thyroid cancer: a nationwide cohort study

OBJECTIVE

Thyroid cancer survivors have a high risk of second primary malignancies (SPMs). We aimed to evaluate the site-specific incidence, prognosis, and risk factors for metachronous SPMs following thyroid cancer.

DESIGN

A nationwide cohort study.

METHODS

This study included data from the Korea National Health Insurance Service (between 2002 and 2018). Exposure to diagnostic radiation was defined by the number of computed tomography (CT) and positron emission tomography-CT scans after the index date. A cumulative radioactive iodine (RAI) dose >100 mCi was considered high-dose RAI.

RESULTS

During the median 6 years of follow-up, among 291 640 patients, 13 083 (4.5%) developed SPMs. Thyroid cancer survivors had a 26% increased risk of SPMs compared with the general population (standardized incidence ratio: 1.26; 95% CI: 1.22-1.29). Furthermore, those with SPMs had a significantly poorer survival rate than those without SPMs (hazard ratio: 11.85; 95% CI: 11.21-12.54; P < 0.001). Significantly elevated risks were observed in myeloid leukemia and 13 solid cancer sites: lip, salivary gland, small intestine, larynx, lung, mediastinum and pleura, mesothelium, breast, corpus uteri, ovary, prostate, kidney, and bladder. Frequent diagnostic medical radiation exposure and high-dose RAI therapy were independent risk factors for several SPMs, including the cancer of salivary gland, lung, mediastinum and pleura, breast, kidney, and bladder, as well as myeloid leukemia.

CONCLUSIONS

Frequent diagnostic radiation exposure and high-dose RAI therapy are independent risk factors for SPM following thyroid cancer. Clinicians need to consider minimizing unnecessary diagnostic radiation exposure and administering a high dose RAI only when justified in patients with thyroid cancer.

Trends in the Management of Localized Papillary Thyroid Carcinoma in the United States (2000-2018)

Background: In response to evidence of overdiagnosis and overtreatment of papillary thyroid carcinoma (PTC), the 2009 and 2015 American Thyroid Association (ATA) adult guidelines recommended less extensive surgery (lobectomy vs. total thyroidectomy) and more restricted use of postsurgical radioactive iodine (RAI) in management of PTC at low risk of recurrence. In 2015, active surveillance was suggested as a viable option for some <1-cm PTCs, or microcarcinomas. The 2015 ATA pediatric guidelines similarly shifted toward more restricted use of RAI for low-risk PTCs. The impact of these recommendations on low-risk adult and pediatric PTC management remains unclear, particularly after 2015. Methods: Using data from 18 Surveillance, Epidemiology, and End Results (SEER) U.S. registries (2000-2018), we described time trends in reported first-course treatment (total thyroidectomy alone, total thyroidectomy+RAI, lobectomy, no surgery, and other/unknown) for 105,483 patients diagnosed with first primary localized PTC (without nodal/distant metastases), overall and by demographic and tumor characteristics. Results: The declining use of RAI represented the most pronounced change in management of PTCs <4 cm (44-18% during the period 2006-2018), including microcarcinomas (26-6% during the period 2007-2018). In parallel, an increasing proportion of PTCs were managed with total thyroidectomy alone (35-54% during the period 2000-2018), while more subtle changes were observed for lobectomy (declining from 23% to 17% during the period 2000-2006, stabilizing, and then rising from 17% to 24% during the period 2015-2018). Use of nonsurgical management did not meaningfully change over time, impacting <1% of microcarcinomas annually during the period 2000-2018. Similar treatment trends were observed by sex, age, race/ethnicity, metropolitan vs. nonmetropolitan residence, and insurance status. For pediatric patients (<20 years), use of RAI peaked in 2009 (59%), then decreased markedly to 11% (2018), while use of total thyroidectomy alone and, to a lesser extent, lobectomy increased. No changing treatment trends were observed for ≥4-cm PTCs. Conclusions: The declining use of RAI in management of low-risk adult and pediatric PTC is consistent with changing recommendations from the ATA practice guidelines. Post-2015 trends in use of lobectomy and nonsurgical management of low-risk PTCs, particularly microcarcinomas, were more subtle than expected; however, these trends may change as evidence regarding their safety continues to emerge.

Risk of Second Malignant Neoplasm in Familial Non-Medullary Thyroid Cancer Patients

INTRODUCTION

Survival rates in patients with non-medullary thyroid carcinoma (NMTC) are high, increasing the possibility to develop a second malignant neoplasm (SMN). Many studies investigated the relationship between increased risk of SMN in NMTC patients treated with radioiodine, but few data are available about the impact of family history (FH) of thyroid cancer on SMN risk.

PURPOSE

To assess the risk of SMN in a large cohort of sporadic and familial NMTC using the standardized incidence ratio (SIR).

PATIENTS AND METHODS

We studied 918 NMTC patients (73.9% female patients) followed for a median follow-up of 9 years. In 798/918 (86.9%) patients, NMTC was sporadic, while the remaining 120 (13.1%) were familial NMTC (FNMTC).

RESULTS

We identified 119/918 (13%) patients with SMN in association with NMTC. NMTCs had an increased risk of SMN when compared to the general population (SIR 2.1, 95% CI 1.7-2.5). The rate of SMN for all sites was significantly higher in familial compared to sporadic NMTC (20% versus 11.9%, p = 0.01), primarily driven by families with more than two affected members. The risk of SMN was remarkably higher for breast cancer, especially in familial cases (SIR 22.03, 95% CI 14.4-41.2) compared to sporadic cases (SIR:17, 95% CI 11.9-24.6).

CONCLUSIONS

NMTC patients have a higher risk of SMN compared to the general population and this risk is much higher in patients with FNMTC. This observation raises the hypothesis that genetic risk factors for a first cancer may predispose to SMN, especially among individuals with familial clustering of the same or other tumors.

Side effects of theragnostic agents currently employed in clinical practice

Nuclear medicine plays an increasingly important role in several neoplasms management through a theragnostic approach by which targeted molecular imaging and radiotherapy are obtained with the use of radionuclide pairs with similar characteristics. In some cases, nuclear theragnostic use a pair of agents with identical chemical and biological characteristics while in others are employed theragnostic molecules which are not chemically or biologically identical but show similar biodistribution (so-called "twins in spirit" radiopharmaceuticals). This strategy was developed for the first time over 75 years ago, when iodine-131 was used for diagnostic imaging, confirmation of target expression and radionuclide therapy of thyroid cancer. Other theragnostic approaches were subsequently introduced with significant clinical results and some of them are currently considered standard treatment for different cancers. However, as any other therapy, also nuclear theragnostic treatment carries the potential risk of early deterministic and late stochastic off-target adverse effects, generally minimal and easily managed. This article reviews the reported side effects and risks of the main radiopharmaceuticals used for nuclear theragnostic in oncology for the treatment of thyroid cancer, neuroendocrine neoplasms, adrenergic tumors, metastatic prostate cancer, and liver tumors. Selecting appropriate patients using a multidisciplinary approach, meticulous pretreatment planning and knowledge of methods permit to decrease the incidence of these potential side effects.

Trends in Diagnosis of Noninvasive Follicular Thyroid Neoplasm With Papillarylike Nuclear Features and Total Thyroidectomies for Patients With Papillary Thyroid Neoplasms

Importance

Increasing detection of early-stage papillary thyroid neoplasms without improvements in mortality has prompted development of strategies to prevent or mitigate overtreatment.

Objective

To determine adoption rates of 2 recent strategies developed to limit overtreatment of low-risk thyroid cancers: (1) a new classification, noninvasive follicular thyroid neoplasm with papillarylike nuclear features (NIFTP), and (2) hemithyroidectomy for selected papillary thyroid carcinomas (PTCs) up to 4 cm in size.

Design, Setting, and Participants

This is a cross-sectional analysis of 3368 pathology records of 2 cohorts of patients from 18 hospitals in 6 countries during 2 time periods (2015 and 2019). Participating hospitals were included from the US (n = 12), Canada (n = 2), Denmark (n = 1), South Korea (n = 1), South Africa (n = 1), and India (n = 1). The records of the first 100 patients per institution for each year who underwent thyroid-directed surgery (hemithyroidectomy, total thyroidectomy, or completion thyroidectomy) were reviewed.

Main Outcomes and Measures

Frequency of diagnosis of NIFTP, PTCs, and thyroidectomies during the study period.

Results

Of the 790 papillary thyroid neoplasms captured in the 2019 cohort, 38 (4.8%) were diagnosed as NIFTP. Diagnosis of NIFTP was observed in the US, South Africa, and India. There was minimal difference in the total proportion of PTCs in the 2015 cohort compared with the 2019 cohort (778 [47.1%] vs 752 [44.5%]; difference, 2.6% [95% CI, -16.9% to 22.1%]). The proportion of PTCs eligible for hemithyroidectomy but treated with total thyroidectomy in the 2 cohorts demonstrated a decreasing trend from 2015 to 2019 (341 of 453 [75.3%] vs 253 of 434 [58.3%]; difference, 17.0% [95% CI, -1.2% to 35.2%]).

Conclusions and Relevance

Results of this cohort study showed that the 2 mitigation strategies for preventing overtreatment of early-stage thyroid cancer have had mixed success. The diagnosis of NIFTP has only been applied to a small proportion of thyroid neoplasms compared with expected rates. However, more patients eligible for hemithyroidectomy received it in 2019 compared with 2015, showing some success with this deescalation strategy.

Risk of thyroid as a first or second primary cancer. A population-based study in Italy, 1998-2012

BACKGROUND

The number of patients living after a cancer diagnosis is increasing, especially after thyroid cancer (TC). This study aims at evaluating both the risk of a second primary cancer (SPC) in TC patients and the risk of TC as a SPC.

METHODS

We analyzed two population-based cohorts of individuals with TC or other neoplasms diagnosed between 1998 and 2012, in 28 Italian areas covered by population-based cancer registries. Standardized incidence ratios (SIRs) of SPC were stratified by sex, age, and time since first cancer.

RESULTS

A total of 38,535 TC patients and 1,329,624 patients with other primary cancers were included. The overall SIR was 1.16 (95% CI: 1.12-1.21) for SPC in TC patients, though no increase was shown for people with follicular (1.06) and medullary (0.95) TC. SPC with significantly increased SIRs was bone/soft tissue (2.0), breast (1.2), prostate (1.4), kidney (2.2), and hemolymphopoietic (1.4) cancers. The overall SIR for TC as a SPC was 1.49 (95% CI: 1.42-1.55), similar for all TC subtypes, and it was significantly increased for people diagnosed with head and neck (2.1), colon-rectum (1.4), lung (1.8), melanoma (2.0), bone/soft tissue (2.8), breast (1.3), corpus uteri (1.4), prostate (1.5), kidney (3.2), central nervous system (2.3), and hemolymphopoietic (1.8) cancers.

CONCLUSIONS

The increased risk of TC after many other neoplasms and of few SPC after TC questions the best way to follow-up cancer patients, avoiding overdiagnosis and overtreatment for TC and, possibly, for other malignancies.

Pathological findings of the retrospective diagnosis of NIFTP (non-invasive follicular thyroid neoplasm with papillary-like nuclear features) in 84 cases from Turkey and systematic review

AIM

The terminology of "noninvasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP) was introduced in 2016; and estimated to cause significant effects in the clinical management of thyroid nodules. The aim of our study is to review our cases that were previously diagnosed as non-invasive encapsulated follicular variant PTC (NI/E-FVPTC) which are compatible with NIFTP and to correlate their follow-up.

METHOD

All thyroidectomy cases evaluated in the last 15 years were screened, and possible NIFTP cases were determined among patients with NI/E-FVPTC and they were re-examined microscopically. Revised histopathological criteria were used for the retrospective diagnosis of NIFTP. Histopathological findings were correlated to follow up information.

RESULTS

Totally 2138 cases had been previously diagnosed with PTC; 481 (22.5%) of them were FVPTC. After microscopic reevaluation of potential NIFTP cases, 84 cases (3.9%) received final diagnosis of NIFTP. 78.6% of NIFTP patients were female (F/M: 66/18); mean age was 49.0, tumor diameter was 22.7 mm and follow-up time was 66.4 months. 17.9% of NIFTP cases were multifocal and 13.1% were bilateral. No recurrence, lymph node involvement or distant metastasis was detected in any of the patients who were followed up. The mean age of the patients who had total thyroidectomy and received RAI was significantly higher than those who did not.

CONCLUSION

Although conservative treatment of NIFTP with lobectomy is recommended, age of the patients has been continuing to be the most important determinant for the clinicians to decide on total thyroidectomy and RAI ablation therapy at our institution.

An aqueous extract of Prunella vulgaris L. inhibits the growth of papillary thyroid carcinoma by inducing autophagy in vivo and in vitro

The continued global rise in papillary thyroid carcinoma (PTC) combined with potential adverse effects of regular treatments calls for an alternative therapy. Prunella vulgaris L. (PV) is commonly used as a herbal remedy for thyroid diseases in China, but its influence on PTC is unclear. This study investigated the effect of PV aqueous extract on PTC and its underlying mechanism using a mouse xenograft model and the human PTC cell line K1. PV suppressed tumor growth in PTC-bearing mice at 0.05 and 0.1 g/kg bw, accompanied by improvements in autophagy-related protein expressions in xenografts. In K1 cells, PV inhibited cell growth and induced autophagic flux, manifesting as changes in autophagy-related proteins, the presence of autophagosomes, and a further increase in LC3-II by co-incubation with bafilomycin A1. Autophagy inhibitor 3-methyladenine ameliorated the autophagic cell death caused by PV. The mammalian target of rapamycin (mTOR) activator MHY1485 blocked the antiproliferative activity of PV by regulating mTOR, unc-51-like autophagy activating kinase 1 (ULK1), autophagosomes formation, and autophagy-related proteins. The adenosine monophosphate-activated protein kinase (AMPK) inhibitor compound C attenuated PV-induced inhibition of mTOR. Our results suggest that PV inhibits the growth of PTC in vivo and in vitro via autophagy, which is associated with the AMPK/mTOR/ULK1 pathway. Thus, PV has the potential to function as a therapeutic agent against PTC.

Total Thyroidectomy vs Thyroid Lobectomy for Localized Papillary Thyroid Cancer in Children: A Propensity-Matched Survival Analysis

BACKGROUND

Current guidelines recommend total thyroidectomy (TT) and radioablation for most papillary thyroid cancer (PTC) in children. These guidelines have been criticized as aggressive, especially for early-stage PTC, as it likely does not influence patient survival and results in life-long thyroid hormone replacement. We sought to study whether the extent of thyroidectomy (TT vs thyroid lobectomy [TL]) influences overall and disease-specific survival in children with localized PTC.

METHODS

The National Cancer Database and the Surveillance, Epidemiology, and End Results registries were queried. Patients 18 years or younger with low-risk PTC between 2004 and 2016 were included. Using a 1:1 propensity score matching, patients who underwent TT were matched for age, sex, race, year of diagnosis, and tumor size with a similar cohort of patients who underwent TL. Primary end points were overall survival and disease-specific survival.

RESULTS

There were 3,500 patients identified as surgically treated for PTC, of which 1,325 patients met inclusion criteria for matching. Three hundred and twenty-six patients were matched. One hundred and sixty-three patients had TT; 140 were female and mean age was 16 years (interquartile range [IQR] 13 to 17 years). One hundred and sixty-three patients had TL; 140 were female and mean age was 16 years (IQR 14 to 17 years). Median follow-up was 5.0 years (IQR 2.8 to 8 years) and 8.3 years (IQR 3.6 to 14.4 years) in the National Cancer Database and Surveillance, Epidemiology, and End Results cohorts, respectively. There was no statistically significant difference in overall survival or disease-specific survival in patients with PTC < 4 cm, regardless of whether patients underwent TT or TL (p = 0.32 for National Cancer Database registry and p = 0.67 for Surveillance, Epidemiology, and End Results registry).

CONCLUSIONS

This study suggests that the extent of thyroidectomy does not influence survival for pediatric patients with early-stage PTC and that TL might be adequate in this patient population.

Changes in Population-Level and Institutional-Level Prescribing Habits of Radioiodine Therapy for Papillary Thyroid Cancer

Background: In the past two decades, new evidence and guidelines have emerged to refine recommendations for the use of radioactive iodine (RAI) therapy after thyroidectomy for cancer. We aim to describe national trends in RAI utilization, assess the impact of individual hospitals on RAI utilization, and examine whether variation in prescribing habits has declined over time. Methods: The National Cancer Database (NCDB) was queried from 2004 to 2016 for patients with papillary thyroid cancer (PTC) who received total thyroidectomy. Trends were analyzed using Joinpoint analysis. Hospital-specific effects and variation in prescribing habits were assessed through a hierarchical, mixed regression model. Results: RAI utilization declined from 61.0% in 2004 to 43.9% in 2016. RAI use declined most profoundly in patients with T1a, N0/X, M0 PTC without extrathyroidal extension (34.8% in 2004 to 9.5% in 2015), but continues to be used commonly in patients with advanced disease for whom it is routinely recommended (73.4% in 2004 to 72.0% in 2015). Furthermore, ∼80% of hospitals in 2016 utilized at or below the median utilization rate in 2006. Variation in RAI utilization across hospitals decreased by ∼50% from 2004 to 2016 (Levene's test p < 0.001), with a significant decline (p = 0.002) in the variation after 2012 (confidence interval: 2010 to 2014). Conclusions: Recommendations for whom to prescribe RAI appear to have impacted both the number of patients receiving RAI and the variation in prescribing habits across hospitals. Hospital selection has contributed less to the probability of receiving RAI over time.

Impact of Dyslipidemia on the Risk of Second Cancer in Thyroid Cancer Patients: A Korean National Cohort Study

BACKGROUND

Studies have shown that radioactive iodine therapy (RAIT) affects the development of second cancer in thyroid cancer patients. The impact of other factors, such as dyslipidemia are not clear.

METHODS

A retrospective analysis of thyroid cancer patients with a 1,251,913 person-year follow-up was conducted using data from the Health Insurance Review and Assessment database in South Korea from January 2008 to December 2018. We investigated factors related to second cancer development using a nested case-control analysis to avoid length bias.

RESULTS

The overall risk of developing second cancer was higher in thyroid cancer patients than in the general population [standardized incidence ratio, 3.34; 95% confidence interval (CI) 3.30-3.39]. Second cancer incidence was higher in patients who received RAIT than in those who did not [odds ratio (OR) 1.130; 95% CI 1.094-1.169]. Moreover, the risk of second cancer was higher in patients with dyslipidemia than in those without dyslipidemia (OR 1.265; 95% CI 1.223-1.309). After adjustment for RAIT, the incidence of a second cancer was higher in patients with dyslipidemia than in those without dyslipidemia (OR 1.262; 95% CI 1.221-1.306).

CONCLUSIONS

The risk of second cancer development in patients with thyroid cancer appears to be high. Dyslipidemia may be associated with an increased risk of several types of second cancers.

Radiofrequency Ablation for Cervical Metastatic Lymph Nodes in Children and Adolescents With Papillary Thyroid Carcinoma: A Preliminary Study

OBJECTIVE

To evaluate the safety and efficacy of radiofrequency ablation (RFA) for metastatic lymph nodes (LNs) in children and adolescents with papillary Thyroid Carcinoma (PTC).

MATERIALS AND METHODS

From December 2014 to March 2018, 10 metastatic LNs(mean volume 0.30 ± 0.38 ml, range 0.06-1.23ml) in 5 children and adolescents (3 females, 2 males; mean age 15.60 ± 2.97 years, range 12-19 years) with PTC treated by RFA were evaluated in this study. The mean number of surgical procedures performed before RFA was 1.2 (range 1-2) and the mean number of treated metastatic LNs per patient was 2 (rang 1-3). RFA was performed with an 18-gauge bipolar RF applicator under local anesthesia. Follow-up consisted of US and serum thyroglobulin (Tg) level at 1, 3, 6, 12 months and every 12 months thereafter.

RESULTS

All the patients were well tolerant to RFA procedure and no procedure-related complications occurred. During a mean follow-up time of 52.00 ± 21.44 months, the initial volume of LNs was 0.30 ± 0.38 ml, which significantly decreased to 0.01 ± 0.03 ml (P = 0.005) with a mean VRR of 99.28 ± 2.27%. A total of 9 metastatic LNs (90.00%) completely disappeared. After RFA, 2 patients developed newly metastases. One patient had additional RFA. The other one with multiple LN metastases underwent total thyroidectomy with central neck dissection.

CONCLUSION

As a less invasive and effective technique, RFA may provide another alternative to the existing therapeutic modalities for cervical metastatic LNs in children and adolescents with PTC.

Molecular Imaging in the Head and Neck: Diagnosis and Therapy

This article is a summary of the most up-to-date applications of radiopharmaceuticals to the diagnosis and therapy of benign and malignant diseases involving endocrine or neuroendocrine organs of the head and neck, focusing on radiotracers approved by the US Food and Drug Administration, such as I-123- and I-131-sodium iodide, F-18-fluorodeoxyglucose, Tc99m-sestamibi, as well as the more recently approved tracers Ga-68 DOTATATE and Lu-177 DOTATATE.

Long-term all-cause mortality and its association with cardiovascular risk factors in thyroid cancer survivors: an Israeli population-based study

BACKGROUND

The global incidence of thyroid cancer (TC) has risen considerably during the last three decades, while prognosis is generally favorable. We assessed the long-term all-cause mortality in TC survivors compared to the general population, and its association with cardiovascular risk factors.

METHODS

Individuals diagnosed with TC during 2001-2014 (TC group) and age- and sex-matched individuals from the same Israeli healthcare system without thyroid disease or a cancer history (non-TC group) were compared. Cox regression hazard ratios (HRs) and 95% confidence intervals (95%CIs) for all-cause mortality were calculated by exposure status.

RESULTS

During a 15-year follow-up (median 8 years), 577 TC survivors out of 5677 (10.2%) TC patients and 1235 individuals out of 23,962 (5.2%) non-TC patients died. The TC survivors had an increased risk of all-cause mortality (HR = 1.89, 95%CI 1.71-2.10), after adjusting for cardiovascular risk factors already present at follow-up initiation. This increased risk was most pronounced in the 55- to 64-year-old age group (HR = 1.49, 95%CI 1.33-1.67). The TC survivors who died by study closure had more hypertension (14.6% vs. 10.3%, P = 0.002), more dyslipidemia (11.4% vs. 7.2%, P <  0.001), and more cardiovascular disease (33.6% vs. 22.3%, P = 0.05) compared to those who died in the non-TC group.

CONCLUSIONS

This large cohort study showed higher all-cause mortality with a higher prevalence of hypertension, dyslipidemia, and cardiovascular disease among TC survivors compared to matched non-TC individuals. Primary and secondary prevention of cardiovascular risk factors in TC survivors is mandatory.

Randomised comparison of 1.1 GBq and 3.7 GBq radioiodine to ablate the thyroid in the treatment of low-risk thyroid cancer: a 13-year follow-up

Purpose: The optimal activity of radioiodine (I-131) administered for ablation therapy in papillary and follicular thyroid cancer after thyroidectomy remains unknown in a long-term (> 10 year) follow-up. Some, shorter follow-up studies suggest that activities 1.1 GBq and 3.7 GBq are equally effective. We evaluated the long-term outcomes after radioiodine treatment to extend current knowledge about the optimal ablative dose of I-131.Methods: One hundred and sixty consecutive adult patients (129 females, 31 males; mean age 46 ± 14 y, range 18-89 y) diagnosed with histologically confirmed differentiated thyroid cancer, were randomised in a prospective, phase III, open-label, single-centre study, to receive either 1.1 GBq or 3.7 GBq of I-131 after thyroidectomy. At randomisation, patients were stratified according to the histologically verified cervical lymph node status and were prepared for ablation using thyroid hormone withdrawal. No uptake in the whole-body scan with I-131 and serum thyroglobulin concentration less than 1 ng/mL at 4-8 months after treatment was considered successful ablation.Results: Median follow-up time was 13.0 years (mean 11.0 ± 4.8 y; range 0.3-17.1 y). Altogether 81 patients received 1.1 GBq with successful ablation in 45 (56%) patients. In the original study, thirty-six patients (44%) needed one or more extra administrations to replete the ablation. Of these, 4 (8.9%) and 5 (14%) patients relapsed during the follow-up, respectively. Of the 79 patients treated with 3.7 GBq 45 (57%) had successful ablation after one administration of radioiodine and 34 (43%) needed several treatments. Of these, 2 (4.4%) and 9 (26.5%) patients relapsed, respectively. The groups did not differ in the proportion of patients relapsing (p = .591).Conclusion: During follow-up of median 13 years, 3.7 GBq is not superior to 1.1 GBq in the radioiodine treatment after thyroidectomy in papillary and follicular thyroid cancer.

Salivary and lacrimal dysfunction after radioactive iodine for differentiated thyroid cancer: American Head and Neck Society Endocrine Surgery Section and Salivary Gland Section joint multidisciplinary clinical consensus statement of otolaryngology, ophthalmology, nuclear medicine and endocrinology

BACKGROUND

Postoperative radioactive iodine (RAI) administration is widely utilized in patients with differentiated thyroid cancer. While beneficial in select patients, it is critical to recognize the potential negative sequelae of this treatment. The prevention, diagnosis, and management of the salivary and lacrimal complications of RAI exposure are addressed in this consensus statement.

METHODS

A multidisciplinary panel of experts was convened under the auspices of the American Head and Neck Society Endocrine Surgery and Salivary Gland Sections. Following a comprehensive literature review to assess the current best evidence, this group developed six relevant consensus recommendations.

RESULTS

Consensus recommendations on RAI were made in the areas of patient assessment, optimal utilization, complication prevention, and complication management.

CONCLUSION

Salivary and lacrimal complications secondary to RAI exposure are common and need to be weighed when considering its use. The recommendations included in this statement provide direction for approaches to minimize and manage these complications.

New paradigms in the treatment of low-risk thyroid cancer

INTRODUCTION

Thyroid cancer is the most common endocrine malignancy. Multiple different staging systems have been introduced and used for differentiated thyroid carcinoma (DTC).

AREAS COVERED

In this literature review we provide an overview of the standard options for management of patients with low risk differentiated thyroid cancer.

EXPERT OPINION

Surgery is considered the first and most important step in managing DTC with goal to remove all the malignant foci in order to achieve cure and increase the survival with least chance of recurrence. Many studies have been conducted to determine the best surgical approaches and how aggressive surgeries should be in order to achieve the best outcomes regarding efficacy as well as safety. Radioactive iodine (RAI) therapy has also been a part of the treatment regimen and is used for different purposes with three main goals: post-surgical ablation, adjuvant therapy and persisted/recurrent disease treatment. Radiation therapy, on the other hand, is still not recommended to be used routinely in DTC because of the conflicting data of its benefit.

The benefits of radioactive iodine ablation for patients with intermediate-risk papillary thyroid cancer

BACKGROUND

The beneficial effects of radioactive iodine (RAI) ablation for intermediate-risk papillary thyroid cancer (PTC) patients are still controversial.

MATERIALS AND METHODS

To determine the impact of RAI therapy on disease-specific survival (DSS) in patients with intermediate-risk PTC, we retrospectively analyzed the data of 23107 intermediate-risk PTC patients who underwent primary thyroidectomy with or without RAI in the Surveillance, Epidemiology, and End Results (SEER) database.

RESULTS

RAI therapy was significantly associated with improved DSS (adjusted HR = 0.65, P = 0.017) in intermediate-risk PTC patients after multivariate adjusting for clinicopathological characteristics. However, subgroup analyses demonstrated that RAI ablation was only associated with improved DSS in patients with male gender (adjusted HR = 0.47, P = 0.005), age ≥ 45 years (adjusted HR = 0.34, P < 0.001) and tumor size > 20 mm (adjusted HR = 0.58, P = 0.007).

CONCLUSION

RAI decision-making should be considered on an individual basis rather than "one size fits all" in intermediate-risk PTC patients; only patients with male gender, age ≥ 45 years, and tumor size > 20 mm may benefit from RAI therapy.

The impact of radioactive iodine treatment on survival among papillary thyroid cancer patients according to the 7th and 8th editions of the AJCC/TNM staging system: a SEER-based study

Papillary thyroid cancer is a very common endocrine malignancy. The 8th American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) staging system introduced major changes. We conducted this retrospective cohort analysis to assess the benefits of radioactive iodine (RAI) according to different stratification of patients. The source of the data was the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database. From 2006 to 2015, patients with papillary thyroid cancer were included in our study. The interactions between different variables and RAI treatment were tested by multivariate Cox regression models to compare the survival differences according to RAI treatment between the patients assessed with the 7th and 8th edition of the AJCC/TNM staging system. The results of the interaction analysis and group comparisons indicated that the effects of RAI treatment on patients staged with the 7th and 8th editions were similar. Patients with early Stage, early T stage, N0 and subtotal or near total thyroidectomy benefited greatly from RAI treatment. Patients with Stage III according to the 8th edition benefited less from RAI than patients with Stage III according to the 7th edition. Patients with T1a benefited from RAI but benefited less than patients with other T stages. Patients with T3a benefited more from RAI than those with T3b. According to the 8th edition, Stage III/IV more accurately differentiates patients with advanced stage disease. These patients benefitted less from RAI treatment, which may be due to the relatively weaker iodine uptake by tumor cells. T1a patients benefitted less than patients with other T stages. The difference in RAI benefit between patients with T3a and T3b is a novel finding in our study.

Parallels Between Low-Risk Prostate Cancer and Thyroid Cancer: A Review

Importance

Across many countries, a rapid escalation of the incidence of thyroid cancer has been observed, a surge that nonetheless underestimates the true extent of the disease. Most thyroid cancers now diagnosed comprise small, low-risk cancers that are incidentally found and are unlikely to cause harm. In many ways, prostate cancer similarly harbors a well-behaved subclinical reservoir, a long natural history, and superlative outcomes that have made active surveillance the de facto guideline recommendation for low-risk disease. This review highlights the parallels and differences between prostate cancer and thyroid cancer regarding screening, diagnosis, risk stratification, and considerations for active surveillance.

Observations

Prostate cancer and thyroid cancer have undergone recalibrated, de-escalatory shifts to counter changing epidemiologic landscapes. The US Preventive Services Task Force has issued cautionary recommendations on screening via prostate-specific antigen testing or neck ultrasonography, while the thresholds to performing biopsy have increased. Comparable changes to cancer terminology and staging have also helped alleviate patient anxiety and minimize pressure for overtreatment. Long-term, randomized prospective clinical trials for prostate cancer have established active surveillance as a first-line treatment approach for properly stratified low-risk patients, while observational trials for thyroid cancer have also made strides in defining risk and eligibility for surgery. Caveats requiring deeper investigation include aggressive disease in older patients, underestimation of the extent of the disease, and patient-physician bias in shared decision making. For prostate cancer, survival may not improve and function will likely worsen after intervention; for thyroid cancer, patients are younger, surgery is safer, and the bar for surveillance will likely be higher.

Conclusions and Relevance

Despite similarities in biological indolence between low-risk prostate and thyroid malignant neoplasms, key distinctions in life expectancy and treatment sequelae may ultimately confer somewhat disparate management paradigms for the 2 diseases. Nevertheless, the experience forged by prostate cancer trials serves as a model for thyroid cancer management, potentially reshaping the perception of active surveillance into a credible, valuable treatment modality.

The role of radioactive iodine in the management of patients with differentiated thyroid cancer - An oncologic surgical perspective

With improved understanding of the biology of differentiated thyroid carcinoma its management is evolving. The approach to surgery for the primary tumour and elective nodal surgery is moving from a "one-size-fits-all" recommendation to a more personalised approach based on risk group stratification. With this selective approach to initial surgery, the indications for adjuvant radioactive iodine (RAI) therapy are also changing. This selective approach to adjuvant therapy requires understanding by the entire treatment team of the rationale for RAI, the potential for benefit, the limitations of the evidence, and the potential for side-effects. This review considers the evidence base for the benefits of using RAI in the primary and recurrent setting as well as the side-effects and risks from RAI treatment. By considering the pros and cons of adjuvant therapy we present an oncologic surgical perspective on selection of treatment for patients, both following pre-operative diagnostic biopsy and in the setting of a post-operative diagnosis of malignancy.

Analysis of patterns and risk factors regarding the onset of nodules in the contralateral thyroid lobe during follow-up ultrasonography among patients after unilateral lobectomy for the treatment of papillary thyroid carcinoma

BACKGROUND

This study tries to find the patterns of new nodules in contralateral thyroid lobe among papillary thyroid carcinomas (PTCs) after lobectomy using ultrasonography.

METHODS

Of note, 456 PTCs were enrolled. Clinicopathological features of primary tumors and sonographic patterns of new nodules in contralateral lobe were documented. Logistic regression analysis was performed to identify risk factors for new nodules.

RESULTS

The overall incidence of new nodules was 41.9%. 96.3% of new nodules were no greater than 1 cm while only 10.5% of those were with high suspicion of malignancy. There was no difference in the incidence and sonographic patterns of new nodules between patients with an original tumor size <1 cm (n = 267) vs 1 to 4 cm (n = 189). Multivariate logistic regression analysis showed age (OR, 1.021; 95% CI, 1.001-1.041; P = .036) played risk factor for new nodules while tumor size >1 cm did not.

CONCLUSION

New nodules in the contralateral lobe were common, but usually small and benign by ultrasound features. Older age was found to be a risk factor to predict new nodules. This study supports lobectomy for 1-4 cm PTC in terms of incidence of new nodules on the remnant lobe.

The Need for Completion Thyroidectomy in Cases of Differentiated Thyroid Cancer

There are no definitive criteria for the presence of malignancy in the opposite lobe in cases of unilateral lobectomy due to a thyroid mass in which the malignancy was diagnosed histologically. Study design is retrospective, cross sectional study. The present study included patients who underwent a lobectomy in our clinic between 2001 and 2016 with an initial diagnosis of atypia with undetermined significance or suspected malignancy according to fine-needle aspiration biopsy and adult patients who received a thyroidectomy based on thyroid cancer detected in pathological examinations. Tumor histopathological diagnosis, tumor size, and capsular, vascular, or lymphatic invasion were assessed in patients who received thyroid lobectomy. The presence of a multifocal tumor (52.3%) significantly increased the risk of malignancy in the opposite lobe over the risk association with a unifocal tumor (8.9%; p < 0001). In patients with a tumor diameter greater than 4 cm (83.3%), the risk of malignancy in the opposite lobe was higher than that in patients with a tumor diameter less than 4 cm (22.3%; p < 0.001). Significant differences were not observed between groups with and without vascular or capsular invasion of the opposite lobe (p = 0.913 and p = 0.840, respectively). We determined risk factors for the presence of multifocal disease in unilateral lobectomy materials; an aggressive tumor subtype and a size larger than 4 cm are the most important factors that increase the risk of malignancy in the opposite lobe. Level of evidence Level 4-Case-control studies.

Radioactive iodine in differentiated thyroid cancer: a national database perspective

Radioactive iodine (RAI) is a key component in the treatment of differentiated thyroid cancer. RAI has been recommended more selectively in recent years as guidelines evolve to reflect risks and utility in certain patient subsets. In this study we sought to evaluate the survival impact of radioactive iodine in specific thyroid cancer subgroups. Nationwide retrospective cohort study of patients using the National Cancer Database (NCDB) from 2004 to 2012 and Surveillance, Epidemiology, and End Results (SEER) database from 1992 to 2009 examining patients with differentiated thyroid cancer treated with or without RAI. Primary outcomes included all-cause mortality (NCDB and SEER), and cancer-specific mortality (SEER). Cox multivariate survival analyses were applied to each dataset, and in 135 patient subgroups based on clinical and non-clinical parameters. A total of 199,371 NCDB and 77,187 SEER patients were identified. RAI was associated with improved all-cause mortality (NCDB: RAI hazard ratio (HR) 0.55, P < 0.001; SEER: HR 0.64, P < 0.001); and cancer-specific mortality (SEER: HR 0.82, P = 0.029). Iodine therapy showed varied efficacy within each subgroup. Patients with high-risk disease experienced the greatest benefit in all-cause mortality, followed by intermediate-risk, then low-risk subgroups. Regarding cancer-specific mortality, radioactive iodine therapy was protective in high-risk patients, but did not achieve statistical significance in most intermediate-risk subgroups. Low-risk T1a subgroups demonstrated an increased likelihood of cancer-specific mortality with iodine therapy. The efficacy of RAI in patients with differentiated thyroid cancer varies by disease severity. A negative cancer-specific survival association was identified in patients with T1a disease. These findings warrant further evaluation with prospective studies.

Initial treatment of pediatric differentiated thyroid cancer: a review of the current risk-adaptive approach

Differentiated thyroid cancer in children is a rare disease, accounting for only 1.4% of all pediatric malignancies. The diagnosis, biological behavior and treatment of differentiated thyroid cancer in children is different from that in adults. While there are many unresolved issues regarding approaches to management of differentiated thyroid cancer in the pediatric population, there is near universal consensus that treatment of this disease, which includes total thyroidectomy, central lymph node dissection at the time of initial surgery in those with nodal metastases, and the possible use of iodine-131 radiotherapy, is best performed by specialists including high-volume endocrine surgeons and experts with experience in calculating and administering radioactive iodine in children, when deemed appropriate.

Analysis of lncRNA and mRNA Transcriptomes Expression in Thyroid Cancer Tissues Among Patients With Exposure of Medical Occupational Radiation

Background:

Occupational exposure of radiation among medical radiation workers contributes to the subsequent increased risk of thyroid cancer. Long noncoding RNAs (lncRNAs) are emerging as important regulators of cancer biology. However, little is known about lncRNA expression in thyroid cancer tissues from patients who are exposed to medical occupational radiation. The purpose of this study is to reveal the transcriptomes difference between thyroid cancer tissues and adjacent nonneoplastic thyroid tissues.

Methods:

Microarray technology was used in this study. Quantitative reverse transcription polymerase chain reaction was adopted to verify 6 differentially expressed lncRNAs. Gene ontology and pathway analyses were performed using standard enrichment computational methods. Potential target genes of the differentially expressed lncRNAs were predicted with 2 independent algorithms.

Results:

A total of 23 lncRNA and messenger RNA transcripts were found differentially expressed in the thyroid cancer tissues (fold change ≥2.0, P < .05). This differential lncRNA expression may affect many pathways, including those involved in cysteine and methionine metabolism, Huntington disease, propanoate metabolism, and carcinogenesis.

Conclusions:

Our study provides a transcriptome-wide screening and analysis of the lncRNA expression profile in thyroid cancer tissues from patients with medical occupational radiation exposure and lays the foundation for further investigation of lncRNAs related to thyroid cancer development and carcinogenic risk of medical occupational radiation exposure.

NIS and epithelial-mesenchymal transition marker expression of circulating tumor cells for predicting and monitoring the radioactive iodine-131 therapy effect in differentiated thyroid cancers

Current methods, such as serum thyroglobulin measurement and medical imaging, have limitations in the routine monitoring of the disease status and treatment response of patients with differentiated thyroid cancers (DTCs), and additional methods remain to be explored. The aim of this study was to investigate the clinical value of the sodium/iodide symporter (NIS) expression and epithelial-mesenchymal transition (EMT) phenotypes of circulating tumor cells (CTCs) in monitoring the disease status and treatment response of DTC. Blood samples were obtained from DTC patients before (1 to 3 months after total thyroidectomy) and 4 to 6 months after radioactive iodine-131 (RAI) therapy for the CTC assessments. The number, NIS expression, and EMT phenotypes of CTCs were enumerated and characterized with CanPatrol™ CTC enrichment and mRNA in situ hybridization. Postoperative NIS high expression was independently correlated with a better response to first RAI therapy and good treatment efficacy. Postoperative NIS-/epithelial-/mesenchymal+ CTCs presence was independently correlated with a worse response to first RAI therapy. The numbers of total NIS+ CTCs and NIS+/epithelial+/mesenchymal+ CTCs after first RAI therapy were negatively correlated with a better response to RAI therapy only in univariate analyses. Univariate and multivariate analyses showed that a decreased or unchanged number of total NIS+ CTCs after RAI therapy may denote good efficacy and effective RAI therapy. These preliminary data suggest that assessment of the NIS expression and EMT phenotypes of CTCs may serve as potential adjuncts for predicting and monitoring the curative effect of RAI therapy in DTC patients and avoid ineffective treatment. Further validation is warranted.

Downregulation of TSPAN13 by miR-369-3p inhibits cell proliferation in papillary thyroid cancer (PTC)

Previous studies demonstrated dysregulation of different microRNAs in thyroid cancer. Tetraspanins (TSPANs) are cell surface proteins with critical roles in many cellular processes, and implications in tumor development. Here we investigated the role of miR-369-3p in papillary thyroid cancer (PTC) and its association with TSPAN13. miR-369-3p and the TSPAN13 gene expression profiles of 513 thyroid cancer and 59 normal thyroid tissues were downloaded from the Cancer Genome Atlas database. Thyroid cancer tissues were classified according to the histological type, grouped based on low and high median miR-369-3p and TSPAN13 expression, and analyzed in relation to overall survival (OS) of patients. Human PTC cell lines (TPC-1 and GLAG-66) and human embryonic kidney 293T (HEK293T) cells were used for in vitro analysis. Transfection experiments were performed with synthetic miRNA mimics for miR-369-3p and small interfering RNAs for TSPAN13. Relative expression of miR-369-3p and TSPAN13 mRNA was determined by RT-qPCR. Protein levels of TSPAN13 were determined by western blotting. Cell proliferation (CCK-8 assay), colony formation, and apoptosis (flow cytometry) were analyzed in transfected cells. Binding sites of miR-369-3p in TSPAN13 mRNA were determined by bioinformatics analysis and dual luciferase reporter assay. miR-369-3p was downregulated and TSPAN13 upregulated in PTC, follicular thyroid cancer, and tall cell variant tissues. Both low expression of miR-369-3p and high expression of TSPAN13 were associated with shorter OS in thyroid cancer patients. Overexpression of miR-369-3p significantly suppressed proliferation and promoted apoptosis in PTC cells. TSPAN13 was a direct target of miR-369-3p, and silencing of TSPAN13 phenocopied the effect of miR-369-3p mimics in PTC cells. Overall, the downregulation of miR-369-3p and consequent upregulation of its target TSPAN13 appear to be involved in pathophysiology of PTC.

Long-term outcomes of renal function after radioactive iodine therapy for thyroid cancer according to preparation method: thyroid hormone withdrawal vs. recombinant human thyrotropin

PURPOSE

Long-term effects of iatrogenic hypothyroidism on renal function from thyroid hormone withdrawal during radioactive iodine therapy (RAIT) have not been studied, especially in subjects with mildly impaired renal function. We compared renal function in thyroid cancer subjects according to preparation method of either thyroid hormone withdrawal (THW) or injection of recombinant human thyrotropin (rhTSH).

METHODS

This retrospective study enrolled 241 thyroidectomized patients (rhTSH group, n = 87 and THW group, n = 154). Changes in glomerular filtration rate (GFR) were measured prior to surgery, at the time of RAIT, and during a regular follow-up at least one year after RAIT.

RESULTS

Baseline renal function was comparable between the rhTSH group and the THW group (91.4 mL/min/1.73 m² vs. 92.4 mL/min/1.73 m²). At the time of RAIT, GFR was significantly decreased in the THW group (70.6 mL/min/1.73 m², -23.6%), whereas renal function was preserved in the rhTSH group (85.4 mL/min/1.73 m², -6.6%). In the THW group, renal function was fully recovered within 6 months after RAIT and was maintained up to 24 months, even in subjects with baseline GFR less than 90 mL/min/1.73 m².

CONCLUSIONS

THW for RAIT preparation induced considerable reduction in renal function, but this change was transient. In contrast, injection of rhTSH did not decrease renal function, making it a good option for RAIT preparation for subjects with renal dysfunction.

In properly selected patients with differentiated thyroid cancer, antithyroglobulin antibodies decline after thyroidectomy and their sole presence should not be an indication for radioiodine ablation

OBJECTIVE

Our objective was to evaluate the trend of antithyroglobulin antibodies (TgAb) during follow-up of patients with differentiated thyroid cancer (DTC) treated without RAI, as well as their role in the risk of recurrence.

SUBJECTS AND METHODS

This was a prospective, descriptive study. A total of 152 consecutive patients with DTC treated in a single institution undergoing total thyroidectomy without RAI and followed for a median of 2.3 years (0.5-10.3) were divided in two groups: TgAb(-) (n = 111) and TgAb(+) (n = 41). Patients were classified according to AJCC 7th and 8th editions, as well as to their risk of recurrence and response to treatment categories.

RESULTS

Both groups, TgAb(-) and TgAb(+), were similar regarding patient and tumor characteristics. At the end of follow-up, 90 (59.2%), 57 (37.5%), 3 (2%) and 2 (1.3%) patients achieved excellent, indeterminate, biochemically incomplete and structurally incomplete response, respectively. The risk of structural recurrence was similar in both groups (TgAb[-] 0.9% vs. TgAb[+] 2.4%, p = 0.46). In the TgAb(+) group, TgAb became negative in 10 (24.4%), decreased ≥ 50% without negativization in 25 (60.9%), decreased < 50% in 4 (9.8%) and remained stable or increased in 2 (4.9%) cases. The only incomplete structural response had increasing TgAb during follow-up.

CONCLUSIONS

In properly selected patients with DTC, TgAb concentration immediately after total thyroidectomy should not mandate RAI ablation, and their trend during follow-up may impact the risk of recurrence.