The Effectiveness of Radioactive Iodine Remnant Ablation for Papillary Thyroid Microcarcinoma: A Systematic Review and Meta-analysis

Lymph Node Ratio Predicts Recurrence in Patients with Papillary Thyroid Carcinoma with Low Lymph Node Yield

The American Thyroid Association risk stratification system suggests that having >5 metastatic lymph nodes (LNs) increase the recurrence risk in patients with papillary thyroid carcinoma (PTC). However, little is known about PTC with <5 harvested LNs. This study aimed to stratify patients with low-LN-yield (low-LNY) PTC based on lymph node ratios (LNRs). From 2007 to 2017, 6317 patients who underwent thyroidectomies were diagnosed with PTC at Seoul St. Mary's Hospital, and 909 patients with low LNYs were included in the study. Tumor recurrence was compared based on LNR. The LNR cutoff was determined using a receiver operating characteristic curve. Forty-six patients (5.1%) experienced recurrences over a mean follow-up period of 127.24 ± 33.6 months (range, 5-190 months). The cutoff for the low-LNR (n = 675) and high-LNR (n = 234) groups was 0.29 (AUC = 0.676, 95% CI = 0.591-0.761, p < 0.001). The recurrence rate was significantly higher in the high-LNR group compared to the rate in the low-LNR group (12.4% vs. 2.5%, p < 0.001). Multivariate analysis using Cox regression revealed that tumor size and LNR ≥ 0.29 were independent prognostic factors for recurrence. Therefore, LNR can be utilized to stratify the risk of recurrence in patients with low-LNY PTC.

Review: Improving quality of life in patients with differentiated thyroid cancer

Well differentiated thyroid cancer is a common malignancy diagnosed in young patients. The prognosis tends to be excellent, so years of survivorship is expected with low risk disease. When making treatment decisions, physicians should consider long-term quality of life outcomes when guiding patients. The implications for treating indolent, slow growing tumors are immense and warrant careful consideration for the functioning years ahead. Surgery is the standard of care for most patients, however for a subset of patients, active surveillance is appropriate. For those wishing to treat their cancer in a more active way, novel remote access approaches have emerged to avoid a cervical incision. In the era of "doing less", options have further expanded to include minimally invasive approaches, such as radiofrequency ablation that avoids an incision, time off work, a general anesthetic, and the possibility of post-treatment hypothyroidism. In this narrative review, we examine the health related quality of life effects that surgery has on patients with thyroid cancer, including some of the newer innovations that have been developed to address patient concerns. We also review the impact that less aggressive treatment has on patient care and overall wellbeing in terms of active surveillance, reduced doses of radioactive iodine (RAI) treatment, or minimally invasive techniques such as radiofrequency ablation (RFA) for low risk thyroid disease.

Radioactive Iodine Ablation Can Reduce the Structural Recurrence Rate of Intermediate-Risk Papillary Thyroid Microcarcinoma: A Meta-Analysis

Background

The incidence of papillary thyroid microcarcinoma (PTMC) has significantly increased in recent years, and the decision to use radioactive iodine (RAI) ablation in low-risk (LR) and intermediate-risk (IR) patients is controversial. The aim of this study was to evaluate whether RAI ablation can reduce the recurrence rate in LR-IR PTMC patients.

Methods

A comprehensive literature search of the PubMed, Embase, Cochrane Library, and Web of Science was conducted according to the PRISMA statement.

Results

There were 8 studies in English that fit our search strategy, and a total of 2847 patients were evaluated. The results of the meta-analysis showed RAI ablation in LR-IR PTMC patients did not reduce cancer recurrence (risk radio (RR) 0.56, 95% CI 0.19-1.70, P = 0.31). Nevertheless, we further performed data analysis and found that IR PTMC patients without RAI ablation had a higher rate of cancer recurrence than those who underwent RAI ablation (RR 0.23, 95% CI 0.11-0.49, P = 0.0001). Furthermore, patients with risk factors for lymph node metastasis (RR 0.16, 95% CI 0.06-0.42, P = 0.0002), microscopic extrathyroidal extension (RR 0.19, 95% CI 0.06-0.60, P = 0.005), and multifocality (RR 0.13, 95% CI 0.04-0.45, P = 0.001) in the absence of RAI ablation were more likely to have recurrence.

Conclusions

Based on our current evidence, RAI ablation can reduce the cancer recurrence rate over 5 years in IR PTMC patients, especially when patients have some risk factors, such as lymph node metastasis, microscopic extrathyroidal extension, and multifocality.

Differentiated thyroid carcinoma in the elderly: influence of age on disease-free and overall survival

PURPOSE

We investigated whether age at diagnosis of differentiated thyroid carcinoma (DTC) may be a risk factor for structural disease and mortality after primary treatment in aging patients.

METHODS

A multicenter, retrospective analysis including patients older than 60 years at DCT diagnosis was designed. All subjects were treated by surgery with or without radioiodine adjuvant therapy and had a minimum follow-up of one year. We compared elderly patients (group 1, 60-74 years) with very old patients (group 2, ≥75 years).

RESULTS

The study involved 1668 patients (74.3% women, median age 67 years, 87.6% papillary thyroid cancer, 73.3% treated with radioiodine), including 1397 in group 1 and 271 in group 2. Patients in group 2 had larger tumor size (1.8 [0.8-3.0] vs 1.5 [0.7-2.8] cm; P = 0.005), higher proportions of tumors with vascular invasion (23.8 vs 16.4%; P = 0.006), and lower proportion of lymphocytic thyroiditis (18.6 vs 24.9%; P = 0.013) than subjects in group 1. Kaplan-Meier survival analysis showed that patients in group 2 had significantly lower structural disease-free survival (DFS) and overall survival (OS) than patients in group 1 (P = 0.035 and <0.001, respectively). In multivariate Cox regression analysis, age was a risk factor significantly associated with OS. However, age was significantly associated with DFS in unadjusted analysis and in analysis adjusted by gender and risk classification variables, but not when pathological and therapy-related variables were introduced in the model. On the other hand, patients who received radioiodine had worse DFS (P < 0.001) compared to those who did not.

CONCLUSION

Although age is a conditioning factor for OS, very old patients do not have a greater risk of developing structural disease throughout the follow-up than elderly patients with DTC.

Risk-stratified papillary thyroid microcarcinoma: post-operative management and treatment outcome in a single center

PURPOSE

This article aims to review and assess the post-operative management and treatment outcomes of papillary thyroid microcarcinoma (PTMC) in risk-stratified patients.

METHODS

We retrospectively analyzed the data of PTMC patients who underwent thyroid surgery with or without radioactive iodine treatment (RAI) in a single center between January 2011 and December 2017. Demographic and clinicopathologic data were collected. Risk stratification according to the 2015 American Thyroid Association guideline was applied.

RESULTS

Three hundred forty PTMC patients were included. Post-operative RAI was performed in 216/340 (63.53%) patients. In the non-RAI scenario, there were 122 low-risk and two intermediate-risk patients. In total, 261 (76.77%), 57 (16.76%), and 22 (6.47%) patients were classified as low, intermediate, and high risk, respectively. With a median follow-up time of 36 months (interquartile range: 23, 52), we found unfavorable outcomes (evidenced by imaging or out-of-range serum tumor marker levels: high thyroglobulin [Tg] or rising Tg antibody [TgAb] levels) in 8/340 (2.35%) patients, all of which received RAI. PTMC patients with unfavorable outcomes were stratified as low risk (4/261 [1.53%]), intermediate risk (1/57 [1.75%]), or high risk (3/22 [13.64%]). One death occurred in a patient with initial distant metastasis in the high-risk group. Initial high-risk stratification and initial stimulated Tg (of at least 10 ng/mL) were demonstrated as independent predictors for PTMC unfavorable outcomes (persistent or recurrent disease). Five patients with unfavorable outcomes (four with persistent disease and one with recurrent disease) had abnormal Tg or TgAb values despite unremarkable imaging findings. Moreover, 79/124 (63.71%) patients in the non-RAI scenario were only followed up with neck ultrasound.

CONCLUSIONS

In general, at least 98% of low-risk and intermediate-risk PTMC patients showed favorable outcomes without persistent or recurrent disease, defined by either imaging or serum tumor markers. Nevertheless, aggressive disease could occur in few PTMC patients. Decisions on post-operative management and follow-up may be guided by initial high-risk stratification and initial stimulated Tg levels (≥10 ng/mL) as independent predictors for PTMC unfavorable outcomes. Monitoring using both imaging and serum tumor markers is crucial and should be implemented for patients with PTMC.

Predictive Factors of Recurrence of Papillary Thyroid Microcarcinomas: Analysis of 2,538 Patients

Introduction  The incidence of papillary thyroid microcarcinoma (PTMC) has increased, and its treatment remains controversial.

Objective  To identify the clinical and pathological factors predictive of tumor recurrence.

Methods  We retrospectively analyzed 2,538 consecutive patients treated for PTMC, most submitted to total thyroidectomy (98%) followed by radioactive iodine (RAI) ablation (51.7%) at a cancer center from 1996 to 2015. The patients were stratified according to the American Thyroid Association (ATA) risk categories (low, intermediate, or high), and the clinicopathological features were evaluated by multivariate Cox regression analysis to identify independent prognostic factors for recurrence.

Results  After a mean follow-up of 58 months (range: 3 to 236.5 months), tumor recurrence was diagnosed in 63 (2.5%) patients, mostly in the lymph nodes. Distant metastasis occurred in 2 (0.1%) patients. There were no cancer-related deaths. The multivariate analysis showed that age < 55 years ( p  = 0.049; hazard ratio [HR]: 2.54; 95% confidence interval [95%CI]: 0.95 to 0.99), multifocality ( p  = 0.032; HR: 1.76; 95%CI: 1.05 to 2.96), and the presence of lymph-node metastasis ( p  < 0.001; HR: 3.69; 95%CI: 2.07–6.57) were independent risk factors for recurrence. Recurrence was observed in 29 (1.5%) out of 1,940 low-risk patients, 32 (5.4%) out of 590 intermediate-risk patients, and in 2 (25%) out of 8 high-risk patients.

Conclusions  The prognosis of PTMC is excellent, favoring a conservative treatment for most patients. Age < 55 years, multifocality, and node metastasis at diagnosis, as well the ATA staging system effectively predict the risk of recurrence. The presence of these risk factors can help identify patients who should be considered for more aggressive management and more frequent follow-up.

Patient Perspectives on the Extent of Surgery and Radioactive Iodine Treatment for Low-Risk Differentiated Thyroid Cancer

OBJECTIVE

To understand patient perspective regarding recommended changes in the 2015 American Thyroid Association (ATA) guidelines. Specifically, in regard to active surveillance (AS) of some small differentiated thyroid cancer (DTC), performance of less extensive surgery for low-risk DTC, and more selective administration of radioactive iodine (RAI).

METHODS

An online survey was disseminated to thyroid cancer patient advocacy organizations and members of the ATA to distribute to the patients. Data were collected on demographic and treatment information, and patient experience with DTC. Patients were asked "what if" scenarios on core topics, including AS, extent of surgery, and indications for RAI.

RESULTS

Survey responses were analyzed from 1546 patients with DTC: 1478 (96%) had a total thyroidectomy, and 1167 (76%) underwent RAI. If there was no change in the overall cancer outcome, 606 (39%) of respondents would have considered lobectomy over total thyroidectomy, 536 (35%) would have opted for AS, and 638 (41%) would have chosen to forego RAI. Moreover, (774/1217) 64% of respondents wanted more time with their clinicians when making decisions about the extent of surgery. A total of 621/1167 of patients experienced significant side effects with RAI, and 351/1167 of patients felt that the risks of treatment were not well explained. 1237/1546 (80%) of patients felt that AS would not be overly burdensome, and quality of life was the main reason cited for choosing AS.

CONCLUSION

Patient perspective regarding choice in the management of low-risk DTC varies widely, and a large proportion of DTC patients would change aspects of their care if oncologic outcomes were equivalent.

Recurrence-free survival after total thyroidectomy and lobectomy in patients with papillary thyroid microcarcinoma

PURPOSE

The incidence of papillary thyroid microcarcinoma is increasing. We evaluated the recurrence-free survival following total thyroidectomy and lobectomy to identify the optimal surgical choice.

METHODS

A meta-analysis was performed using the National Library of Medicine and the National Institutes of Health PubMed database to identify eligible studies. Summary 5- and 10-year RFS estimates after TT versus LT were calculated using random effects models.

RESULTS

The literature search yielded 1117 studies (1990-2019). Nine studies met the inclusion criteria comprising 10,186 total thyroidectomy and 11,408 lobectomy patients. The 5-year recurrence-free survival was 98% [95% confidence interval (CI) 97-99%] after total thyroidectomy and 97% (95% CI 96-99%) after lobectomy, based on eight studies (9421 total thyroidectomy and 11,283 lobectomy patients); the 10-year recurrence-free survival was 95% (95% CI 92-98%) after total thyroidectomy and 92% (95% CI 86-96%) after lobectomy, based on eight studies (total thyroidectomy = 10,100, lobectomy = 11,389 patients).

CONCLUSION

The present meta-analysis demonstrates excellent, long-term recurrence-free survival following both total thyroidectomy and lobectomy surgery in patients with papillary thyroid microcarcinoma. The analysis also suggests that patients undergoing total thyroidectomy trended toward a slightly better long-term 10-year recurrence-free survival in comparison to patients undergoing lobectomy, a finding of potential, clinical significance in the management decision-making process.

Does the ATA Risk Stratification Apply to Patients with Papillary Thyroid Microcarcinoma?

BACKGROUND

The incidence of papillary thyroid microcarcinoma (PTMC) has increased over the past decade. The American Thyroid Association (ATA) suggests that these patients may undergo either thyroid lobectomy or active surveillance. It remains unclear whether there exists a subgroup of PTMC patients who may benefit from more aggressive treatment due to increased risk of recurrence.

METHODS

We retrospectively reviewed 357 patients with PTMC who underwent surgery at a single institution from 2004 to 2016. Patients were classified according to 2015 ATA risk stratification for structural disease recurrence. Demographic, oncologic, and clinicopathologic data were compared between groups.

RESULTS

Out of 357 patients, 246 were classified as low-risk PTMC, 93 were intermediate-risk, and 18 were high-risk. There were more male patients in the high-risk group (38.9%) than the intermediate- (31.2%) or low-risk groups (15.4%) (p < 0.001). Patients with low-risk microcarcinomas were more likely to have an incidental PTMC when compared to intermediate- or high-risk groups (98[39.8%], 15[16.1%], 1[5.6%], respectively, p < 0.001). Patients with high-risk PTMCs, compared to those with intermediate- and low-risk PTMCs, were more likely to have rising postoperative thyroglobulin levels after total thyroidectomy (6[40.0%], 4[5.1%], 9[5.7%], respectively, p = 0.001) and structural recurrence after lobectomy or total thyroidectomy (3[16.7%], 0[0%], 0[0%], respectively, p < 0.001). The median follow-up time was 17.5 (IQR 3-55) months.

CONCLUSIONS

Patients with high-risk PTMC have an increased risk of recurrence when compared to low- and intermediate-risk microcarcinomas, whereas intermediate-risk PTMC may behave similarly to low-risk tumors. ATA risk stratification may inform clinical decision making for patients with PTMC.

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.

Is Less More? A Microsimulation Model Comparing Cost-effectiveness of the Revised American Thyroid Association's 2015 to 2009 Guidelines for the Management of Patients With Thyroid Nodules and Differentiated Thyroid Cancer

OBJECTIVE

To assess relative clinical and economic performance of the revised American Thyroid Association (ATA) thyroid cancer guidelines compared to current standard of care.

BACKGROUND

Diagnosis of thyroid cancer in the United States has tripled whereas mortality has only marginally increased. Most patients present with small papillary carcinomas and have historically received at least a total thyroidectomy as a treatment. In 2015, the ATA released the revised guidelines recommending an option for active surveillance (AS) of small papillary thyroid carcinoma and thyroid lobectomy for larger unifocal tumors.

METHODS

We created a Markov microsimulation model to evaluate the performance of the ATA's 2015 guidelines compared to the ATA's 2009 guidelines. We modeled a cohort of simulated patients with demographic and thyroid nodule characteristics representative of those presenting clinically in the United States. Outcome measures include life expectancy, quality-adjusted life years, costs, and frequency of surgical adverse events.

RESULTS

In our base case analysis, the ATA 2015 strategy dominates the ATA 2009 strategy. The ATA 2015 strategy delivers greater discounted average quality-adjusted life years (13.09 vs 12.43) at a lower discounted average cost ($14,752 vs $20,126). Deaths due to thyroid cancer under the 2015 strategy are higher than the 2009 strategy but this is offset by a reduction in surgical deaths, leading to greater average life expectancy under the ATA 2015 strategy. The optimal strategy is sensitive to patients who experience a greater decrement in quality of life while undergoing AS.

CONCLUSIONS

The ATA 2015 Guidelines represent a cost-effective strategy regarding AS and extent of surgery.

Impact of prophylactic unilateral central neck dissection needed for patients with papillary thyroid microcarcinoma

Background

Papillary thyroid microcarcinoma (PTMC), the increase in the diagnosis of which has led to an overall rise in the diagnostic rate of thyroid malignancies, is generally managed through a reduction in the surgical extent. Nevertheless, a considerable number of patients with PTMC experience subclinical central lymph node (LN) metastases following prophylactic central neck dissection (CND). This study aimed to investigate the impact of prophylactic CND on locoregional recurrence in PTMC patients who underwent hemithyroidectomy.

Methods

We reviewed the medical records of 1,071 patients with clinically LN-negative PTMC who underwent hemithyroidectomy between 2004 and 2012. Cox proportional hazards regression analysis was performed to investigate the predictive factors for recurrence. The median follow-up duration was 79 months (range, 12-176 months).

Results

Totally, 613 patients underwent hemithyroidectomy only, whereas 458 underwent hemithyroidectomy plus prophylactic unilateral CND. Recurrence was observed in 27 patients (eight and 19 patients in the prophylactic and non-prophylactic CND groups, respectively). Patients with a tumor size ≤6 mm (hazard ratio, 2.927; 95% confidence interval, 1.372-6.245; P=0.005) had favorable recurrence-free survival (RFS); however, there was no relationship between prophylactic unilateral CND and RFS.

Conclusions

The incidence of locoregional recurrence was low in patients with PTMC who underwent hemithyroidectomy. In addition, prophylactic unilateral CND performance was not associated with RFS in PTMC. Accordingly, the use of prophylactic unilateral CND for clinically LN-negative PTMC should be avoided.

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.

Papillary microcarcinoma of the thyroid gland: current controversies and management

PURPOSE OF REVIEW

To highlight recent advances in our understanding of the nature of micropapillary thyroid carcinoma (mPTC), its evaluation and options of management based on risk.

RECENT FINDINGS

A dramatic increase of the incidence of papillary thyroid carcinoma has been reported worldwide during recent decades, specifically those smaller than 10 mm (mPTC). Although not taking into consideration other risk factors for aggressiveness when describing tumours by their size, most of these newly diagnosed mPTC are indolent and active surveillance can be considered as valid option for their management.

SUMMARY

An increasing number of patients with mPTC will be encountered in clinical practice. Although it is difficult to assess the aggressiveness of a tumour on size criteria, less than a total thyroidectomy and active surveillance can be considered for the majority of patients with mPTC. Further trials should be performed to prove this as a valid option of management in the majority of these patients.

Clinicopathological characteristics and recurrence risk of papillary thyroid microcarcinoma in the elderly

Background: The optimal management for elderly patients with papillary thyroid microcarcinoma (PTMC) is not well established. The aim of the present study is to describe the clinicopathological characteristics and identify predictors of recurrence in the elderly PTMC patients.

Methods: We conducted a retrospective study of PTMC patients who underwent thyroidectomy. The clinicopathological characteristics were compared between patients with age ≥65 years and <65 years. The independent predictors of recurrence were identified by multivariate Cox regression analysis.

Results: The patients in elderly group were more likely to exhibit bilaterality (P<0.050), extrathyroidal extension (P < 0.001), and central compartment lymph node metastasis (CLNM) (P<0.010), especially the ratio of CLNM >0.5 (P<0.010), than the patients with age <65 years. The elderly patients had poorer recurrence-free survival (RFS) than those with younger ages (P=0.002). Multivariate analysis indicated tumor size >5 mm (P=0.009) and CLNM ratio >0.5 (P=0.002) were independent risk factors for recurrence of the elderly patients with PTMC.

Conclusions: The elderly PTMC patients have more aggressive biological characteristics and higher recurrence rate. More aggressive treatment and rigorous follow-up could be considered for elderly patients with tumor diameter >5 mm and CLNM ratio >0.5.

Management of Papillary Thyroid Microcarcinoma

The worldwide incidence of thyroid cancer is increasing. A third of new thyroid cancer cases are papillary thyroid microcarcinoma (PTM), which are 1 cm or less. These tumors are mostly indolent with excellent prognosis. Although thyroid surgery is the most common management option for patients with PTM, new management options demand that treatment decisions must be individualized and based on patient's preference, context, and biology. This article describes management options for PTM patients and shared decision-making as a novel method for individualizing care.

Predictive Factors of Recurrence for Multifocal Papillary Thyroid Microcarcinoma With Brafv600e Mutation: A Single Center Study of 1,207 Chinese Patients

Background: The American Thyroid Association (ATA) guidelines risk stratify Braf^v600e mutated multifocal papillary thyroid microcarcinoma (BMPTMC) into different recurrence risk groups by the extent of extrathyroidal extension (ETE). These findings and modifications for BMPTMC need to be verified in additional studies. Methods: A retrospective cohort study was conducted in BMPTMC patients who underwent total thyroidectomy (TT) and central lymph node dissection (CLND) from 2008 to 2013. Overall, 1,207 patients were included, and predictive factors were identified by univariate and multivariate analysis over a mean 7.5-year follow up. Results: BMPTMC with ETE to capsule shows the same recurrence rate (3.8%) with intrathyroidal BMPTMC. Moreover, BMPTMC with ETE only to strap muscle, which belongs to high-risk group according to ATA guideline, shows relatively lower recurrence rate (13.3%) compared with some intermediate risk categories such as cN1 and >5 pN1. Multivariate analysis using a Cox proportional hazards regression model shows that total tumor diameter (TTD) is associated with significantly higher recurrence for BMPTMC with or without other risk factors (Hazard Ratio (HRO) = 9.86 [95%CI 5.35-18.20], p = 0.00; HRO = 2.32 [95%CI 1.12-4.85], p = 0.02; respectively), while Hashimoto thyroiditis (HT) is found to be protective against the recurrence (HRO = 0.51 [95%CI 0.33-0.79], p = 0.00; HRO = 0.47 [95%CI 0.25-0.89], p = 0.02; respectively). Conclusions: Taken together, capsular ETE and gross ETE to the strap muscles did not have the expected significant influence on recurrence for Chinese BMPTMC patients who underwent TT and CLND. Rather than the extent of ETE, TTD and the lack of HT were identified as predictors for recurrence among BMPTMC with or without other risk factors (vascular invasion, cN1, pN1>5, pN1>3 cm).

Radioactive Iodine Ablation Decrease Recurrences in Papillary Thyroid Microcarcinoma with Lateral Lymph Node Metastasis in Chinese Patients

Introduction

We aimed to carry out a retrospective study from a single institution to determine whether radioactive iodine (RAI) ablation decreases the risk of recurrence of papillary thyroid microcarcinoma (PTMC) patients that presented with lateral lymph node metastasis (LLNM).

Methods

We retrospectively analyzed a total of 6361 consecutive PTMC patients who initially underwent surgery for the treatment of thyroid carcinoma at the First Hospital of Jilin University, between January 2005 and February 2015. Altogether, 137 patients with PTMC with LLNM have been enrolled in our study.

Results

The disease-free survival period was significantly shorter for the RAI (−) patients than for the RAI (+) patients (p = 0.0074 by the log-rank test). The disease-free survival rates at 5 and 10 years were 93.02 and 87.5%, respectively, in the RAI (−) group and 100 and 96.81%, respectively, in the RAI (+) group. CLNM ratio and LLNM ratio were factors identified for multivariate analysis by Cox’s proportional hazards method yielding risk ratios of 7.281 [CI 1.804–17.554; p = 0.010] and 1.157 [CI 1.0125–9.381; p = 0.048] in the RAI (−) group.

Conclusion

Taken together, RAI may be beneficial for PTMC with LLNM, especially when CLNM ratio or LLNM ratio was greater than 0.5.

A meta-analysis on the effect of operation modes on the recurrence of papillary thyroid microcarcinoma

Whether total thyroidectomy reduces the recurrence rate in patients with papillary thyroid microcarcinoma (PTMC) is currently controversy. Conclusions of sporadic, inconsistent, and mono-institutional studies need a meta-analysis to evaluate. 525 relevant studies were obtained from initial search on PubMed, 511 studies were excluded by inclusion and exclusion criteria. Eligible data were extracted from each included study. The Odds ratios (ORs) and 95% confidence interval (CI) were used to assess the difference in the recurrence rates between PTMC patients treated with total thyroidectomy and non-total thyroidectomy. OR and 95% CI were calculated using a fixed-effects or a random-effects model. The Q statistic was used to evaluate homogeneity and Beggs test was used to assess publication bias. 14 studies meeting the inclusion criteria were included in this meta-analysis. The over all recurrence rates of pooled patients with total thyroidectomy and non-total thyroidectomy were 2.83% and 2.84% respectively. Primary random-effects model analysis showed, no significant difference of recurrence rates existed between two operation modes (OR = 0.732, 95% CI: 0.444 - 1.208), while, high heterogeneity among studies was found, I-squared index (I2) = 40.2%. After remove one study with high heterogeneity, the OR of the pooled recurrence rates of the total thyroidectomy and the non-total thyroidectomy groups was 0.786 (95% CI: 0.363 - 1.701), further suggesting no significant difference of the recurrence rate exists between two operation modes. Our meta-analysis demonstrated postoperative recurrence of PTMC is not reduced by total thyroidectomy, non-total thyroidectomy is also a good choice to treat PTMC patients.