Long-term outcomes of lobectomy for papillary thyroid carcinoma with high-risk features

The 2024 revised clinical guidelines on the management of thyroid tumors by the Japan Association of Endocrine Surgery

The Japan Association of Endocrine Surgery published the first edition of the "Clinical guidelines on the management of thyroid tumors" in 2010 and the revised edition in 2018. The guideline presented herein is the English translation of the revised third edition, issued in 2024. The aim is to enhance health outcomes for patients suffering from thyroid tumors by facilitating evidence-based shared decision-making between healthcare providers and patients, as well as standardizing the management of thyroid tumors. The focus is on adult patients with thyroid tumors, addressing clinically significant issues categorized into areas such as an overview of the diagnosis and treatment of thyroid nodules, treatment strategies by histological type, radioactive iodine therapy, treatment of advanced differentiated carcinoma, pharmacotherapy, and complications and safety management associated with thyroid surgery. Thirty-two clinical questions were established in these areas. Following a comprehensive search of the literature and systematic review to evaluate the overall evidence, we aimed to present optimal recommendations by considering the balance of benefits and harms from the patient's perspective. We integrated evidence and clinical experience to determine the "Certainty of evidence" and "Strength of recommendations". Based on these, we illustrated overall flows of care as "Clinical algorithms". Necessary background knowledge of diseases and established clinical procedures for understanding the recommendations are presented in "Notes", while information that may be clinically useful but for which evidence remains insufficient is included in "Columns", based on the current state of evidence. Finally, future challenges for the next revision are presented as "Future research questions".

Total thyroidectomy does not improve survival for all patients with unilateral papillary thyroid cancer exceeding 4 ​cm

BACKGROUND

Total thyroidectomy (TT) is recommended for papillary thyroid cancer (PTC) over 4 ​cm, but its universal benefit is uncertain. This study evaluates whether TT offers a significant advantage over lobectomy (LT) in improving overall survival (OS) and cancer-specific survival (CSS) for patients with unilateral PTC exceeding 4 ​cm.

METHODS

The study included 8862 patients from the Surveillance, Epidemiology, and End Results (SEER) database (2004-2021) with unilateral PTC larger than 4 ​cm. The relationship between age and survival was assessed using the restricted cubic splines (RCS) model. The effects of LT and TT on OS and CSS across age groups were analyzed using Cox regression and Kaplan-Meier (KM) methods, with and without age stratification. Propensity score matching (PSM) and sensitivity analyses were conducted to assess the robustness of the results.

RESULTS

TT did not improve OS (P ​= ​0.888) or CSS (P ​= ​0.907) compared to LT in the overall cohort. However, TT significantly improved OS (HR ​= ​0.54, P ​= ​0.004) and CSS (HR ​= ​0.55, P ​= ​0.018) in high-risk patients (T4, N1, or M1 stage), but not in low-risk patients. Age-stratified analysis showed TT benefited only young (18-55 years) high-risk patients, enhancing OS (HR ​= ​0.29, P ​= ​0.001) and CSS (HR ​= ​0.35, P ​= ​0.035). Older patients did not gain significant survival advantages from TT, regardless of risk status. These results were consistent in the PSM and sensitivity analyses.

CONCLUSIONS

TT may not be the best approach for all unilateral PTC patients over 4 ​cm in terms of OS and CSS. It improves survival outcomes in young patients with advanced TNM stages but does not confer a significant OS or CSS advantage over LT for older or low-risk patients.

Pediatric Papillary Thyroid Carcinoma: Outcomes After Surgery Without Adjuvant Radioactive Iodine

CONTEXT

Pediatric papillary thyroid carcinoma (PTC) is usually treated with total thyroidectomy followed by radioactive iodine (RAI). Recently, RAI has been used more selectively based on surgical pathology and postoperative dynamic risk stratification (DRS).

OBJECTIVE

To describe patients with pediatric PTC not initially treated with RAI and their disease outcomes.

METHODS

This was an ambispective study at a tertiary cancer center of patients < 19 years diagnosed from January 1, 1990, to December 31, 2021, with stage 1 PTC who intentionally were not treated with RAI within a year of diagnosis. We assessed clinical characteristics, management, and disease outcomes using DRS.

RESULTS

Of 490 PTC patients, we identified 93 eligible patients (median age at diagnosis 16 years; 87% female), including 46 (49%) with cervical lymph node metastases. Initial management included total thyroidectomy ± neck dissection (n = 69, 75%), lobectomy ± neck dissection (n = 20, 21%), or a Sistrunk procedure for ectopic PTC (n = 4, 4%). After a median follow-up of 5.5 years (range 1-26), most patients (85/93; 91%) remained disease-free with no further therapy. Persistent (n = 5) or recurrent (n = 3) disease was found in 9% of the entire cohort. Four patients ultimately received RAI, of which only 1 clearly benefitted, and additional surgery was performed or planned in 4 patients, 2 of whom had an excellent response at last follow-up.

CONCLUSION

Selected pediatric PTC patients, even those with lymph node metastases, may not require therapeutic 131I and can avoid the unnecessary risks of RAI while still benefitting from the excellent long-term outcomes that are well described for this disease.

Nomograms to predict occult contralateral central lymph node metastases in unilateral papillary thyroid carcinoma with ipsilateral clinical lymph node metastasis

BACKGROUND

No significant difference in disease-specific survival and recurrence-free survival exists between papillary thyroid cancer (PTC) patients with high-risk features subjected to lobectomy and thyroidectomy. However, it is unclear which type of patients with unilateral PTC combined with ipsilateral clinical involved lymph nodes (cN1) can receive a less aggressive treatment.

METHODS

We collected the medical records of 631 patients diagnosed with unilateral PTC and ipsilateral cN1. These patients initially underwent total thyroidectomy and bilateral central lymph node dissection (LND), with or without lateral LND. We conducted an analysis to investigate the associations between contralateral occult central lymph node metastasis (CLNM) and clinicopathologic factors.

RESULTS

The proportion of contralateral occult CLNM was 38.9 %. Age ≤45 years, tumor diameter >1 cm, obesity, and involvement of lymph node regions ≥2 were independent risk factors for contralateral occult CLNM. Multifocality and ipsilateral neck high-volume lymph node metastases were independent risk factors among the postoperative pathological factors. A predicting model was developed to quantify the risk of each factor, which revealed that patients without any of the risk factors mentioned above had a 20-30 % probability of contralateral occult CLNM, whereas the probability was greater than 60 % when all factors were present.

CONCLUSION

Based on the predictive nomograms, we proposed a risk stratification scheme based on different nomogram scores. In the debate about prophylactic central LND among contralateral central lymph node in unilateral PTC with ipsilateral clinical LNM, our nomograms provide the balance to avoid overtreatment and undertreatment through personal risk assessment.

Psychological impacts of lobectomy and total thyroidectomy in PTC measuring 1 to 4 cm with low to intermediate risk of recurrence

PURPOSE

To investigate the implications of Lobectomy (LT) or total thyroidectomy (TT) on psychological distress and sleep quality in PTC patients with a low to intermediate risk of recurrence and tumors measuring 1 to 4 cm.

METHODS

Patients who were admitted to our hospital between July 2021 and July 2022 were prospectively enrolled in this survey. Psychological distress and sleep quality were assessed at hospitalization, discharge, and 1, 3, and 6 months post-treatment using validated scales. Participants were divided into LT and TT groups, with propensity score matching (PSM) applied for analyses.

RESULTS

Among 525 eligible PTC patients, 440 patients completed all the questionnaires throughout the follow-up. After PSM, 166 patients underwent LT, and 166 patients underwent TT were enrolled. The psychological distress and sleep quality of patients in the LT group remained relatively stable during the 6-month follow-up, but patients in the TT group may have faced greater sleep quality concerns in the longitudinal assessment. Additionally, the sleep quality of the TT group was also worse than that of the LT group postoperatively.

CONCLUSIONS

The sleep quality rather than other psychological distress of patients with PTC with a low to intermediate risk of recurrence is associated with the extent of surgery.

Long-term efficacy of lobectomy for stage T1 papillary thyroid carcinoma with varying degrees of lymph node metastasis

Background

The presence of lymph node metastasis (LNM) is frequently observed in papillary thyroid carcinoma (PTC), and most clinical guidelines recommend total thyroidectomy. However, the impact of LNM on specific types of locoregional recurrence remains uncertain, particularly for stage T1 PTC.

Methods

The present retrospective cohort study enrolled patients diagnosed with stage T1 PTC between 2008 and 2015. Propensity score matching was performed in patients with lobectomy accompanied by varying degrees of LNM. Logistic regression analysis was performed to compare the effect of LNM on relapse types, and Kaplan-Meier method was utilized to calculate recurrence-free survival.

Results

The study cohort comprised 2,785 patients who were followed up for an average duration of 69 months. After controlling follow-up time and potential prognostic factors, we include a total of 362 patients in each group. Recurrence rates in the N0, N1a, and N1b groups were found to be 2.5%, 9.7%, and 10.2% respectively. Notably, group N1a versus group N0 (P=0.803), N1b group versus N0 group (P=0.465), and group N1b versus group N1a (P=0.344) had no difference in residual thyroid recurrence. However, when considering lymph node recurrence, both N1a(P=0.003) and N1b(P=0.009) groups showed a higher risk than N0 group. In addition, there was no difference in lymph node recurrence between N1b group and N1a group (P=0.364), but positive lymph node (PLN) and lymph node positive rate (LNPR) demonstrated a strong discriminatory effect (P<0.001).

Conclusion

Lobectomy may be more appropriate for patients with unilateral stage T1 PTC in the low LNPR group.

The preferred surgical choice for intermediate-risk papillary thyroid cancer: total thyroidectomy or lobectomy? A systematic review and meta-analysis

BACKGROUND

The optimal surgical approach for intermediate-risk papillary thyroid carcinoma (IR-PTC) (according to ATA definition), whether total thyroidectomy (TT) or lobectomy (LT), has remained a contentious clinical gray area for several decades. This systematic review and meta-analysis aim to provide robust evidence and address this clinical dilemma comprehensively.

MATERIALS AND METHODS

A comprehensive literature search was conducted in Pubmed, Embase, Web of Science, and the Cochrane Library from 1st January 2009 to 29th December 2023 to evaluate the impact of different surgical options (TT or LT) on patients with IR-PTC. The primary outcomes included survival, recurrence rates, and postoperative complications. I2 and sensitivity analysis was used to explore the heterogeneity.

RESULTS

A total of 8 studies involving 2984 participants were included in this meta-analysis and systematic review. The results indicated that LT was a superior choice for mitigating complications compared to TT [risk ratio (RR), 0.32; 95% CI: 0.24-0.44, P <0.01], particularly for transient complications (RR, 0.24; 95% CI: 0.08-0.65, P <0.01), such as the transient parathyroid dysfunction (RR, 0.04; 95% CI: 0.01-0.15, P <0.01). However, TT did not increase the risk of recurrent laryngeal nerve palsy (RR, 0.78; 95% CI: 0.24-2.47, P =0.67), hemorrhage/seroma (RR, 0.77; 95% CI: 0.48-1.25, P =0.30), and permanent complications (RR, 0.18; 95% CI: 0.02-1.42, P =0.10). Besides, both LT and TT presented similar effect on survival outcomes (overall survival: RR, 1.00; 95% CI: 0.97-1.03, P =0.92, disease-specific survival: RR, 0.99; 95% CI: 0.97-1.02, P =0.69, recurrence-free survival: RR, 1.00; 95% CI: 0.96-1.05, P =0.86), recurrence (RR, 1.05; 95% CI: 0.76-1.46, P =0.76).

CONCLUSION

The present meta-analysis revealed that TT did not yield improved outcomes in IR-PTC patients, but was associated with an increased incidence of temporary complications. In light of these findings, it may be advisable to consider LT as the optimal choice for IR-PTC patients.

Long-Term Outcomes After Lobectomy for Patients with High-Risk Papillary Thyroid Carcinoma

BACKGROUND

Guidelines universally recommend total thyroidectomy for high-risk papillary thyroid carcinoma (PTC). However, in Japan, thyroid-conserving surgery had been widely applied for such patients until recently. We investigated long-term outcomes for this strategy.

METHODS

A prospectively recorded database was retrospectively analyzed for 368 patients who had undergone curative surgery for high-risk PTC without distant metastasis between 1993 and 2013. High-risk PTC was defined for tumors showing tumor size > 4 cm, extrathyroidal extension, or large nodal metastasis ≥ 3 cm.

RESULTS

Median age was 59 years and 243 patients were female. Mean duration of follow-up was 12.7 years. Lobectomy was conducted for 207 patients (LT group) and total or near-total thyroidectomy for 161 patients (TT group). The frequency of massive extrathyroidal invasion and large nodal metastasis was lower in the LT group than in the TT group. After propensity score matching, no significant differences were seen between groups for overall survival, cause-specific survival or distant recurrence-free survival. In the overall cohort, multivariate analysis identified age ≥ 55 years, large nodal metastasis, tumor size > 4 cm and massive extrathyroidal invasion as significantly associated with cause-specific survival, whereas extent of thyroidectomy was not.

CONCLUSIONS

For patients with high-risk PTC without distant metastasis, curative surgery with lobectomy showed almost identical oncological outcomes compared to total thyroidectomy. The benefits of total thyroidectomy for high-risk PTC should be reevaluated in the future prospective studies.

Comparison of Lobectomy vs Total Thyroidectomy for Intermediate-Risk Papillary Thyroid Carcinoma With Lymph Node Metastasis

Importance

Surgical treatment of patients with papillary thyroid cancer (PTC) by either lobectomy or total thyroidectomy (TT) has long been a topic of debate, especially for patients with intermediate-risk PTC.

Objective

To compare recurrence-free survival (RFS) for patients with PTC and lymph node metastasis after lobectomy vs TT.

Design, Setting, and Participants

This retrospective cohort study included a review of patients with PTC treated from January 1, 2000, to December 31, 2017. Propensity score matching (PSM) was performed between patients treated with lobectomy and TT. This study involved a single institute in a cancer referral center. Enrolled were adult patients (aged 18-75 years) with unilateral PTC and ipsilateral clinical lateral neck metastasis (cN1b). Patients with the following characteristics were excluded: a lymph node yield less than 20, primary tumor size greater than 4 cm, gross extrathyroidal extension, metastatic lymph node size greater than 3 cm, and distant metastasis. Data analysis was performed from April 1 to April 30, 2022.

Exposures

Lobectomy and TT.

Main Outcomes and Measures

The primary outcome was the association between extent of surgery and RFS, assessed using Cox proportional hazards regression models.

Results

A total of 946 patients with PTC (mean [SD] age, 37.0 [12.1] years, 630 female individuals [66.6%]) were analyzed. Lobectomy (624 [66.0%]) was negatively correlated with the frequencies of older age (≥65 years, 17 [2.7%]), female sex (393 [63.0%]), multifocality (132 [21.2%]), minor extrathyroidal extension (259 [41.5%]), number of metastatic lymph nodes (median [range], 9 [6-14] nodes), and radioactive iodine ablation (0). After PSM with treatment period and potential prognostic factors (age, sex, primary tumor size, multifocality, minor extrathyroidal extension, number of lymph node metastases and lymph node ratio), 265 pairs of patients were available for analysis. After a median (range) follow-up of 60 (9-150) months in the lobectomy group and 58 (8-161) months in the TT group, 21 (7.9%) and 17 (6.4%) structural recurrences were identified in the lobectomy and TT groups, respectively. Lobectomy was not associated with significantly compromised 5-year RFS rate (lobectomy, 92.3% vs TT, 93.7%; adjusted hazard ratio, 1.10; 95% CI, 0.58-2.11; P = .77). Power analysis indicated that the test had 90% power to detect a more than 4.9% RFS difference. No significant difference in RFS was observed between patients treated with TT and radioactive iodine ablation (n = 75) and their counterparts (adjusted hazard ratio, 0.59; 95% CI, 0.14-2.41; P = .46).

Conclusions and Relevance

Results of this cohort study suggest that patients with PTC and lymph node metastasis had a similar RFS after lobectomy vs those who had TT. If radioactive iodine ablation is not going to be performed, lobectomy may be an effective alternative option.

Less-Intensive Management Options for Low-Risk Thyroid Cancer

The incidence of thyroid cancer is increasing, whereas mortality remains relatively stable. An increasing body of research supports the use of less-intensive treatment for low-risk thyroid cancer, as the overall prognosis is excellent. Although total thyroidectomy was the gold standard for many years, the options of lobectomy alone, active surveillance, and other ablative modalities are increasingly being used. The clinicohistologic features of any thyroid cancer are important to help determine the optimal management for a given tumor. However, the patient's own desires and goals in their cancer treatment must be evaluated.

Optimal Serum Thyrotropin Level for Patients with Papillary Thyroid Carcinoma After Lobectomy

Background: The optimal serum thyrotropin (TSH) level for postlobectomy papillary thyroid carcinoma (PTC) patients is unclear. The objective of this study was to examine the association of TSH and recurrence in postlobectomy patients. Methods: Patients who underwent lobectomy for PTC in a single tertiary hospital from January 2000 to December 2014 were enrolled. The mean TSH of a patient was calculated based on each serum TSH value during follow-up. The reference range of serum TSH was 0.5-4.0 mU/L. Univariate and multivariable analyses were performed with Cox proportional hazards models. Restricted cubic spline (RCS) functions were used to model relationships between mean TSH and recurrence-free survival (RFS). Results: A total of 2297 patients (median age 42 years; 1750 (76.2%) female) were analyzed. Mean TSH below (≤0.5mU/L), in the lower half (0.6-2 mU/L), in the upper half (2.1-4 mU/L), and above (>4 mU/L) the reference range were observed in 668 (29.1%), 1162 (50.6%), 345 (15.0%), and 122 (5.3%) patients, respectively. According to the Cox model and RCS, no association was observed between mean TSH and RFS in the whole cohort, low-risk group and intermediate- to high-risk groups (adjusted p = 0.4737, 0.9314, 0.1859, adjusted p for nonlinear = 0.4589, 0.8622, 0.3010). The only RFS difference observed in the stratified univariate analysis was between patients with mean TSH in the lower half (0.6-2 mU/L, n = 659) and above the reference range (>4 mU/L, n = 68) in the intermediate- to high-risk group (10-year RFS by Kaplan-Meier 84.4% vs. 69.4%, log rank p = 0.011). Conclusions: Mean serum TSH levels are not associated with recurrence. A normal TSH reference range is recommended for postlobectomy PTC patients.

Predictive Value of Serum Thyroglobulin for Structural Recurrence Following Lobectomy for Papillary Thyroid Carcinoma

Background: The value of serum thyroglobulin/antithyroglobulin (Tg/antithyroglobulin antibody [ATg]) for papillary thyroid carcinoma (PTC) surveillance after lobectomy was investigated. We aimed to examine the association between postlobectomy serum Tg/ATg and PTC structural recurrence and define applicable values for stratification. Methods: PTC patients who underwent lobectomy with adequate serum Tg/ATg data during 2000-2014 were selected. Predictive classifiers of recurrence using random forest were established combining different variables related to serum Tg (ATg-negative patients) or ATg (ATg-positive patients). Cutoff values were determined with receiver operating characteristic curves when applicable. Kaplan-Meier curve and Cox regression were performed to examine the predictive value of elevated Tg/ATg. Results: Of 1451 patients enrolled, 66 (6.3%) and 26 (6.5%) patients in the ATg-negative group (n = 1050) and ATg-positive group (n = 401) developed recurrence. The established classifier of serum Tg (n = 1050) showed a favorable association with recurrence (AUC = 0.81), while serum ATg did not (AUC = 0.72). The optimal cutoff values of the first Tg (FTg, measured 6-12 months after lobectomy) and last Tg (LTg, measured most recently) were 5.3 and 11.0 ng/mL, respectively. Elevated LTg patients had significantly higher recurrence rates than normal LTg patients (23.5% vs. 4.4%, p < 0.05). Patients with elevated FTg had significantly lower recurrence-free survival rates than patients with normal FTg in all ATg-negative patients, low-risk patients, and intermediate- to high-risk patients (according to the American Thyroid Association initial risk stratification) (n = 1050, 583, and 467, all p < 0.05). Multivariate analysis indicated patients with elevated FTg had twice the recurrent risk compared with those with normal FTg (hazard ratio = 2.052). Conclusions: Postlobectomy serum Tg has favorable value for predicting recurrence in PTC patients, and reasonable thresholds could identify patients at higher risk for recurrence during follow-up.

Prevalence of Hashimoto Thyroiditis in Adults With Papillary Thyroid Cancer and Its Association With Cancer Recurrence and Outcomes

IMPORTANCE

Hashimoto thyroiditis (HT) has been suggested to be associated with papillary thyroid cancer (PTC) development. However, its association with PTC progression remains unclear.

OBJECTIVE

To examine the association between HT and PTC presentation and outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included a review of patients aged 18 to 75 years who had pathologically confirmed PTC treated at a single center in China from January 1, 2001, to December 31, 2014. Data analysis was performed from November 1 to December 31, 2020.

EXPOSURES

Coexistent HT was defined according to evaluation of postoperative paraffin sections.

MAIN OUTCOMES AND MEASURES

The primary outcome was the association of HT with PTC-related mortality, assessed using Cox proportional hazards regression models. The secondary outcome was the association of HT with aggressive characteristics and structural recurrence of PTC, assessed using logistic regression and Cox proportional hazards regression with and without adjustment for related factors.

RESULTS

Of 9210 patients with PTC (mean [SD] age, 43.6 [12.0] years; 6872 [75%] women) included in the analysis, 1751 (19%) had HT. In the logistic regression model, HT was negatively associated with frequencies of primary tumor size of 4 cm or greater (adjusted odds ratio [aOR], 0.20; 95% CI, 0.12-0.33; P < .001), gross extrathyroidal extension (aOR, 0.44; 95% CI, 0.36-0.54; P < .001), extranodal extension (aOR, 0.66; 95% CI, 0.55-0.80; P < .001), and distant metastasis (aOR, 0.17; 95% CI, 0.04-0.71; P = .02). After a median follow-up of 85 months (range, 12-144 months), 131 PTC-related deaths were identified in the cohort; 2 patients who died had HT. Patients with HT had significantly superior outcomes compared with patients without HT in terms of unadjusted 10-year disease-specific survival (99.9% vs 96.6%; log-rank P < .001) and recurrence-free survival (92.0% vs 87.6%; log-rank P = .001). After adjusting for sex, age, primary tumor size, extrathyroidal extension, lymph node metastasis, distant metastasis, extent of surgery, and radioactive iodine ablation, HT was associated with decreased PTC-related mortality (hazard ratio [HR], 0.19; 95% CI, 0.05-0.76; P = .02). Stratified analysis showed that HT was associated with less frequent structural recurrence in patients with extrathyroidal extension (HR, 0.52; 95% CI, 0.38-0.71; P < .001; P = .002 for interaction) or after total thyroidectomy (HR, 0.50; 95% CI, 0.35-0.69; P < .001; P = .009 for interaction).

CONCLUSIONS AND RELEVANCE

In this cohort study, patients with coexistent HT had less aggressive characteristics at presentation and better outcomes of PTC than did patients without HT. The findings suggest that autoimmune thyroiditis has a protective role in association with thyroid cancer.