Postoperatively determined high-risk histopathologic features in papillary thyroid carcinoma initially eligible for thyroid lobectomy: a game changer

Reoperation Rates after Initial Thyroid Lobectomy for Patients with Thyroid Cancer: A National Cohort Study

Introduction The 2015 ATA guidelines recommended thyroid lobectomy (TL) as an alternative to total thyroidectomy (TT) for the surgical treatment of low-risk differentiated thyroid cancer. Increasing use of TL has since been reported despite concerns for an increased risk of disease recurrence and need for reoperation. This study sought to compare reoperation rates among patients who underwent initial TL or TT for malignancy, characterize trends at centers based on operative volume, and examine factors associated with reoperation. Methods We queried the Vizient Clinical Data Base for TL and TT performed pre-guideline change (pre-GC=2013-2015) and post-guideline change (post-GC=2016-2021). Reoperations included reoperative thyroid surgery (RTS) and neck dissection (ND); timing was defined as early (180 days), thought to indicate inadequacy of initial operative choice, or late (>180 days), suggesting disease recurrence. Results Of 65,627 patients, 31.8% underwent initial TL and 68.2% underwent initial TT; TL increased from 21.4% of total cases pre-GC to 37.0% post-GC (p<0.001). Among TL patients, early RTS declined from 33.9%-14.2% and ND declined from 0.8%-0.4% (p<0.001). Among TT patients, early RTS remained 0.2%, while ND increased from 0.4%-0.7% (p<0.001). TL-associated late RTS declined from 2.0%-1.7%, while ND increased from 0.6%-0.8% (p=0.17). In TT patients, both late RTS and ND increased, from 0.2%-0.3% (p=0.04) and 1.7%-2.1% (p<0.01), respectively. There was no difference in the late reoperation rate for TL compared to TT post-GC (+0.2%, p=0.18). TL volume grew annually by 12.5% [8.9%-16.2%] at high-volume centers and 8.3% [5.6%-11.1%] at low-volume centers. TL-associated reoperations at high-volume centers declined annually by 12.6% [5.6%-19.0%] and 10.8% [2.7%-18.1%] at low-volume centers. Uninsured status and more recent initial operation were associated with an increased risk of late reoperation (HR=1.84 [1.06-3.20] and HR=1.30 [1.24-1.36], respectively). The type of index operation performed, however, was not predictive of late reoperation. Conclusions The rate of early reoperations declined for thyroid lobectomy after the 2015 ATA guideline release but late reoperations remained unchanged despite a significant shift in practice patterns towards performing initial lobectomy. Patients appear to be receiving less aggressive, guideline-concordant care without a significant increase in the late reoperation rate for thyroid lobectomy compared to total thyroidectomy.

Risk staging with prophylactic unilateral central neck dissection in low-risk papillary thyroid carcinoma

OBJECTIVE

Current guidelines favor thyroid lobectomy for intrathyroidal cT1bT2cN0 papillary thyroid carcinoma. Prophylactic neck dissection (PND) is not recommended for these low-risk tumors due to the lack of high-level evidence on improvement in outcomes, but the information from PND may be used for staging. The aim of this study was to evaluate the rate of upstaging with ipsilateral PND.

MATERIALS AND METHODS

Retrospective study of patients with intrathyroidal unifocal cT1bT2cN0 papillary thyroid carcinoma from 2008 to 2021. All patients underwent total thyroidectomy and PND. Tumors were classified as low or intermediate risk based on the information from pathological analysis of the primary tumor and then from adding the analysis of the lymph nodes. The difference between the tumor-only and the PND-added risk staging was evaluated.

RESULTS

Three hundred three patients (241 women, median age 45, median tumor size 17 mm) were included. Microscopic extrathyroidal extension was found in 23.4%, aggressive histology in 6.6%, vascular invasion in 29.3%, and lymph node metastases in 37.3%. One hundred ten patients (36.3%) were intermediate-risk based on the primary tumor. An additional 26 (8.6%) were upstaged to intermediate-risk based on the ipsilateral PND and 2% based on the contralateral PND. Kaplan-Meier 10-year event-free survival in tumors upstaged with ipsilateral PND was not statistically different from intermediate-risk tumors based on the primary tumor characteristics (92% versus 90.9%, Log Rank p = 0.943).

CONCLUSIONS

Ipsilateral PND upstaged low-risk cT1bT2cN0 patients to intermediate risk in only 8.6% of cases, and contralateral PND in an additional 2%. Routinely performing PND may not be warranted.

Lobo-isthmectomy in the management of differentiated thyroid cancer

We have recently witnessed a rapid increase in the incidence of differentiated thyroid carcinoma (DTC), particularly low and very low-risk papillary thyroid carcinoma. Simultaneously, the number of cancer-related deaths has remained stable for more than 30 years. Such an indolent nature and long-term survival prompted researchers and experts to an ongoing discussion on the adequacy of DTC management to avoid, on the one hand, the overtreatment of low-risk cases and, on the other hand, the undertreatment of highly aggressive ones.The most recent guidelines of the American Thyroid Association (ATA GL) moved primary thyroid surgery in DTC towards a less aggressive approach by making lobectomy an option for patients with intrathyroidal low-risk DTC tumors up to 4 cm in diameter without evidence of extrathyroidal extension or lymph node metastases. It was one of the key changes in DTC management proposed by the ATA in 2015.Following the introduction of the 2015 ATA GL, the role of thyroid lobectomy in DTC management has slowly become increasingly important. The data coming from analyses of the large databases and retrospective studies prove that a less extensive surgical approach, even if in some reports it was related to a slight increase of the risk of recurrence, did not show a negative impact on disease-specific and overall survival in T1T2N0M0 low-risk DTC. There is no doubt that making thyroid lobectomy an option for low-risk papillary and follicular carcinomas was an essential step toward the de-escalation of treatment in thyroid carcinoma.This review summarizes the current recommendations and evidence-based data supporting the necessity of de-escalation of primary thyroid surgery in low-risk DTC. It also discusses the controversies raised by introducing new ATA guidelines and tries to resolve some open questions.

[Hemithyroidectomy or total thyroidectomy for low-risk papillary thyroid cancer? : Surgical criteria for primary and secondary choice of treatment in an interdisciplinary treatment concept]

The increase in small intrathyroid papillary thyroid cancer (PTC) observed worldwide over the past two decades, with no increase in cancer-specific mortality, has challenged the previous concept of total thyroidectomy as a one-size-fits-all panacea. After exclusion of papillary microcarcinomas, a systematic review of 20 clinical studies published since 2002, which compared hemithyroidectomy (HT) to total thyroidectomy (TT), found comparable long-term oncological outcomes for low-risk papillary thyroid cancer (LRPTC) 1-4 cm in diameter, whereas postoperative complication rates were markedly lower for HT. To refine individual treatment plans, HT should be combined with ipsilateral central lymph node dissection and intraoperative frozen section analysis for staging. Based on recent evidence from studies and in consideration of individual risk factors, patients with LRPTC can be offered the concept of HT as an alternative to the standard TT. A prerequisite for the treatment selection and decision is a comprehensive patient clarification of the possible advantages and disadvantages of both approaches.

Is thyroglobulin a reliable biomarker of differentiated thyroid cancer in patients treated by lobectomy? A systematic review and meta-analysis

OBJECTIVES

The prognostic role of thyroglobulin in predicting recurrence in differentiated thyroid cancer (DTC) patients treated by lobectomy is controversial. This systematic review with meta-analysis aimed to update the current evidence deepening the reliability of circulating thyroglobulin in assessing the early response and in predictive recurrence.

METHODS

The methodology was registered in the PROSPERO database under the protocol number CRD42021288189. A systematic search was carried out on PubMed, Embase, Web of Science, and Scopus from September to November 2021 without time and language restrictions. The literature search strategy was based on the following keywords: Thyroglobulin AND (Lobectomy OR Hemithyroidectomy).

RESULTS

After screening 273 articles, seven studies were included in the systematic review, and only six of them were included in the meta-analysis for a total of 2,455 patients. Circulating thyroglobulin was found non-reliable in assessing early response and predicting recurrence in patients with hemithyroidectomy, especially those with a low initial ATA classification.

CONCLUSIONS

Our study does not support serum thyroglobulin levels for monitoring patients with low-risk DTC treated with lobectomy, and weak evidence supports its role for intermediate- or high-risk patients. Studies with longer follow-up, different study designs, and stringent inclusion/exclusion criteria are needed to evaluate the role of thyroglobulin in recurrence prediction.