Completion Thyroidectomy is Less Common Following Updated 2015 American Thyroid Association Guidelines

Practice patterns in management of differentiated thyroid cancer since the 2014 British Thyroid Association (BTA) guidelines

BACKGROUND

The updated 2014 BTA guidelines emphasised a more conservative, risk adapted model for the management of low-risk differentiated thyroid cancer (DTC). In comparison to historical approach of total thyroidectomy combined with radioactive iodine, treatment de-escalation is increasingly supported.

AIMS

To evaluate the impact of the updated BTA guidelines on the management of DTC cases at regional UK centre.

METHODS

All DTC patients were retrospectively identified from regional thyroid MDT database between Jan2009-Dec2020. Oncological treatment and clinico-pathological characteristics were analysed.

RESULTS

623 DTC cases were identified; 312 (247 female: 65 male) between 2009 and 2014 and 311 (225 female: 86 male) between 2015 and 2020. Median age is 48 years (range 16-85). By comparing pre- and post-2015 cohorts, there was a significant drop in total thyroidectomy (87.1% vs 76.8%, p = 0.001) and the use of radioactive iodine (RAI) (73.1% vs 62.1%, p = 0.003) in our post-2015 cohort. When histological adverse features were analysed, extra-thyroidal extension (4.2% vs 17.0%, p=< 0.001), lymphovascular invasion (31.4% vs 50.5%, p=<0.001) and multi-centricity (26.9% vs 43.4%, p = 0.001) were significantly increased in the post 2015 cohort. Nonetheless, total thyroidectomy (TT) remains the treatment choice for low risk T1/2 N0 M0 disease in 65.3% (124/190) in post-2015 cohort for several reasons. Reasons include adverse histological features (50.8%), benign indications (32.5%), contralateral nodules (11.7%), patient preference (2.5%), and diagnostic uncertainty (2.5%).

CONCLUSION

Our study confirms a move towards a more conservative approach to patients with low-risk DTC in the UK, which is in keeping with the BTA 2014 guideline and international trends, but total thyroidectomy remains prevalent for low risk T1/2 N0 M0 disease for other reasons.

Insurance-Based Disparities in Guideline-Concordant Thyroid Cancer Care in the Era of De-Escalation

INTRODUCTION

Prior studies have demonstrated insurance-based disparities in the treatment of well-differentiated thyroid cancer. However, it remains unclear whether these disparities have persisted in the era of the 2015 American Thyroid Association (ATA) management guidelines. The goal of this study was to assess whether insurance type is associated with the receipt of guideline-concordant and timely thyroid cancer treatment in a modern cohort.

METHODS

Patients diagnosed with well-differentiated thyroid cancer between 2016 and 2019 were identified from the National Cancer Database. Appropriateness of surgical and radioactive iodine treatment (RAI) was determined based on the 2015 ATA guidelines. Multivariable logistic regression and Cox proportional hazard regression analyses, stratified at age 65, were used to evaluate the associations between insurance type and appropriateness and timeliness of the treatment.

RESULTS

125,827 patients were included (private = 71%, Medicare = 19%, Medicaid = 10%). Compared to privately insured patients, patients with Medicaid more frequently presented with tumors >4 cm in size (11% versus 8%, P < 0.001) and regional metastases (29% versus 27%, P < 0.001). However, patients with Medicaid were also less likely to undergo appropriate surgical treatment (odds ratio 0.69, P < 0.001), less likely to undergo surgery within 90 d of diagnosis (hazard ratio 0.80, P < 0.001), and more likely to be undertreated with RAI (odds ratio 1.29, P < 0.001). There were no differences in the likelihood of guideline-concordant surgical or medical treatment by insurance type in patients ≥65 y old.

CONCLUSIONS

In the era of the 2015 ATA guidelines, patients with Medicaid remain less likely to receive guideline-concordant, timely surgery and more likely to be undertreated with RAI compared to privately insured patients.

Molecular Testing Predicts Incomplete Response to Initial Therapy in Differentiated Thyroid Carcinoma without Lateral Neck or Distant Metastasis at Presentation: Retrospective Cohort Study

BACKGROUND

Molecular testing (MT) is emerging as a potential prognostic factor that can be available before treatment of differentiated thyroid carcinoma begins. Among patients eligible for either lobectomy or total thyroidectomy as their initial therapy, our study aim was to assess (1) if conventionally available preoperative factors are associated with incomplete response to initial therapy, and (2) if molecular testing (MT) results can be a surrogate for the ATA Risk Stratification System (RSS) to estimate risk of recurrence.

METHODS

The data of consecutive thyroid cancer patients without preoperative lateral neck disease or distant metastasis who underwent index thyroidectomy between November 1, 2017 and October 31, 2021 were reviewed. Logistic regression models including preoperative variables such as MT and/or the postoperatively available RSS were constructed to predict disease recurrence, either structural or biochemical. Model discrimination using the c-statistic and goodness-of-fit were compared.

RESULTS

Among 945 patients studied, 50 (5.2%) recurred with 18-month median follow up. Recurrences were detected in 17 (2.9%), 20 (6.7%), and 13 (22.8%) patients with RSS-Low, -Intermediate, and -High cancers, respectively (p<0.001). In multivariable analysis, only tumor size was associated with recurrence (OR 1.3, 95% CI 1.1-1.5). In a different model analyzing 440 (46.6%) patients with available MT results, recurrence was associated with both larger tumor size (OR 1.4, 95% CI 1.1-1.8) and MT results (p<0.001). Including MT improved the c-statistic by 27%, which was statistically no different than the model incorporating only the RSS (p=0.15).

CONCLUSIONS

Disease recurrence was observed across all ATA RSS categories in short-term follow-up, and tumor size was the only conventional preoperative factor associated with recurrence. When MT results were incorporated, they not only improved predictive ability beyond tumor size alone, but also yielded similar ability as the gold standard ATA RSS. Thus, MT results might aid the development of novel preoperative risk stratification algorithms.

Impact of completion thyroidectomy on postoperative recovery in patients with differentiated thyroid cancer

While an increasing number of patients now undergo lobectomy for low-risk differentiated thyroid cancer, a subset of patients require completion thyroidectomy to facilitate radioactive iodine therapy. Completion thyroidectomy is generally as safe as the initial operation, but a previous study showed that a longer hospitalization is required for completion thyroidectomy. In this study, we reviewed 61 consecutive patients who had been treated with an initial lobectomy and subsequent completion thyroidectomy at our institution from 2012 to 2021. We detected a changepoint in 2016 for the proportion of patients who were treated with a thyroid lobectomy (Pettitt's test P = 0.049). The rate of completion thyroidectomy remained stable throughout the study period. There was no difference in operating time, intraoperative blood loss, perioperative drop in calcium levels, and postoperative hospital stay between surgeries. The patients reported higher pain scores on the day of operation (P = 0.007) and the postoperative day 1 (P = 0.022). Occult papillary microcarcinomas were identified in the contralateral thyroid lobe in 13 (21%) patients. Multifocality was the only predictor for residual malignancy in multivariate regression. In conclusion, patients with differentiated thyroid cancer experienced more pain in the immediate postoperative period following completion thyroidectomy. Hospital stays do not change with appropriate opioid-free pain control.

Endocrine surgeons are performing more thyroid lobectomies for low-risk differentiated thyroid cancer since the 2015 ATA guidelines

BACKGROUND

The 2015 American Thyroid Association guidelines recommended either total thyroidectomy or lobectomy for surgical treatment of low-risk differentiated thyroid cancer and de-escalated recommendations for central neck dissections. The study aim was to investigate how practice patterns among endocrine surgeons have changed over time.

METHODS

All adult patients with low-risk differentiated thyroid cancers (T1-T2, N0/Nx, M0/Mx) in the Collaborative Endocrine Surgery Quality Improvement Program (2014-2021) were identified. The outcomes between patients undergoing lobectomy versus total thyroidectomy were compared using multivariable logistic regression. The annual percent change in the proportion of lobectomies and central neck dissections performed was estimated using joinpoint regression.

RESULTS

In total, 5,567 patients with low-risk differentiated thyroid cancers were identified. Of these, 2,261 (40.6%) were very low-risk tumors ≤1 cm, and 2,983 (53.6%) were low-risk tumors >1 and <4 cm. Most patients (67.9%) underwent total thyroidectomy. Compared to total thyroidectomy, lobectomy was associated with outpatient surgery (adjusted odds ratio 5.19, P < .001), a decreased risk of postoperative emergency department visits (adjusted odds ratio 0.63, P = .03), and decreased risk of hypoparathyroidism events (adjusted odds ratio 0.03, P < .001). Compared to before (2014-2015), patients undergoing surgery after publication of the revised guidelines (2016-2021) had higher odds of lobectomy and lower odds of central neck dissection for tumors ≤1 cm (lobectomy adjusted odds ratio 2.70, P < .001; central neck dissections adjusted odds ratio 0.64, P = .03) and tumors between 1 and 4 cm (lobectomy adjusted odds ratio 2.27, P < .001; central neck dissection adjusted odds ratio 0.62, P < .001).

CONCLUSION

After publication of the 2015 American Thyroid Association guidelines, there has been an increase in thyroid lobectomies as a proportion of all thyroid operations performed by endocrine surgeons for low-risk differentiated thyroid cancer. This has implications for reduced health care use and costs, with potential population-level benefits.

Management of thyroid nodules

In the past 30 years, there has been a substantial rise in the detection of thyroid nodules. Largely asymptomatic, thyroid nodules are most often incidental findings that typically pose minimal risk. Data supporting these findings show a rapid rise in the incidental detection of thyroid nodules and cancer, but minimal effect on mortality rates, despite treatment. These data imply that historical approaches to thyroid nodule and cancer care might at times include unnecessary or excessive care. To address this issue, the past decade has witnessed an increasingly conservative approach to nodule management, seeking to individualise care and provide the most focused intervention that leads to favourable outcomes. Benign nodules can be safely monitored with minimal, or long-interval follow-up imaging. Molecular testing should be considered for cytologically indeterminate nodules because of its ability to improve preoperative cancer risk determination and reduce unnecessary surgery. The treatment of biopsy-proven malignant nodules has become increasingly nuanced, since recommendations for near-total thyroidectomy are no longer routine. Hemithyroidectomy is now commonly considered when operative intervention is favoured. Some patients with small volume, isolated cancerous nodules are safely managed non-operatively with active monitoring. In summary, modern management strategies for thyroid nodular disease seek to incorporate the growing amount of available diagnostic and prognostic data, inclusive of demographic, radiological, pathological and molecular findings. Once obtained, an individualised management plan can be effectively formulated.

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.

Favorable Early Outcomes With Thyroid Lobectomy for Low-Risk Papillary Thyroid Cancer: The Mayo Clinic Experience

BACKGROUND

Until 2015, standard of care for low-risk papillary thyroid cancer (PTC) >1 cm was a total or near-total thyroidectomy. Despite changes in guidelines and surgical management of low-risk PTC since 2015, little data are available regarding the effect on the need for additional surgery or risk for development of lymph node metastases. Our aim was to determine outcomes in patients who underwent initial thyroid lobectomy for low-risk PTC at a high-volume tertiary care institution.

METHODS

Retrospective review of patients ≥18 years old with biopsy proven low-risk PTC 1-4 cm who underwent partial thyroidectomy (eg, lobectomy/isthmusectomy) at Mayo Clinic, Rochester, MN, between March 2016 and June 30, 2019.

RESULTS

From 1481 thyroidectomies performed during study period, 940 contained PTC on final pathology. Of these, 87 (of 123) patients who had an initial thyroid lobectomy met inclusion criteria. Five (6%) of these patients proceeded to completion thyroidectomy (CT), with 3 requiring CT and radioactive iodine in the first postoperative year and 2 undergoing only CT in the second postoperative year. No postoperative complications were reported. No patient in this cohort required additional surgery or treatment for newly discovered lymph node metastases during the follow-up period. 43 (of 72, 60%) patients not on thyroxine therapy preoperatively were started on thyroxine therapy postoperatively.

CONCLUSIONS

Early outcomes for those undergoing thyroid lobectomy for low-risk PTC at our institution have been favorable. These results support the 2015 American Thyroid Association guidelines to offer lobectomy for those with low-risk PTC 1-4 cm.