Long term outcomes of simple clinical risk stratification in management of differentiated thyroid cancer

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.

Comparison of staging and recurrence predictors in patients with differentiated thyroid cancer between the 7th and 8th editions of the American Joint Committee on Cancer staging systems

BACKGROUND

The predictive value of American Joint Committee on Cancer (AJCC) 8 for recurrence in differentiated thyroid cancer (DTC) is not known. We aimed to compare AJCC 7 and 8 regarding the differences in staging and recurrence predictors in DTC.

METHODS

Demographic, clinical (duration of disease and follow-up, the extent of surgery), laboratory (TSH, fT4, thyroglobulin, and antithyroglobulin), pathological (type of thyroid cancer, localization, multifocality, diameter, extrathyroidal extension [ETE], and lymph node [LN] metastasis), and imaging findings (sonography, and whole-body scan), and follow-up features (metastases, recurrence and/or persistence, and RAI need) were retrospectively analyzed in adult patients with DTC followed-up for at least six months. Staging was determined in accordance with AJCC 7 and AJCC 8, prediction of recurrence and persistence by ATA risk stratification, and death risk by AMES systems. The alterations in staging and recurrence predictors were analyzed.

RESULTS

A majority of study patients (N.=524) were female (N.=424) and diagnosed with papillary cancer (N.=511), the median age at diagnosis was 44. 97.89% (N.=93) of stage 2-4 patients (N.=95) in AJCC 7 were down-staged in AJCC 8. We down-staged 41 patients of 45-55 years of age into stage 1 in AJCC 8 independent of LN status. A percentage of 26.71% of patients (N.=140) did have persistence, 9.54% (N.=50) persistence at the last follow-up, and 9.54% (N.=50) had recurrence. According to AJCC 8, T4 and AMES high risk were predictors for recurrence (hazard ratio: 3.053, P=0.023; hazard ratio:2.465, and P=0.005; respectively). Both AJCC 7 and 8 were associated with recurrence (P=0.008 and P<0.001, respectively). Stage 4 in AJCC 7, and stages 3 and 4 in AJCC 8 better predicted the probability of recurrence.

CONCLUSIONS

Our findings suggest that AJCC 8 better predicted the recurrence in DTC than AJCC 7. In AJCC 8, T4 tumor, AMES high risk, stages 3 and 4 predicted recurrence. The vast majority of patients with stages 2-4 in AJCC 7 were down-staged in AJCC 8.

Clinicopathological features of Differentiated Thyroid Cancer presenting in the UK versus internationally: An observational cohort study

INTRODUCTION

Very little data are available regarding differentiated thyroid cancer (DTC) managed in the UK, and no UK patients are included in the evidence base upon which international guidelines are based. Therefore, the aim of this study was to compare the clinicopathological features of patients with DTC presenting in a UK population with international patient cohorts.

PATIENTS AND METHODS

Data were collected from a prospectively held multi-disciplinary team records from January 2009 to December 2016. The local cohort was compared with cohorts from across the world based on clinicopathological features. Ethical approval was obtained by Lothian Caldicott Guardian (Ref 16 133).

RESULTS

444 cases were diagnosed locally with a median age of 48 years (range 16-86 years). 78% of patients were female. 25% of our patients had follicular carcinoma with an overall N1 rate of 20%. Distant disease was recorded in 5% cases. In comparison with international data, our local cohort had a higher rate of follicular thyroid carcinoma. Variation was seen in terms of age, gender distribution, primary tumour size, nodal and distant disease. In Korea, where thyroid cancer screening has been undertaken, smaller tumours, higher rates of nodal disease and lower rates of distant disease are described.

CONCLUSION

In our centre, a higher rate of males is treated with larger primary disease and a higher percentage of follicular carcinoma. The reasons for this geographic variation in clinicopathological features in the UK are unclear. As a result, caution should be applied in translating the international move towards a more conservative approach to DTC in the UK in comparison with other areas of the world.

Oncological outcomes in differentiated thyroid cancer in South East Scotland

BACKGROUND

Differentiated thyroid cancer (DTC) is increasing in incidence but little is known about oncological outcomes for patients treated in the UK. Internationally there is a move toward conservative treatment of DTC. However, this is based on evidence from outside the UK. The aim of this study was to analyse oncological outcomes for a contemporary cohort of patients treated in a UK centre.

METHODS

Review of 470 consecutive prospectively recorded cases of DTC from the South East of Scotland endocrine MDT 2009-2018. Data on patient, tumour and treatment details as well as recurrence and survival details were extracted from the electronic patient record.

RESULTS

Of 470 patients female:male ratio was 3.4:1, median age at presentation was 48 years (range 16-86 years). Overall 193 (41%), 134 (29%), 119 (25%) and 22 (5%) patients were p T1, T2, T3, and p T4 respectively. 385 patients (82%) were pN0, 31 patients (7%) were pN1a and 53 patients (11%) were pN1b. 19 patients (4%) were M1. Of 470 patients 350 (74%) had papillary thyroid carcinoma, 120 patients (26%) had follicular carcinoma. Surgical management was lobectomy, isthumusectomy, total thyroidectomy and lobectomy then completion thyroidectomy in 14%,1%, 41% and 43% cases respectively. 64% patients received radioactive Iodine (RAI) therapy. With a median follow-up of 70 months (range 4-124 months), 5 years overall survival and disease specific survival were 96.7% and 98.5% respectively. The 5 year local recurrence free survival (LRFS), regional recurrence free survival (RRFS), locoregional recurrence free survival (LRRFS), distant recurrence free survival (DRFS) and any recurrence free survivals were 100%, 95.8%, 95.8%, 98.3% and 95% respectively.

CONCLUSION

Oncological outcomes for patients treated with DTC were excellent, in keeping with experience from international groups, suggesting that a move towards conservative treatment in the UK seems reasonable.

The Impact of the Extent of Surgery on the Long-Term Outcomes of Patients with Low-Risk Differentiated Non-Medullary Thyroid Cancer: A Systematic Meta-Analysis

Recently, the management of patients with low-risk differentiated non-medullary thyroid cancer (DTC), including papillary and follicular thyroid carcinoma subtypes, has been critically appraised, questioning whether these patients might be overtreated without a clear clinical benefit. The American Thyroid Association (ATA) guideline suggests that thyroid lobectomy (TL) could be a safe alternative for total thyroidectomy (TT) in patients with DTC up to 4 cm limited to the thyroid, without metastases. We conducted a meta-analysis to assess the clinical outcomes in patients with low-risk DTC based on the extent of surgery. The risk ratio (RR) of recurrence rate, overall survival (OS), disease-free survival (DFS) and disease specific survival (DSS) were estimated. In total 16 studies with 175,430 patients met the inclusion criteria. Overall, low recurrence rates were observed for both TL and TT groups (7 vs. 7%, RR 1.10, 95% CI 0.61-1.96, I² = 72%), and no statistically significant differences for OS (TL 94.1 vs. TT 94.4%, RR 0.99, CI 0.99-1.00, I² = 53%), DFS (TL 87 vs. TT 91%, RR 0.96, CI 0.89-1.03, I² = 85%), and DSS (TL 97.2 vs. TT 95.4%, RR 1.01, CI 1.00-1.01, I² = 74%). The high degree of heterogeneity of the studies is a notable limitation. Conservative management and appropriate follow-up instead of bilateral surgery would be justifiable in selected patients. These findings highlight the importance of shared-decision making in the management of patients with small, low-risk DTC.

The impact of completion thyroidectomy

INTRODUCTION

The oncological benefit of completion thyroidectomy (CT) following thyroid lobectomy (TL) is presumed to be similar to that of upfront total thyroidectomy(TT), from a patient's perspective the risk and inconvenience of further surgery adds significantly to the impact of the overall treatment. The aim of this study is to assess the impact of CT in terms of the duration of admission and associated complications.

METHODS

A study of consecutive patients with DTC identified from prospective MDT records of South-East Scotland from 2009 to 2015. Surgical data was extracted from electronic medical record.

RESULTS

Of 361 patients diagnosed with DTC, 161 (45%) had CT. The median postoperative stay was 1 day (range 1-5days). In total 22 patients (14%)suffered complications. Four patients (3%) developed postoperative haematoma. Two (1%) had an identified permanent nerve palsy on the completion side. 13 patients (8%) remained on calcium supplementation for more than 6 months postoperatively and three patients (2%) developed wound complications.

CONCLUSIONS

Our study confirms that CT is regularly performed (45%). Recent changes in international guidelines recognize increasing number of patients as eligible for a conservative approach but recommend CT based on whether upfront TT would have been recommended if the TL pathology were known from the outset. Such an approach fails to consider the additional risk and inconvenience of CT on the overall patient experience. Due to a relatively high rate of complications, only those patients who are most likely to benefit from further surgery to facilitate adjuvant radioactive iodine should be offered additional surgery.

Evaluating the predicted impact of changes to the AJCC/TMN staging system for differentiated thyroid cancer (DTC): A prospective observational study of patients in South East Scotland

OBJECTIVES

To assess the impact of the eighth edition AJCC/TMN staging system on patients with new diagnoses of differentiated thyroid cancers presenting to our regional multidisciplinary team meetings.

DESIGN

We analysed Endocrine Cancer MDT meeting records from 2009 to 2015 to identify all patients in the region presenting with a new diagnosis of differentiated thyroid cancer. We re-staged patients according to the eighth edition AJCC/TNM staging classification and analysed the survival outcomes of patients in each stage under the seventh and eighth systems.

SETTING

Tertiary referral centre in South East Scotland (NHS Lothian).

PARTICIPANTS

Three hundred and sixty-one patients were newly diagnosed with DTC within South East Scotland during the study period and met our inclusion criteria.

MAIN OUTCOME MEASURES

Disease-specific mortality at any time during follow-up.

RESULTS

In total, 119 of 361 (33%) patients were re-staged when the eighth edition AJCC/TMN system was applied. The number of patients classified as having advanced stage (III/IV) disease fell from 76 (21%) to 8 (2%). The most common reason for down-staging was re-classification of tumour size, a factor in 96 (80.7%) down-staged patients. The five-year disease-specific survival of the cohort overall was 98%. Overall, 7 (1.9%) thyroid cancer-related deaths occurred during follow-up, three of whom were down-staged.

CONCLUSIONS

On implementation of the eighth edition of the AJCC/TMN staging system, we expect many patients who would previously have been considered to have advanced thyroid cancer will now be classified as early stage. This will accurately reflect their excellent survival outcomes.