Hashimoto's thyroiditis on outcomes in papillary thyroid cancer revisited: experience from South East Asia.

INTRODUCTION: The association between Hashimoto Thyroiditis (HT) and papillary thyroid cancer (PTC) remains uncertain. HT, the most common inflammatory condition of the thyroid, is postulated to increase the risk of PTC and yet confer cancer-retarding effects. In this study, we aim to evaluate the prevalence of HT in patients surgically treated for PTC and evaluate the long-term prognostic implications. METHODS: This is a retrospective study of 521 patients with PTC who underwent hemi- or total thyroidectomy between January 2000 and December 2018 at a tertiary referral centre. Patients were categorised into two group: group A (n=402) consists of patients with PTC without HT, whereas group B (n=119) consists of patients with PTC and HT. Demographic and clinicopathological details, recurrence rates and overall survival were collected. Univariate and multivariate analyses were performed to evaluate for clinical factors associated with HT. RESULTS: A total of 521 patients with a mean age of 46.7 years were evaluated. HT was detected in 22.8% of patients with PTC. On multivariate analysis, presence of HT was associated with a lower incidence of extrathyroidal extension (hazard ratio: 0.59, 95%confidence interval 0.37-0.95). Also, patients with HT tend to have fewer cycles of radioactive iodine and correspondingly have excellent response to treatment. However, no differences in recurrence rates and overall survival were detected. CONCLUSIONS: One-fifth of patients with PTC have coexisting HT. These patients tend to have less-aggressive tumour features such as extrathyroidal extension. However, the effect of HT on recurrence and overall survival appears to be inconsequential clinically.

Comparison of prognostic scoring systems in follicular thyroid cancer.

INTRODUCTION Many studies have addressed the accuracy of prognostic scoring systems in the treatment of differentiated thyroid cancers as a whole but few have addressed this issue in patients with follicular thyroid cancer (FTC) alone. The aim of this study was to establish the accuracy of the various scoring systems in determining the overall and disease free survival of FTC patients in Singapore. METHODS Retrospective review was undertaken of 82 patients with FTC treated at a single tertiary institution between January 2000 and December 2014. Demographic, clinical, pathological and treatment outcomes were analysed. Prognostic scoring systems evaluated for the cohort included TNM (Tumour, Nodes, Metastases), AGES (Age, Grade, Extent, Size), MACIS (Metastases, Age, Completeness of resection, Invasion, Size), AMES (Age, Metastases, Extent, Sex) and EORTC (European Organisation for Research and Treatment of Cancer). Statistical analysis was performed by plotting Kaplan-Meier survival curves and using the Cox proportional hazards model. RESULTS There were 29 male and 53 female patients with a mean age of 48 years. The mean follow-up duration was 88 months and there were 7 deaths (9%). The ten-year overall survival rate was 90%. Factors predictive of survival on univariate analysis were age, size of tumour, invasiveness, completeness of resection, metastasis, external beam radiotherapy, and risk scores using the AGES and MACIS scoring systems (p<0.05). On multivariate analysis, AGES and MACIS provided the best prognostic information. CONCLUSIONS MACIS is the best prognostic scoring system currently available for FTC and it is superior to other scoring systems in term of guiding management. The scoring systems require further development to accommodate variations in clinical practice globally and to improve the prognostic accuracy.

Patterns of metastasis in follicular thyroid carcinoma and the difference between early and delayed presentation.

Introduction Follicular thyroid cancer (FTC) has a good prognosis if treated early. The aim of this study was to look at the difference in outcomes in those who presented with metastasis early or late in their disease. Methods A retrospective cohort study was conducted of patients diagnosed with FTC (n=91) treated between 2000 and 2013. Demographic, laboratory, pathological and survival data were collected and analysed. Results Metastatic FTC was diagnosed in 20 cases (22%). The median age at diagnosis was 65 years (range: 17-86 years) and 65% of the patients were female. Twelve patients (60%) were diagnosed with metastatic disease at presentation, with the bones being the most common site (75%). In the remaining eight cases (40%), metastasis developed at a median of 4.5 years (range: 2-8 years) after initial thyroid surgery, lungs being the most common site (50%). Eighteen patients (90%) underwent surgical intervention for the primary disease. Sixteen patients (80%) received adjuvant radioactive iodine and eight (40%) received external beam radiotherapy. Widely invasive follicular cancer was the predominant histological diagnosis (90%). No prognostic association was observed with any of the parameters studied. The overall disease specific mortality rate was 40%. There was no significant difference in mortality between those who presented with metastatic disease and those who developed metastasis during the follow-up period (33% vs 50%, p=0.61). Conclusions The clinical outcome and prognosis for cases with metastatic disease is generally poor. Despite this, almost half of the patients in our study were still alive at a median follow-up of 5.5 years, regardless of whether they were diagnosed with metastatic disease on initial presentation or whether they developed metastasis after initial thyroid surgery.