Well-Differentiated Thyroid Cancer: The Philippine General Hospital Experience

Clinical, Histopathological, and Radiological Profile of Patients Presenting With Thyroid Malignancies Among the Kerala Population

BACKGROUND AND OBJECTIVE

Thyroid cancer, though relatively uncommon among all cancer types, stands as the primary form of endocrine tumor. Over the last 20 years, there has been a significant uptick in its occurrence. Papillary thyroid carcinoma (PTC), which is well-differentiated, emerges as the dominant subtype, in regions where iodine levels are deemed adequate. The study aimed to study the clinicopathological profile of patients diagnosed with thyroid malignancies at the Muslim Educational Society (MES) Medical College Perinthalmanna.

MATERIALS AND METHODS

This is a retrospective study undertaken at the MES Medical College by the Department of General Surgery and Endocrine Surgery. The study focuses on patients who have been diagnosed with thyroid cancer through a biopsy. Case sheets of all those patients diagnosed with thyroid malignancy were referred from the Medical Records Library to collect the relevant medical and sociodemographic data. This data was entered in the proforma, which was transferred to the Excel sheet and processed in IBM SPSS Statistics for Windows, Version 20 (Released 2011; IBM Corp., Armonk, New York, United States).

RESULTS

The study included predominantly middle-aged individuals (40-60 years), with 22 (55%) falling within this age range, followed by 14 (35%) aged between 20 and 40 years, and only four (10%) above 60 years. Female patients constituted 82.5% of the study group. Most cases presented with swelling lasting less than six months 23 (57.5%), while only four (10%) had swelling lasting more than five years. Compression symptoms were rare, with only three (7.5%) experiencing dysphagia or dyspnea. Pain was reported in two (5%) of the cases. Hypothyroidism, toxic manifestations, or hoarseness were observed in one (2.5%) of the patients. Regarding swelling characteristics, most were greater than 4 cm in size (29, 72%) and firm in consistency (25, 62.5%). Nodular surfaces were present in 19 (47.5%) of the cases, while 38 (95%) of the swellings were mobile. Palpable lymph nodes were noted in 13 (32.5%) of cases. Radiologically, hypoechoic lesions were observed in 26 (65%) of cases, with microcalcification in 29 (72.5%) and peripheral vascularity in 31 (77.5%). Papillary carcinoma was the most common histological type (34, 85%), with medullary and follicular carcinomas accounting for five (12.5%) and one (2.5%), respectively. An association was found between the duration of swelling and histological type (p = 0.05) and between the mobility of swelling and histological type (p < 0.05). However, no significant associations were observed between imaging findings and histological type (p > 0.05). The gender distribution did not show a statistically significant association with histological type.

CONCLUSION

The findings of the study revealed a statistically insignificant association between age, gender, clinical features, and the histological type of thyroid malignancy. Additionally, there was no statistically significant association between the histological type of thyroid malignancy and the size or type of surface or consistency of thyroid swelling or ultrasonographic findings of the swelling like echogenicity, microcalcification, increased peripheral vascularity, or loss of peripheral halo.

Behaviour and epidemiology of differentiated thyroid cancer among filipinos in and outside the Philippines: Comparison between Qatar, Canada and Philippines

Background

No study assessed the behaviour/epidemiology of differentiated thyroid cancer (DTC) among Filipinos in the Middle East/north Africa; or compared such behaviour with Filipino DTC patients in and outside the Philippines.

Materials and methods

Retrospective review of all adult Filipinos with DTC diagnosed between 2015 and 2020 at our institution [papillary TC (PTC, n = 110); follicular TC (FTC, n = 4)]. Chi-square or t-test compared the frequency, demography, history, ultrasound, laboratory and histopathology of PTC vs FTC; and compared the epidemiology of DTC among Filipinos in Qatar vs Canada (1 study) vs the Philippines (3 studies).

Results

DTC frequency was ≈43.84 cases/100,000 Filipinos in Qatar. Males had more aggressive disease in terms of lymphovascular invasion, number of nodules, stage IV disease and metastases. PTC and FTC were similar, but more PTC patients presented with solid tumors and higher number of involved lymph nodes. DTC behaviour among Filipinos in Qatar vs Canada was fairly homogenous. Conversely, DTC among Filipinos in Qatar vs Philippines exhibited many dissimilarities: Qatar had significantly younger patients, less hyperthyroid/thyrotoxicity symptoms and neck swelling at presentation, fewer solid nodules, micro-calcifications, and multi-nodular disease; smaller tumors; more stage I and less stage IV disease; and no distant metastasis (P 0.01 to < 0.0001).

Conclusions

DTC epidemiology among Filipinos in Qatar and Canada was fairly homogenous. Conversely, DTC in Qatar vs the Philippines was dissimilar. DTC among Filipinos in Qatar has presentations that could be misinterpreted as non-suspicious. This warrants additional practices for earlier detection among Filipinos.

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Epidemiology of differentiated thyroid cancer among Filipinos living Qatar vs Canada has considerable similarities.

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Epidemiology of differentiated thyroid cancer among Filipinos living Qatar vs the Philippines appears to be heterogenous.

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Differentiated thyroid cancer among Filipinos living in Qatar has presentations that could erroneously be misinterpreted as non-malignant by unsuspecting health worker, and seemingly lower tumor load compared to those living in the Philippines.

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Thyroid lesions among Filipinos in Qatar should be taken seriously, warranting additional practices for earlier detection among Filipinos.

Predictors of Response to Therapy Among Post Thyroidectomy Adult Filipino Patients with Papillary Thyroid Carcinoma Based on the 2015 American Thyroid Association Guidelines

Objective

To identify factors independently associated with incomplete response to therapy based on the 2015 ATA guidelines in surgically treated Filipino patients with papillary thyroid carcinoma (PTC).

Methodology

This is a retrospective cohort study of adults aged 21-74 years with papillary thyroid carcinoma (PTC) treated with surgery with or without radioactive iodine therapy (RAI) in Makati Medical Center from 2013 to 2017. We collected the following factors through a review of charts: age at diagnosis, gender, family history of thyroid cancer, date of surgery, tumor size, capsular/lymphovascular invasion, lymph node/distant metastases, stage, risk of recurrence, dose of post-surgical RAI therapy, initial post-treatment serum Thyroglobulin (Tg) and anti-Tg antibody levels (Negative Tg level: suppressed non-stimulated Tg <0.2 ng/mL or TSH-stimulated Tg <1 ng/mL; Positive Tg level: suppressed Tg ≥1 ng/mL or a TSH-stimulated Tg ≥10 ng/mL or rising anti-Tg antibody levels), thyroid stimulating hormone suppression, post-operative imaging studies and levothyroxine dose. Response to therapy was checked 6-24 months post-therapy.

Results

We analyzed a total of 115 patients with PTC who underwent thyroidectomy. Patients who had family history of thyroid cancer were less likely to have an incomplete or indeterminate response (p=0.045). None of the patients with excellent response had lymphovascular invasion. Having a positive Tg (p=0.001) and positive anti-Tg post-operatively (p<0.001) were strongly associated with incomplete or indeterminate response.

Conclusion

Patients who were positive for thyroglobulin and anti-thyroglobulin post-operatively were strongly associated with incomplete or indeterminate response to therapy in PTC.

Clinical predictors of I-131 therapy failure in differentiated thyroid cancer by machine learning: A single-center experience

Well-differentiated thyroid carcinoma is predominantly a slow-growing malignancy, amendable to treatment, and has an excellent prognosis following thyroidectomy and radioiodine (RAI) therapy. However, patients who fail the initial RAI treatment attempt may require repeated RAI or other treatments and with this, comes an associated impact on patient quality of life. Therefore, the anticipation of patients in whom there is a higher risk of RAI failure may help in patient risk stratification and subsequent management. We conducted a retrospective review to determine the factors associated with initial RAI therapy failure in well-differentiated thyroid cancer patients. Using scikit-learn from Python, we implemented a machine-learning algorithm to determine the clinical patient factors associated with a higher likelihood of treatment resistance. We found that clinical factors such as tumor focality (P = 0.026) and lymph node invasion at surgical resection (P = 0.0135) were significantly associated with initial treatment failure following RAI. Elevated serum thyroglobulin (Tg) and Tg antibody levels following surgery but before RAI were also associated with treatment resistance (P < 0.0001 and P = 0.011 respectively). Less expected factors such as decreased time from surgery to RAI were also associated with treatment failure, however not to a statistically significant degree (P > 0.064). Clinical outcomes following RAI can be stratified by identifying factors that are associated with initial treatment failure. These findings can help restratify patients for RAI treatment and change patient management in certain cases. Such stratification will ultimately help to optimize successful treatment outcomes and improve patient quality of life.

Differential Expression of Non-Coding RNA Signatures in Thyroid Cancer between Two Ethnic Groups

Filipino Americans show higher thyroid cancer recurrence rates compared to European Americans. Although they are likely to die of this malignancy, the molecular mechanism has not yet been determined. Recent studies demonstrated that small non-coding RNAs could be utilized to assess thyroid cancer prognosis in tumor models. The goal of this study is to determine whether microRNA (miRNA) signatures are differentially expressed in thyroid cancer in two different ethnic groups. We also determined whether these miRNA signatures are related to cancer staging. This is a retrospective study of archival samples from patients with thyroid cancer (both sexes) in the pathology division from the last ten years at Loma Linda University School of Medicine, California. Deidentified patient demographics were extracted from the patient chart. Discarded formalin-fixed paraffin-embedded tissues were collected post-surgeries. We determined the differential expressions of microRNA in archival samples from Filipino Americans compared to European Americans using the state-of-the-art technique, HiSeq4000. By ingenuity pathway analysis, we determined miRNA targets and the pathways that those targets are involved in. We validated their expressions by real-time quantitative PCR and correlated them with the clinicopathological status in a larger cohort of miRNA samples from both ethnicities. We identified the differentially upregulated/downregulated miRNA clusters in Filipino Americans compared to European Americans. Some of these miRNA clusters are known to target genes that are linked to cancer invasion and metastasis. In univariate analysis, ethnicity and tumor staging were significant factors predicting miR-4633-5p upregulation. When including these factors in a multivariate logistic regression model, ethnicity and tumor staging remained significant independent predictors of miRNA upregulation, whereas the interaction of ethnicity and tumor staging was not significant. In contrast, ethnicity remained an independent predictor of significantly downregulated miR-491-5p and let-7 family. We provide evidence that Filipino Americans showed differentially expressed tumor-tissue-derived microRNA clusters. The functional implications of these miRNAs are under investigation.

Decline in radioiodine use but not total thyroidectomy in thyroid cancer patients treated in the United Arab Emirates - A retrospective study

Objectives

To assess the trend of clinicopathological features and treatment modalities in patients with thyroid cancer (TC) in the largest oncology center in the United Arab Emirates (UAE).

Methods

A retrospective analysis of patients with TC presenting to a tertiary care hospital in Al Ain, UAE between September 2008 and December 2018 identified using ICD 9 & 10 codes was performed. Data on demographics, histopathology, surgical extent, and use of Radioiodine (RAI) were extracted. Exact logistic and ordinal logistic regressions were performed to analyze the annual trend in features and management of TC, and logistic regression analysis was performed to identify predictors of total thyroidectomy and RAI use.

Results

A total of 762 patients were included in the analysis (mean age: 39.6 ± 12.6 years, 45 (60%) women). The majority (92.2%) were diagnosed with papillary thyroid cancer (PTC) and 83.9% had tumor size of <4 cm. All patients underwent surgery (93.8% total thyroidectomy, 6.2% lobectomy) and 77.4% received RAI therapy overall with a significant (p < 0.001) decline from 100% in 2008 to 60% in 2018. In multivariate analysis, nationality, and lymph node (LN) involvement were significant predictors of total thyroidectomy, while nationality, LNs, year of diagnosis, and tumor size significantly predicted RAI use.

Conclusion

Most patients in our cohort were diagnosed with localized PTC with no significant change in the extent of surgical approach but a substantial decline in RAI therapy administration over time. Nationality and LN involvement were significant predictors of surgical extent and RAI use.

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This is the largest study evaluating clinicopathological features and treatment modalities in TC patients in the UAE.

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Most patients were diagnosed with localized PTC.

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A substantial decline in RAI therapy administration but not the extent of thyroidectomy was observed during the study period.

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Nationality and LN involvement were significant predictors of surgical extent and RAI use.

Discrimination of malignant from benign thyroid lesions through neural networks using FTIR signals obtained from tissues

The current gold standard in cancer diagnosis-the microscopic examination of hematoxylin and eosin (H&E)-stained biopsies-is prone to bias since it greatly relies on visual examination. Hence, there is a need to develop a more sensitive and specific method for diagnosing cancer. Here, Fourier transform infrared (FTIR) spectroscopy of thyroid tumors (n = 164; 76 malignant, 88 benign) was performed and five (5) neural network (NN) models were designed to discriminate the obtained spectral data. PCA-LDA was used as classical benchmark for comparison. Each NN model was evaluated using a stratified 10-fold cross-validation method to avoid overfitting, and the performance metrics-accuracy, area under the curve (AUC), positive predictive value (PPV), negative predictive value (NPV), specificity rate (SR), and recall rate (RR)-were averaged for comparison. All NN models were able to perform excellently as classifiers, and all were able to surpass the LDA model in terms of accuracy. Among the NN models, the RNN model performed best, having an AUC of 95.29% ± 6.08%, an accuracy of 98.06% ± 2.87%, a PPV of 98.57% ± 4.52%, a NPV of 93.18% ± 7.93%, a SR value of 98.89% ± 3.51%, and a RR value of 91.25% ± 10.29%. The RNN model outperformed the LDA model for all metrics except for the AUC, NPV, and RR. In conclusion, NN-based tools were able to predict thyroid cancer based on infrared spectroscopy of tissues with a high level of diagnostic performance in comparison to the gold standard.

Clinical management of thyroid aspirates diagnosed as atypia of undetermined significance in the Philippines

Although the cytologic criteria of atypia of undetermined significance (AUS) are defined in The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC), there is heterogeneity in its prevalence, utilization, interpretation, and management. To determine the current practices of physicians of various specialties in the management of thyroid lesions reported as AUS in fine-needle aspirates in the Philippines, a survey consisting of eighteen questions was sent to physicians of varied specialties. Survey questions included geographical location of practice, type of practice (whether in a private or government setting or with academic affiliation), annual patient load, primary operator of fine-needle aspiration (FNA), number of procedures performed, method used, whether by palpation or with ultrasound-guidance, pre-procedure requirements, request for rapid on-site evaluation (ROSE), awareness and utilization of thyroid image reporting and data system (TI-RADS), knowledge of cytologic preparation of aspirates, utilization of TBSRTC nomenclature in the workplace, number of AUS that turned out benign, number of AUS that turned out malignant, management of AUS cases in the setting of patient and physician, utilization of frozen section, implication of surgery over repeat FNA. There were seventy four respondents composed of 20 (27%) otorhinolaryngologists, 15 (20%) pathologists, 14 (19%) endocrinologists, 13 (18%) radiologists, and 12 (16%) general surgeons, practicing in different institutions, with majority (58%) of the respondents based in the National Capital Region. AUS report was encountered by 58 respondents (78%) in up to 10% of their cases, eight respondents (11%) had AUS report in up to 20% of their cases and only one respondent (1%) had AUS report in more than 30% of the cases. Seven (10%), who were mainly radiologists, did not answer the question. Thirty nine physicians (53%) conservatized management with medical follow up and repeat FNA within the time frame prescribed in the Bethesda system, 11 (15%) referred patients with AUS for surgery, 16 (22%) had varied comments. Eight (11%) respondents, who were mainly radiologists, did not answer the question. The data shows that the approach to management of AUS is heterogenous amongst physician-specialists, although, majority of clinicians adhere to the practice guidelines of the American Thyroid Association. Deviation to the guidelines occur since approach to management of patients is individualized.

The Role of postoperative external beam radiotherapy for differentiated thyroid carcinoma: A Systematic review and meta-analysis

The indications for external beam radiotherapy (RT) in differentiated thyroid carcinomas (DTC) are still undefined. The objective of this study was to synthesize current evidence defining the role of postoperative RT in patients with DTC. A systematic review and meta-analysis were done. Included studies compared oncologic outcomes and toxicity of RT vs no RT in patients with DTC. Nine studies were included, two prospective and seven retrospective cohorts. RT improved 5-year locoregional recurrence-free survival but not overall survival and distant metastasis failure-free survival. The locoregional control benefit was seen in patients at increased risk for recurrence, including those with advanced age, locoregionally advanced disease, gross or microscopic residual tumor, and structural invasion. Serious RT-related acute and late toxicities were rare. Available evidence suggests that postoperative RT can improve locoregional control in high-risk DTC with acceptable toxicity. Further prospective studies are warranted.

Cystic Papillary Thyroid Carcinoma: A Case Report

Cystic nodule is an unusual presentation of Papillary Thyroid Carcinoma (PTC), seen in less than 10% of cases. Even by ultrasound, finding a thyroid cyst carries a less than 5% chance of malignancy. We present a case of a 45-year-old male, who came in for incidental finding of a palpable thyroid mass with no significant predisposing history. Thyroidectomy was done and immunohistochemical staining confirmed it to be papillary thyroid cancer. He underwent high dose radiation therapy with post therapy whole body scan showing no evidence of radioavid foci aside from the thyroid bed. The malignant potential of cystic nodule(s) should never be overlooked in certain select patients even if it carries a low chance of malignancy. The diagnosis of PTC relies primarily on the typical nuclear features, however in cases of histologic uncertainty, immunohistochemical stains such as HBME-1 may be used to help classify unusual presentations of PTC. Treatment and monitoring of Cystic Papillary Thyroid Carcinoma follows the conventional guideline on solid PTC.

Follicular thyroid cancer and Hürthle cell carcinoma: challenges in diagnosis, treatment, and clinical management

Follicular thyroid cancer is the second most common differentiated thyroid cancer histological type and has been overshadowed by its more common counterpart-papillary thyroid cancer-despite its unique biological behaviour and less favourable outcomes. In this Review, we comprehensively review the literature on follicular thyroid cancer to provide an evidence-based guide to the management of these tumours, to highlight the lack of evidence behind guideline recommendations, and to identify changes and challenges over the past decades in diagnosis, prognosis, and treatment. We highlight that correct identification of cancer in indeterminate cytological samples is challenging and ultrasonographic features can be misleading. Despite certain unique aspects of follicular thyroid cancer presentation and prognosis, no specific recommendations exist for follicular thyroid cancer and Hürthle cell carcinoma in evidence-based guidelines. Efforts should be made to stimulate additional research in this field.

Validity and Reliability of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 - Tagalog among Adult Filipinos with Differentiated Thyroid Cancer

Objective

This study aims to determine the convergent and discriminant validity and internal consistent reliability of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) Tagalog among adult Filipinos with differentiated thyroid cancer (DTC).

Methodology

104 adult Filipinos with DTC at various disease stages self-administered the EORTC QLQ-C30 version 3 Tagalog and Short Form-36 (SF-36) version 2 Tagalog. Concurrent validity between conceptually-related scales from both tools was determined. Convergent and discriminant validity of multi-item scales of the EORTC QLQ-C30 Tagalog were assessed by Spearman’s correlation. Cronbach's α was computed.

Results

The EORTC QLQ-C30 Tagalog showed moderate correlation with similar scales in the SF-36 Tagalog particulary for physical, role and social functioning, pain, and global health (r=0.42-0.48, p<0.001). It showed satisfactory item-domain convergent and discriminant validity for all scales except pain, fatigue, physical and cognitive functioning. Internal consistent reliability was good with cronbachs α ranging from 0.77 to 0.88 for global health, emotional and role functioning and symptom scale of nausea/vomiting.

Conclusion

The EORTC QLQ-C30 Tagalog had acceptable convergent and discriminant validity and internal consistent reliability for the scales of global health, role, social and emotional functioning and nausea/vomiting when applied among adult Filipinos with DTC.

Thyroid Fine-Needle Aspiration Practice in the Philippines

Fine-needle aspiration (FNA) is a well accepted initial approach in the management of thyroid lesions. It has come a long way since its introduction for nearly a century ago. In the Philippines, FNA of the thyroid was first introduced 30 years ago and has been utilized until now as a mainstay in the diagnosis of thyroid malignancy. The procedure is performed by pathologists, endocrinologists, surgeons, and radiologists. Most pathologists report the cytodiagnosis using a combination of the aspiration biopsy cytology method that closely resembles the histopathologic diagnosis of thyroid disorders and the six-tier nomenclature of The Bethesda System for Reporting Thyroid Cytopathology. Local endocrinologists and surgeons follow the guidelines of the 2015 American Thyroid Association in the management of thyroid disorders. There is still a paucity of local research studies but available data deal with cytohistologic correlations, sensitivity, specificity, and accuracy rates as well as usefulness of ultrasound-guided FNA. Cytohistologic correlations have a wide range of sensitivity from 30.7% to 73% and specificity from 83% to 100%. The low sensitivity can be attributed to poor tissue sampling since a majority of the thyroid FNA is done by palpation only. The reliability can be improved if FNA is guided by ultrasound as attested in both international and local studies. Overall, FNA of the thyroid has enabled the diagnosis of thyroid disorders with an accuracy of 72.8% to 87.2% and it correlates well with histopathology.

Thyroid cancer mortality is higher in Filipinos in the United States: An analysis using national mortality records from 2003 through 2012

BACKGROUND

Well-differentiated thyroid carcinoma has a favorable prognosis, but patients with multiple recurrences have drastically lower survival. Filipinos in the United States are known to have high rates of thyroid cancer incidence and disease recurrence. To the authors' knowledge, it is unknown whether Filipinos also have higher thyroid cancer mortality rates.

METHODS

The authors studied thyroid cancer mortality in Filipino, non-Filipino Asian (NFA), and non-Hispanic white (NHW) adults using US death records (2003-2012) and US Census data. Age-adjusted mortality rates and proportional mortality ratios (PMRs) were calculated. Sex, nativity status, age at death, and educational attainment also were examined.

RESULTS

The authors examined 19,940,952 deaths. The age-adjusted mortality rates due to thyroid cancer were highest in Filipinos (1.72 deaths per 100,000 population; 95% confidence interval [95% CI], 1.51-1.95) compared with NFAs (1.03 per 100,000 population; 95% CI, 0.95-1.12) and NHWs (1.17 per 100,000 population; 95% CI, 1.16-1.18). Compared with NHWs, higher proportionate mortality was observed in Filipino women (3-5 times higher) across all age groups, and among Filipino men, the PMR was 2 to 3 times higher in the subgroup aged >55 years. Filipinos who completed a higher educational level had a notably higher PMR (5.0) compared with their counterparts who had not (3.5).

CONCLUSIONS

Negative prognostic factors for thyroid cancer traditionally include age >45 years and male sex. The results of the current study demonstrate that Filipinos die of thyroid cancer at higher rates than NFA and NHW individuals of similar ages. Highly educated Filipinos and Filipino women may be especially at risk of poor thyroid cancer outcomes. Filipino ethnicity should be factored into clinical decision making in the management of patients with thyroid cancer. Cancer 2017;123:4860-7. © 2017 American Cancer Society.

Poorly Differentiated Thyroid Carcinoma: 10-Year Experience in a Southeast Asian Population

BACKGROUND

No previous studies have been published on poorly differentiated thyroid carcinoma (PDTC) in Southeast Asia.

METHODS

We included all adult PDTC patients diagnosed using the Turin criteria at the Philippine General Hospital from 2006 to 2015. The data collected included demographics, clinical presentation, histopathology, treatment, and outcomes. Tests of association were employed to compare these data with foreign studies on PDTC, as well as with local studies on well differentiated thyroid carcinoma (WDTC) and anaplastic thyroid carcinoma (ATC).

RESULTS

Eighteen PDTC cases were identified. The median age was 62 years old, with the majority being females. All patients had goiter on presentation, and most were stage IV at the time of diagnosis. In terms of PDTC subtype, insular and trabecular patterns were equally common. Extrathyroidal extension was documented in eight patients, while five patients each had nodal and distant metastasis. All but one patient underwent surgery; however, less than half received adjuvant radioiodine therapy. The 5-year survival rate was 83%. Three patients (16.7%) died at a median of 12 months after diagnosis. Nine (50%) are still alive with persistent and/or recurrent disease at a median of 39 months after diagnosis.

CONCLUSION

The behavior of PDTC in this Southeast Asian population was found to be similar to patterns observed in other regions, and exhibited intermediate features between WDTC and ATC. Appropriate surgery provided excellent 5-year survival rates, but the role of adjuvant therapy remains unclear. Larger studies are needed to identify prognostic factors in this population.