Disease-related death in patients who were considered free of macroscopic disease after initial treatment of well-differentiated thyroid carcinoma

Hashimoto's Thyroiditis: A Protective Factor against Recurrence in BRAF-Wild Type Differentiated Thyroid Carcinoma

A recent work analyzing the concomitant factors BRAF mutation (risk factor) and Hashimoto's thyroiditis (HT) (protective factor) found that the presence of HT reduced lymph node metastasis in BRAF-mutated papillary thyroid carcinoma. Whether this notion is upheld with respect to disease recurrence and differentiated thyroid carcinoma (DTC), however, is unknown. We aimed to investigate the effect of underlying HT in DTC patients and its influence on recurrence with a specific emphasis in BRAF-mutated tumors. A total of 469 patients were included. Patients were stratified according to BRAF and HT status. Multivariate regression analysis was conducted to determine protective and risk factors of disease recurrence in patients with DTC. HT was associated with less-aggressive carcinomas including more frequent microcarcinomas (HT: 45.0% vs. no-HT: 34.0%, p = 0.02), less lymph node involvement (HT: 16.4% vs. no-HT: 26.1%, p = 0.02), and less disease recurrence (HT: 2.9% vs. no-HT: 11.9%, p = 0.002). BRAF mutation was also significantly associated with higher rates of lymph node involvement (BRAF-mutant: 41.9% vs. BRAF-wild type: 14.6%, p < 0.001) and almost two times the rate of recurrence (BRAF-mutant: 14.9% vs. BRAF-wild type: 6.5%, p = 0.004). Underlying HT was the only protective factor determined, reducing the odds of developing recurrence by 70% (HR: 0.30, 95%CI: 0.11-0.88). In the BRAF-wild type cohort, regression analysis continued to determine HT as a protective factor (p = 0.03). However, in the BRAF-mutant cohort, HT was no longer an independent protective factor (p = 0.20) against recurrence. Sub-group regression analysis, including PTC patients, similarly found HT as a protective factor only in BRAF-wild type patients (p = 0.039) and not BRAF-mutant (p = 0.627). The presence of underlying HT is associated with less aggressive tumors and is an independent protective factor against DTC recurrence, reducing the risk by 70%. HT remains a protective factor in BRAF-wild type carcinoma, but not in patients with BRAF-mutant carcinoma. HT may potentially be considered as a parameter which enhances American Thyroid Association patient risk stratification.

Central node dissection in papillary thyroid carcinoma in the era of near-infrared fluorescence

The most common site of lymph node metastases in papillary thyroid carcinoma is the central compartment of the neck (level VI). In many patients, nodal metastases in this area are not clinically apparent, neither on preoperative imaging nor during surgery. Prophylactic surgical clearance of the level VI in the absence of clinically suspicious lymph nodes (cN0) is still under debate. It has been suggested to reduce local recurrence and improve disease-specific survival. Moreover, it helps to accurately diagnose the lymph node involvement and provides important staging information useful for tailoring of the radioactive iodine regimen and estimating the risk of recurrence. Yet, many studies have shown no benefit to the long-term outcome. Arguments against the prophylactic central lymph node dissection (CLND) cite minimal oncologic benefit and concomitant higher operative morbidity, with hypoparathyroidism being the most common complication. Recently, near-infrared fluorescence imaging has emerged as a novel tool to identify and preserve parathyroid glands during thyroid surgery. We provide an overview of the current scientific landscape of fluorescence imaging in thyroid surgery, of the controversies around the prophylactic CLND, and of fluorescence imaging applications in CLND. To date, only three studies evaluated fluorescence imaging in patients undergoing thyroidectomy and prophylactic or therapeutic CLND for thyroid cancer. The results suggest that fluorescence imaging has the potential to minimise the risk of hypoparathyroidism associated with CLND, while allowing to exploit all its potential benefits. With further development, fluorescence imaging techniques might shift the paradigm to recommend more frequently prophylactic CLND.

Well-Differentiated Thyroid Cancer: Who Should Get Postoperative Radiation?

BACKGROUND

The mainstay of treatment of well-differentiated thyroid cancer (WDTC) is surgery followed by adjuvant radioactive iodine therapy. Postoperative radiation therapy (PORT) is rarely used.

OBJECTIVE

The aim of our study was to report our experience of patients with WDTC who were selected to receive PORT.

MATERIALS AND METHODS

After Institutional Review Board approval, patients who received PORT were identified from a departmental database of 6259 patients with WDTC treated with primary surgery from 1986 to 2015. We carried out propensity matching to compare outcomes with a cohort of patients who did not receive PORT. The main outcome of interest was central neck recurrence-free probability (CNRFP), while secondary outcomes were lateral neck recurrence-free probability (LNRFP), disease-specific survival (DSS), and overall survival (OS).

RESULTS

From 6259 patients, 32 (0.5%) patients with a median age of 65.2 years received PORT. Tall-cell variant papillary thyroid carcinoma was the most common pathology (45%). Patients who received PORT had no difference in CNRFP compared with patients treated without PORT (10-year CNRFP 88% vs. 73%; p = 0.18). Furthermore, patients who received PORT had superior LNRFP (10-year LNRFP 100% vs. 62%; p = 0.001) compared with the no-PORT cohort. Despite this, patients who received PORT had similar DSS (71% PORT vs. 75% no-PORT) and OS (65% PORT vs. 58% no-PORT group) as the no-PORT cohort.

CONCLUSIONS

Our data show that select patients who received PORT had improved locoregional recurrence-free probability; however, this did not translate into improved DSS and OS. At our institution, we recommend the use of PORT only in highly selected patients with locally advanced primary tumors who are deemed to have a high risk of central neck recurrence for which salvage surgery would result in unacceptable risk to the airway.

Risk stratification in differentiated thyroid cancer with RAI-avid lung metastases

OBJECTIVE

Radioactive iodine (RAI) therapy is effective for differentiated thyroid cancer (DTC) patients with lung metastasis. However, some patients have a poor prognosis despite the RAI accumulation. The utility of inflammatory biomarkers, including neutrophil-to-lymphocyte ratio (NLR), has been reported as a prognostic factor for many carcinomas. This study aimed to investigate the risk factors related to DTC patient survival with RAI-avid lung metastasis and to attempt risk stratification.

DESIGN AND METHODS

This retrospective study included 123 patients with RAI-accumulating lung metastatic DTC. The cause-specific survival (CSS) rate from the time of detection of lung metastasis was tested using the Kaplan-Meier log-rank test, and the multivariate analysis was calculated using the Cox proportional hazards model. NLR was retrospectively calculated using the blood sample collected before initial RAI treatment. The NLR cutoff value was 2.6 on the ROC curve.

RESULTS

Age ≥ 55 years at the time of operative treatment, follicular carcinoma, lung metastasis tumor ≥ 10 mm in diameter, age ≥ 55 years at the time of detection of lung metastasis, age ≥ 55 years at the time of RAI treatment, and NLR ≥ 2.6 at the initial RAI treatment were predictive of decreased CSS. Multivariate analysis identified that the independent prognostic factors were lung metastatic tumor ≥ 10 mm in diameter and NLR ≥ 2.6. Patients in the high-risk group with both factors had significantly lower CSS rates than those in the low- and intermediate-risk groups with one or none of these factors.

CONCLUSIONS

The high-risk group patients had significantly poorer survival, and these patients could be considered as future candidates for tyrosine kinase inhibitor therapy.

Central lymph node dissection and permanent hypoparathyroidism after total thyroidectomy for papillary thyroid cancer: population-based study

BACKGROUND

Papillary thyroid cancer is treated with total/near-total thyroidectomy (TT) with or without central lymph node dissection (CLND), depending on risk factors and tumour size. Balancing the risk of disease recurrence and surgical morbidity remains a challenge. A population-based nationwide study was undertaken to evaluate the risk of permanent hypoparathyroidism associated with CLND.

METHOD

Data on patients with stage pT1-3 papillary thyroid cancer, who underwent TT with or without CLND between 1 July 2004 and 30 June 2014 were retrieved from the Scandinavian Quality Register for Thyroid, Parathyroid and Adrenal Surgery. Drug use was ascertained by cross-linking with the Swedish Prescribed Drug Register. Permanent hypoparathyroidism was defined as treatment with active D vitamin or oral calcium drugs for more than 6 months after surgery. Data were analysed separately for all patients and those who underwent TT + CLND. Univariable and multivariable logistic regression analyses were done, yielding odds ratios (ORs) with 95 per cent confidence intervals.

RESULTS

A total of 722 patients were included in the study. Permanent hypoparathyroidism was more common in the TT + CLND group than the TT group: 30 of 265 patients (6·6 per cent) versus six of 457 (2·3 per cent) (P = 0·011). In multivariable logistic regression analysis, CLND was a risk factor for permanent hypoparathyroidism (OR 3·74, 95 per cent c.i. 1·46 to 9·59, based on use of combined therapy 6 months after surgery). In patients who had TT + CLND, node negativity was associated with a risk of permanent hypoparathyroidism (OR 3·08, 1·31 to 7·25).

CONCLUSION

CLND is an independent risk factor for permanent hypoparathyroidism. Node negativity is associated with a higher risk of permanent hypoparathyroidism.

Percutaneous thermal ablation of lung metastases from thyroid carcinomas. A retrospective multicenter study of 107 nodules. On behalf of the TUTHYREF network

PURPOSE

To determine efficacy and safety of thermal ablation (TA) for the local treatment of lung metastases of thyroid cancer.

METHODS

We retrospectively studied 47 patients from 10 centers treated by TA (radiofrequency, microwaves, and cryoablation) over 10 years. The endpoints were overall survival (OS), local efficacy, complications (CTCAE classification), and factors associated with survival. OS curves after first TA were built using the Kaplan-Meier method and compared with the log-rank test.

RESULTS

A total of 107 lung metastases during 75 sessions were treated by radiofrequency (n = 56), microwaves (n = 9), and cryoablation (n = 10). Median follow-up time after TA was 5.2 years (0.2-13.3). OS was 93% at 2 years (95% confidence interval (CI): 86-94) and 79% at 3 years (95% CI: 66-91). On univariate and multivariate analysis with a Cox model, histology was the only significant factor for OS. OS at 3 years was 94% for follicular, oncocytic, or papillary follicular variant carcinomas, compared to 59% for papillary, medullary, insular or anaplastic carcinomas (P = 0.0001). The local control rate was 98.1% at 1 year and 94.8% at 2, 3, 4, and 5 years. Morbidity was low with no major complications (grade 4 and 5 CTCAE) and no complications in 29 of 75 sessions (38.7%).

CONCLUSIONS

TA is a useful, safe and effective option for local treatment of lung metastases from thyroid carcinoma. Prolonged OS was obtained, especially for lung metastases from follicular, oncocytic, or papillary follicular variant carcinomas. Achieving disease control with TA delays the need for systemic treatment.

Therapeutic Outcomes of Recurrent Well-Differentiated Thyroid Carcinomas

Objective

The aim of this study was to evaluate outcomes of the recurrent and non-recurrent groups including disease-specific mortality of patients with well-differentiated thyroid carcinoma after multimodality treatment. In addition, prognostic factors for disease-specific mortality were analyzed.

Summary of Background Data

Among 2,844, there were 166 patients with recurrent disease. Recurrent disease was defined as the presence of papillary or follicular thyroid cancer 6 months after the initial thyroidectomy, including locoregional or distant metastasis, diagnosed using diagnostic or therapeutic 131I scans or other imaging techniques.

Methods

The study was a retrospective analysis of prospectively collected data for a long-term follow-up result of well-differentiated thyroid carcinoma patients.

Results

The mean age of 166 patients was 45.8 ± 1.2 years, 116 (69.9%) were women, 111 (66.9%) had locoregional neck recurrence, and 55 (33.1%) had metastatic recurrence in distant organs. We found that when recurrences were observed, more than half were detected within the first 5 years following the initial therapy. The longest period of time before relapse was 29.8 years. After a mean follow-up period of 12.7 ± 0.5 years, 37 (22.3%) patients experienced disease-specific mortality. Multivariable analysis revealed that older age, male sex, and development of a second primary malignancy were associated with disease-specific mortality. Higher post-operative levels of thyroglobulin predicted a shorter time to relapse.

Conclusions

These data indicate that among the recurrent cases over 50% of recurrent well-differentiated thyroid carcinomas were diagnosed within 5 years after initial thyroidectomy. Additionally, more than 20% of the patients died of thyroid cancer.

Clinical Course from Diagnosis to Death in Patients with Well-Differentiated Thyroid Cancer

Because of the low mortality rate of well-differentiated thyroid cancer (WDTC), investigation of the clinical course leading to death is limited. We analyzed the cause of death and clinical course from diagnosis to death in patients who died of WDTC. A total of 592 WDTC patients died between 1996 and 2018. After exclusion, 79 patients were enrolled and divided into four groups based on their clinical course; that is, inoperable at the time of diagnosis (inoperable), distant metastasis (DM) detected at the time of diagnosis (initial-DM), DM detected during follow-up (late-DM), and loco-regional disease (L-R). Lung (55.6%) in papillary thyroid carcinoma (PTC) and bone (46.7%) in follicular thyroid carcinoma (FTC) were the most common metastasis locations. The most common causes of death were respiratory failure (32.3%) and airway obstruction (30.6%) in PTC, and complications due to immobilization arising from bone metastasis (35.3%) in FTC. Brain metastasis was found in 13.3% of patients and had the worst prognosis. The overall survival (OS) differed significantly (p = 0.001) according to clinical course; the inoperable had the shortest survival, followed by the initial-DM, L-R, and late-DM. However, OS did not differ significantly between PTC and FTC patients with initial-DM (p = 0.83). Other causes of death were far more common than death resulting from WDTC. In patients dying of WDTC, the major cause of death varied by metastatic site. OS differed according to clinical course, but not histologic type. Timing and DM sites differed between PTC and FTC.

Poorly Differentiated Carcinoma of the Thyroid Gland: Current Status and Future Prospects

BACKGROUND

Poorly differentiated thyroid cancer (PDTC) is a rare but clinically highly significant entity because it accounts for most fatalities from non-anaplastic follicular cell-derived thyroid cancer. Due to the relative rarity of the disease and heterogeneous diagnostic criteria, studies on PDTC have been limited. In light of the evolution of ultra-deep next-generation sequencing technologies and through correlation of clinicopathologic and genomic characteristics of PDTC, an improved understanding of the biology of PDTC has been facilitated. Here, the diagnostic criteria, clinicopathologic characteristics, management, and outcomes in PDTC, as well as genomic drivers in PDTC reported in recent next-generation sequencing studies, are reviewed. In addition, future prospects in improving the outcomes in PDTC patients are reviewed.

SUMMARY

PDTC patients tend to present with adverse clinicopathologic characteristics: older age, male predominance, advanced locoregional disease, and distant metastases. Surgery with clearance of all gross disease can achieve satisfactory locoregional control. However, the majority of PDTC patients die of distant disease. Five-year disease-specific survival for PDTC patients has been reported at 66%. On multivariate analysis, reported predictors of poor survival in PDTC patients have been older age (>45 years), T4a pathological stage, extrathyroidal extension, high mitotic rate, tumor necrosis, and distant metastasis at presentation. BRAF^V600E or RAS mutations (27% and 24% of cases, respectively) remain mutually exclusive main drivers in PDTC. TERT promoter mutations represent the most common alteration in PDTC (40%). Mutation in translation initiation factor EIF1AX (11%) and tumor suppressor TP53 (16%) have also been reported in PDTC. High rates of novel mutations (MED12 and RBM10) have been reported in fatal PDTC (15% and 12%, respectively). Chromosome 1q gains represent the most common arm-level alterations in PDTC, and those patients show worse survival rates. Chromosome 22q losses are also found in PDTC and show strong association with RAS mutation.

CONCLUSIONS

These new insights into the clinicopathologic and molecular characteristics of PDTC, together with further advancement in ultra-deep sequencing technologies, will be conducive in narrowing the focus in order to develop novel targeted therapies and improve the outcomes in PDTC patients.

The efficacy of radioactive iodine for the treatment of well-differentiated thyroid cancer with distant metastasis

Objective

Radioactive iodine (¹³¹I) has been used as a treatment for high-risk well-differentiated thyroid cancer after thyroidectomy. The aim of this study was to evaluate the long-term follow-up results after using high accumulated doses of ¹³¹I (>600 mCi) for the treatment of well-differentiated thyroid cancer.

Patients and methods

In this study, we retrospectively evaluated prospectively enrolled patients with well-differentiated thyroid cancer who were treated and followed up in Chang Gung Memorial Hospital in Linkou and Keelung, Taiwan. All the patients underwent thyroidectomy between 1979 and 2016.

Results

For our study, 228 patients with papillary and follicular thyroid carcinoma with distant metastases were enrolled. Of the 228 patients, 71 (31.1%) received ¹³¹I therapy with an accumulated dose of at least 600 mCi. Forty-four died because of disease-specific mortality (DSM) after a mean follow-up of 10.6±6.3 years. Compared with the patients in the DSM group, which included 27 survival cases, patients who were younger, and those with a multifocal tumor, more extensive thyroidectomy, and papillary thyroid carcinoma showed better prognosis. The DSM group included a higher percentage of patients who developed a secondary primary cancer after receiving a diagnosis of thyroid cancer than the survival group (18.2 vs. 3.7%). However, the difference did not reach statistical significance (P=0.075).

Conclusion

¹³¹I provided an effective therapeutic modality for well-differentiated thyroid cancer patients with distant metastasis. After a mean of follow-up 10 years, more than 60% of cases resulted in DSM when high accumulated ¹³¹I doses were administered.

Disease Severity at Presentation in Patients with Disease-Related Mortality from Differentiated Thyroid Cancer: Implications for the 2015 ATA Guidelines

BACKGROUND

The current trend of less aggressive treatment of low-risk differentiated thyroid cancer (DTC) patients was recently challenged by a study reporting >10% disease-related mortality (DRM) in low-risk patients ablated with radioiodine activities below 54 mCi. However, this study and others were limited by incomplete data on disease severity at presentation. Whether patients presenting with low-risk disease are at risk for disease-related mortality is crucial for planning current treatment strategies.

METHODS

Patients with documented DRM from DTC were included from the Rabin thyroid cancer registry and the Davidoff Head and Neck cancer service databases. Disease characteristics at presentation, treatments, disease course, and cause of death were analyzed.

RESULTS

Of 1374 patients whose charts were reviewed, 56 were confirmed to have died of DTC, and 53 had sufficient data for analysis. Median time from diagnosis to death was 9 years (range 1-36). Cause of death was related to distant metastases in 46 patients and aggressive neck disease in 7 patients. The median age at diagnosis was 62 years (range 22-83, 83% older than 45), and were initially categorized as American Thyroid Association high risk in 89% of cases (in 4 cases due to high thyroglobulin levels), intermediate risk in 6% (3 older patients with N1b disease), misclassification as benign in one case, and none was low risk. Most patients had an advanced disease stage (stage IV, 88%; III, 2%; II, 2%; I, 8%). All patients with stage I disease were <45 years, with aggressive features (1 poorly differentiated, 3 gross extrathyroidal extension). One patient with stage II disease was <45 years and had distant metastases. Detection of distant metastases occurred within the first year in 25 patients and during subsequent follow-up in 25 patients. Overall, aside from one patient who was misdiagnosed as having a benign follicular adenoma at presentation, all patients had aggressive disease features at presentation.

CONCLUSION

None of the patients with DRM had low-risk features at presentation, supporting the current paradigm of less aggressive approach in the low-risk group. Studies analyzing mortality from thyroid cancer should stratify patients into the various risk categories based on full baseline data, including postoperative thyroglobulin levels.

Deaths related to differentiated thyroid cancer: a rare but real event

Objective

The present study describes the clinical and tumor characteristics of patients that died from differentiated thyroid cancer and reports on the cause and circumstances of death in these cases.

Subjects and methods

Retrospective analysis of all the differentiated thyroid cancer (DTC) related deaths at a single institution over a 5-year period, with a total of 33 patients.

Results

Most of the patients were female (63.6%), with a mean age at diagnosis of 58.2 years. The most common histologic type was papillary (66.7%) and 30.3% were follicular. The distribution according to the TNM classification was: 15.4% of T1; 7.7% T2; 38.4% T3; 19.2% of T4a and 19.2% of T4b. Forty-four percent of cases were N0; 20% N1a and 36.6% of N1b. Twelve patients were considered non-responsive to radioiodine. Only one of the patients did not have distant metastases. The most common metastatic site was the lung in 69.7%. The majority of deaths were due to pulmonary complications related to lung metastases (17 patients, 51.5%), followed by post-operative complications in 5 cases, neurological disease progression in 3 cases, local invasion and airway obstruction in one patient. Median survival between diagnosis and death was reached in 49 months while between disease progression and death it was at 22 months.

Conclusion

Mortality from DTC is extremely rare but persists, and the main causes of death derive from distant metastasis, especially respiratory failure due to lung metastasis. Once disease progression is established, median survival was only 22 months.

DEATH RELATED TO PULMONARY METASTASIS IN PATIENTS WITH DIFFERENTIATED THYROID CANCER

OBJECTIVE

The purpose of the present study was to investigate the predictive factors for shorter disease-specific survival in patients with pulmonary disease secondary to differentiated thyroid cancer (DTC).

METHODS

This was a retrospective cohort study conducted over a 5-year period that included 54 patients with pulmonary disease secondary to DTC during the follow-up. Among these patients, 13 (24.1%) died from the disease. Dedifferentiation characteristics were identified at pathological examination of the metastatic disease (lymph node or distant metastases) and was defined as the abrupt transformation of a well-differentiated tumor into high-grade morphology lacking the original distinct histologic characteristics.

RESULTS

Tumor dedifferentiation marked by cellular aberrations and radioiodine (RAI) therapy resistance occurred in 5 (9.3%) patients. Four of them died due to pulmonary progression (80.0%), and the median survival of this group was 30 months compared to 279 months in the patients without dedifferentiation. The cumulative disease-specific survival was 20.0% in the patients with dedifferentiation during the follow-up versus 46.1% among the cases without this condition (P = .003, log-rank test). Moreover, dedifferentiation was independently associated with shorter disease-specific survival (hazard ratio [HR] = 31.607; 95% confidence interval [CI]: 4.815-207.478; P<.0001, Cox regression model) as were age over 45 years (HR = 10.904; 95% CI: 1.145-103.853; P = .038) and male sex (HR = 4.210; 95% CI: 1.056-16.783; P = .042).

CONCLUSION

DTC patients with pulmonary disease exhibited shorter disease-specific survival, particularly those who developed tumor dedifferentiation, and these patients require special attention during follow-up.

ABBREVIATIONS

CI = confidence interval DTC = differentiated thyroid cancer FTC = follicular thyroid carcinoma HR = hazard ratio IQR = interquartile range LN = lymph node LR = likelihood ratio PTC = papillary thyroid carcinoma RAI = radioiodine pTNM = pathologic tumor-node-metastasis stage system.

Management of Invasive Differentiated Thyroid Cancer

BACKGROUND

Invasive disease is a poor prognostic factor for patients with differentiated thyroid cancer (DTC). Uncontrolled central neck disease is a common cause of distressing death for patients presenting in this manner. Advances in assessment and management of such cases have led to significant improvements in outcome for this patient group. This article reviews the patterns of invasion and a contemporary approach to investigation and treatment of patients with invasive DTC.

SUMMARY

Aerodigestive tract invasion is reported in around 10% of case series of DTC. Assessment should include not only clinical history and physical examination with endoscopy as indicated, but ultrasound and contrast-enhanced cross-sectional imaging. Further studies including positron emission tomography should be considered, particularly in recurrent cases that are radioactive iodine (RAI) resistant. Both the patient and the extent of disease should be carefully assessed prior to embarking on surgery. The aim of surgery is to resect all gross disease. When minimal visceral invasion is encountered early, "shave" procedures are recommended. In the setting of transmural invasion of the airway or esophagus, however, full thickness excision is required. For intermediate cases in which invasion of the viscera has penetrated the superficial layers but is not evident in the submucosa, opinion is divided. Early reports recommended an aggressive approach. More recently authors have tended to recommend less aggressive resections with postoperative adjuvant therapies. The role of external beam radiotherapy continues to evolve in DTC with support for its use in patients considered to have RAI-resistant tumors.

CONCLUSIONS

Patients with invasive DTC require a multidisciplinary approach to investigation and treatment. With detailed assessment, appropriate surgery, and adjuvant therapy when indicated, this patient group can expect durable control of central neck disease, despite the aggressive nature of their primary tumors.

Risk Factors for Recurrence in Filipinos with Well-Differentiated Thyroid Cancer

BACKGROUND

The incidence of well-differentiated thyroid cancer (WDTC) has increased in recent years. Despite its excellent prognosis, increasing morbidity from recurrent diseases continues to affect long-term outcomes. Among at-risk populations, Filipinos have the highest incidence of thyroid cancer worldwide, characterized by a highly aggressive and recurrent form of disease. Here, we sought to identify risk factors associated with disease recurrence among Filipinos with WDTC.

METHODS

This retrospective cohort study examined 723 patients diagnosed with WDTC seen at Philippine General Hospital. Affected individuals were classified based on the presence or absence of disease recurrence. Multivariate logistic regression analyses were used to determine significant predictors of recurrence.

RESULTS

Multiple risk factors, including age >45 years (odds ratio [OR], 1.44), multifocality of cancer (OR, 1.43), nodal involvement (OR, 4.0), and distant metastases at presentation (OR, 2.78), were significantly associated with a recurrence of papillary thyroid cancer (PTC). In contrast, follicular variant histology (OR, 0.60) and postsurgical radioactive iodine therapy (OR, 0.31) were protective for PTC recurrence. Distant metastases at presentation (OR, 19.4) and postsurgical radioactive iodine therapy (OR, 0.41) were associated with follicular thyroid cancer (FTC) recurrence.

CONCLUSION

Lymph node metastases at presentation was the strongest predictor of recurrence in PTC, whereas distant metastases at presentation was the strongest for FTC recurrence. Among Filipinos, stratification of WDTC patients based on recurrence risk factors identified in this study will be helpful in guiding the intensity of treatment strategies and long-term thyroid cancer surveillance.

Evolution in the profile of thyroid cancer cases treated in an oncology reference service: what changed in the last 20 years

Objective: To evaluate the characteristics of thyroid carcinoma cases treated at a reference hospital for cancer between 2008 and 2010.Methods: we studied 807 cases and analyzed the following clinicopathologic variables: symptoms, risk factors, diagnostic tests, staging, histological type, treatment performed and complications.Results: Females were more affected, with 660 cases (82%). The average age at diagnosis was 44.5 years. Prior exposure to ionizing radiation was reported by 22 (3%) patients, a family history of thyroid cancer by 89 (11%), and 289 (36%) individuals reported other types of cancer in the family. The fine needle aspiration biopsy was the main parameter for surgical indication and was suggestive of carcinoma in 463 patients (57%). Papillary carcinoma was the most common histological type, with 780 cases (96.6%). There were 728 (90%) total thyroidectomies, 43 (5.3%) reoperations or partial thyroidectomies followed by totalization, 23 (2.8%) extended thyroidectomies and only 13 (1.6%) partial thyroidectomies (lobectomy with isthmectomy). Neck dissection associated with thyroidectomy was done in 158 patients (19.5%). We observed a predominance of tumors classified as T1 in 602 (74.6%) patients. Transient hypocalcemia was the most frequent complication.Conclusion: The results show that the worldwide increase in the incidence of thyroid cancer has changed the profile of patients seen at a referral service. In addition, there were changes in the type of surgical treatment used, with increased use of total thyroidectomy in relation to partial and subtotal ones, and decreased use of elective neck dissections.

18-fluorodeoxyglucose positron emission tomography in the early diagnostic workup of differentiated thyroid cancer patients with a negative post-therapeutic iodine scan and detectable thyroglobulin

BACKGROUND

Surgery and high-dose radioactive iodine ((131)I) treatment are the cornerstones in the treatment of differentiated thyroid cancer. Patients without (131)I uptake on the post-therapeutic whole body scan (WBS), but with detectable thyroglobulin (Tg) during thyroxine withdrawal (Tg-off), are evaluated with an 18-fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET) for tumor localization within three months. The yield of (18)F-FDG-PET imaging and clinical usefulness of a Tg-off cutoff value to predict a positive scan were assessed.

METHODS

From 2002 to 2011, 52 patients with a negative WBS and concurrent detectable Tg-off were evaluated. Thirty-five PET scans were performed during initial treatment, 17 after recurrent disease. Thirty-two patients were on substitution therapy, 17 were evaluated with endogenous thyrotropin elevation, and 3 after recombinant human thyrotropin stimulation. To determine the Tg-off cutoff value, a receiver operating characteristic curve was used.

RESULTS

Nine (17%) (18)F-FDG-PET scans were true positive, 3 (6%) false positive, 36 (69%) true negative, and 4 (8%) false negative (sensitivity 69%, specificity 92%). In 13%, a true-positive scan resulted in a change in the clinical management. The area under the receiver operating characteristic curve is 0.82 [CI 0.64-0.99] (p<0.01), and the Tg-off cutoff value is 38.00 ng/mL (sensitivity 67%, specificity 95%). Ninety percent of (18)F-FDG-PET true-positive patients had a Tg-off >2.00 ng/mL.

CONCLUSIONS

An (18)F-FDG-PET within three months after a negative WBS with detectable Tg-off showed additional tumor localization in 17% of the patients, leading to a change in clinical management in 13%. A clinically useful Tg-off cutoff value was not found, but 90% of positive (18)F-FDG-PET scans occurred in patients with a Tg-off >2.00 ng/mL.