Factors influencing the outcome of patients with incidental papillary thyroid microcarcinoma

Value of surveillance ultrasound following hemithyroidectomy

BACKGROUND

There is limited evidence or agreement on the benefit, duration and frequency of post-operative surveillance neck ultrasound in patients with differentiated thyroid cancer treated with hemithyroidectomy alone. This study's primary aim was to assess the benefit of neck ultrasound in this situation, with a secondary aim to assess the detection of malignancy in the contralateral lobe in patients undergoing completion surgery.

METHODS

A retrospective observational study was conducted involving patients who had differentiated thyroid cancer found at diagnostic hemithyroidectomy between 1 December 2013 and 31 December 2016.

RESULTS

Of 105 patients, 74 underwent completion thyroidectomy. Thirty-five per cent of these patients had malignancy identified in the contralateral lobe, the majority were unsuspected sonographically. Of 31 hemithyroidectomy patients, 1 had a nodule classified as 'U3' (indeterminate) at the first ultrasound surveillance, ultimately identified as incidental papillary microcarcinomas on completion thyroidectomy. There was no other disease recurrence or malignancy at a median of 3.8 years' follow up.

CONCLUSION

The findings indicate a limited role for ultrasound follow up of patients with differentiated thyroid cancer treated with hemithyroidectomy alone.

Geriatric Importance of Histopathological Parameters Evaluated in Thyroidectomy Specimens: A Single Center Retrospective Analysis

Nowadays, the aging human population exerts a notable influence on the treatment of thyroid diseases. The most appropriate approach for the treatment of benign and malignant thyroid diseases in older adults has not yet been determined. The aim of our study is to evaluate the effect of thyroidectomies in geriatric patients considering age, sex and histopathological parameters and to determine the importance of thyroidectomy as a treatment option in the geriatric population. A total of 910 cases from all age groups were included, for which thyroidectomies were examined and reported. In accordance with the College of American Pathologists Cancer Protocol for thyroid reporting, considering geriatric patients, the rate of Thyroid Follicular Nodular Disease was significantly higher among the tumor types in the benign tumor group (p = 0.033), while Anaplastic Thyroid Carcinoma rate was higher in the malignant tumor group. The diagnosis rate of malignant tumors was higher in males, reflecting a more advanced pT stage (p < 0.001), larger tumor size (p < 0.001) and increased lymph node involvement rate (p = 0.039). Given that increasing age is associated with a heightened incidence of thyroid disease, the safety of surgery for geriatric patients is an important issue. Thyroidectomy should be considered in the treatment of these patients, especially in males, as the rate of malignant diagnosis and worse histopathological parameters are seen with increasing age.

Diagnostic Efficacy of Ultrasound, Cytology, and BRAFV600E Mutation Analysis and Their Combined Use in Thyroid Nodule Screening for Papillary Thyroid Microcarcinoma

Background

Ultrasound, cytology, and BRAF^V600E mutation analysis were applied as valuable tools in the differential diagnosis of thyroid nodules. The aim of the present study was to evaluate the diagnostic efficiency of the three methods and their combined use in screening for papillary thyroid microcarcinoma (PTMC).

Methods

A total of 1,081 patients with 1,157 thyroid nodules (0.5–1 cm in maximum diameter) classified as thyroid imaging reporting and data system (TIRADS) 4–5 were recruited. All patients underwent ultrasound, fine-needle aspiration (FNA) examination, and an additional BRAF^V600E mutation test. TIRADS and Bethesda System for Reporting Thyroid Cytopathology (BSRTC) were adopted to judge the ultrasound and cytological results. The receiver operating characteristic (ROC) curve was established to assess the diagnostic values of different methods.

Results

Of the 1,157 nodules, 587 were benign and 570 were PTMCs. BRAF^V600E mutation test had highest sensitivity (85.4%), specificity (97.1%), accuracy (91.4%), and area under the ROC curve (Az) value (0.913) among the three methods. The combination of BSRTC and BRAF^V600E mutation analysis yielded a considerably high sensitivity (96.0%), accuracy (94.3%), and negative predictive value (95.9%) than either BSRTC or BRAF^V600E mutation alone (P < 0.0001 for all comparisons). Of all the methods, the combined use of the three methods produced the best diagnostic performance (Az = 0.967), which was significantly higher than that (Az = 0.943) for the combination of BSRTC and BRAF^V600E mutation (P < 0.0001). The diagnostic accuracy of the molecular method in the 121 nodules with indeterminate cytology was 90.1% (109/121), which was significantly higher than that of TIRADS classification, 74.4% (90/121) (P = 0.002).

Conclusion

The combined use of ultrasound, cytology, and BRAF^V600E mutation analysis is the most efficient and objective method for diagnosing PTMC. Both BRAF^V600E mutation and TIRADS classification are potentially useful adjuncts to differentiate thyroid nodules, especially indeterminate samples classified as BSRTC III.

Prevalence and predictor for malignancy of contralateral thyroid nodules in patients with unilateral PTMC: a systematic review and meta-analysis

BACKGROUND

The presence of clinically negative nodules on the contralateral lobe is common in patients with unilateral papillary thyroid microcarcinoma (PTMC). The appropriate operational strategies of contralateral thyroid nodules remain controversial. In this study, we analyzed clinical features that could be predictors for malignancy of contralateral thyroid nodules coexisting with diagnosed unilateral PTMC.

METHODS

The literatures published from January 2000 to December 2019 were searched in PubMed, Cochrane Library, Embase, Web of Science, CNKI, and Wan Fang database. Odds ratio (OR) with 95% CI was used to describe categorical variables. Heterogeneity among studies was examined by the Q test and I2 test; potential publication bias was detected by Harbord test and 'trim and fill' method.

RESULTS

In this meta-analysis, 2541 studies were searched and 8 studies were finally included. The results showed that the rate of carcinoma in contralateral nodules was 23% (OR = 0.23, 95% CI = 0.18-0.29). The pooled data indicated that contralateral malignancy was not associated with age, gender, primary lesion size, ipsilateral central lymph node metastasis and multifocality of contralateral lesion. The following variables have correlations with an increased risk of contralateral malignancy: multifocality of primary carcinomas (OR = 3.93, 95% CI = 2.70-5.73, P < 0.0001), capsular invasion (OR = 1.61, 95% CI = 1.10-2.36, P = 0.01), and Hashimoto's thyroiditis (OR = 1.57, 95% CI = 1.13-2.20, P = 0.008).

CONCLUSIONS

Based on our meta-analysis, the rate at which contralateral malignancies are preoperatively misdiagnosed as benign is 23%. The risk factors for contralateral malignancy in unilateral PTMC patients with contralateral clinical negative nodules include multifocality of primary carcinomas, capsular invasion, and Hashimoto's thyroiditis.

Predictive Factors for Occult Bilateral Papillary Thyroid Carcinoma

BACKGROUND

Bilateral papillary thyroid carcinoma (PTC) requires aggressive treatment, such as total thyroidectomy (TT). If there is only an isolated PTC focus in one lobe that can be diagnosed preoperatively, and it is unknown whether there are foci in the contralateral lobe that are too small to be detected, it is difficult to know whether to perform TT or to remove only the lobe with the isolated PTC focus. Here, we investigated the prevalence of and predictive factors for occult bilateral PTC that was only diagnosed unilaterally before surgery.

METHODS

This retrospective study involved 586 patients with unilateral PTC who were diagnosed preoperatively by ultrasound. They underwent TT and cervical lymph node dissection. According to the pathology, they were divided into unilateral PTC and bilateral (Bil)-PTC groups. Student's t test, chi-squared test, and multivariate analysis were performed to identify features of the malignant tumor that increased the likelihood of malignancy in the contralateral lobe. The prevalence of occult Bil-PTC was calculated.

RESULTS

Bil-PTC was found in 70 of 586 (11.95%) PTC patients. Multivariate analysis showed that vascularity (odds ratio[OR]: 2.180, 95% confidence interval [CI]: 1.142-4.162, p = 0.018) and ultrasound diagnosis of lymph node metastasis (USLNM) (OR: 2.056, 95% CI: 1.056-4.004, p = 0.034) were independent predictors of occult Bil-PTC.

CONCLUSION

The prevalence of occult PTC in the contralateral lobe was only 11.95%. Vascularity and USLNM were risk factors for Bil-PTC. In terms of these preoperative risk factors for PTC, TT should be cautiously performed in patients with preoperative diagnosis of PTC with isolated focus.

Is Less More? A Microsimulation Model Comparing Cost-effectiveness of the Revised American Thyroid Association's 2015 to 2009 Guidelines for the Management of Patients With Thyroid Nodules and Differentiated Thyroid Cancer

OBJECTIVE

To assess relative clinical and economic performance of the revised American Thyroid Association (ATA) thyroid cancer guidelines compared to current standard of care.

BACKGROUND

Diagnosis of thyroid cancer in the United States has tripled whereas mortality has only marginally increased. Most patients present with small papillary carcinomas and have historically received at least a total thyroidectomy as a treatment. In 2015, the ATA released the revised guidelines recommending an option for active surveillance (AS) of small papillary thyroid carcinoma and thyroid lobectomy for larger unifocal tumors.

METHODS

We created a Markov microsimulation model to evaluate the performance of the ATA's 2015 guidelines compared to the ATA's 2009 guidelines. We modeled a cohort of simulated patients with demographic and thyroid nodule characteristics representative of those presenting clinically in the United States. Outcome measures include life expectancy, quality-adjusted life years, costs, and frequency of surgical adverse events.

RESULTS

In our base case analysis, the ATA 2015 strategy dominates the ATA 2009 strategy. The ATA 2015 strategy delivers greater discounted average quality-adjusted life years (13.09 vs 12.43) at a lower discounted average cost ($14,752 vs $20,126). Deaths due to thyroid cancer under the 2015 strategy are higher than the 2009 strategy but this is offset by a reduction in surgical deaths, leading to greater average life expectancy under the ATA 2015 strategy. The optimal strategy is sensitive to patients who experience a greater decrement in quality of life while undergoing AS.

CONCLUSIONS

The ATA 2015 Guidelines represent a cost-effective strategy regarding AS and extent of surgery.

A meta-analysis on the effect of operation modes on the recurrence of papillary thyroid microcarcinoma

Whether total thyroidectomy reduces the recurrence rate in patients with papillary thyroid microcarcinoma (PTMC) is currently controversy. Conclusions of sporadic, inconsistent, and mono-institutional studies need a meta-analysis to evaluate. 525 relevant studies were obtained from initial search on PubMed, 511 studies were excluded by inclusion and exclusion criteria. Eligible data were extracted from each included study. The Odds ratios (ORs) and 95% confidence interval (CI) were used to assess the difference in the recurrence rates between PTMC patients treated with total thyroidectomy and non-total thyroidectomy. OR and 95% CI were calculated using a fixed-effects or a random-effects model. The Q statistic was used to evaluate homogeneity and Beggs test was used to assess publication bias. 14 studies meeting the inclusion criteria were included in this meta-analysis. The over all recurrence rates of pooled patients with total thyroidectomy and non-total thyroidectomy were 2.83% and 2.84% respectively. Primary random-effects model analysis showed, no significant difference of recurrence rates existed between two operation modes (OR = 0.732, 95% CI: 0.444 - 1.208), while, high heterogeneity among studies was found, I-squared index (I2) = 40.2%. After remove one study with high heterogeneity, the OR of the pooled recurrence rates of the total thyroidectomy and the non-total thyroidectomy groups was 0.786 (95% CI: 0.363 - 1.701), further suggesting no significant difference of the recurrence rate exists between two operation modes. Our meta-analysis demonstrated postoperative recurrence of PTMC is not reduced by total thyroidectomy, non-total thyroidectomy is also a good choice to treat PTMC patients.

Clinical-pathological Characteristics and Prognostic Factors for Papillary Thyroid Microcarcinoma in the Elderly

Background: The incidence of papillary thyroid microcarcinoma (PTMC) has increased dramatically over the past three decades worldwide. The annual rate of increase in the elderly (≥65) PTMC patients is 1.4 times higher than that in the adult (<65) PTMC patients. The aim of the present study is to identify the clinical-pathological characteristics and prognostic factors in the elderly PTMC patients.

Methods: The source population is PTMC patients whose information is available in the Surveillance, Epidemiology and End Results (SEER) database (2004-2013). We analyzed specific selected clinical-pathological parameters and prognostic factors for the PTMC patients who were aged 65 or above (N=4812).

Results: Within the elderly group, the male patients, in comparison to the females, had a higher percentage of lymph-node metastases (5.29% vs. 12.27%, P < 0.001), distant metastasis (0.27% vs. 1.07%, P < 0.001), and stage III-IV tumors (9.19% vs. 15.85%, P < 0.001). Moreover, the elderly patients had a lower median cause-specific survival (CSS) compared with the adult patients (P < 0.001). Stage III-IV disease (hazard ratio (HR): 8.064, P < 0.001) was a strong risk factor for PTMC CSS. Being female (HR: 0.440, P = 0.011), total thyroidectomy (HR: 0.057, P = 0.001), and lobectomy (HR: 0.058, P < 0.001) were all strong protectors of PTMC CSS.

Conclusion: Thyroidectomy improved CSS of the elderly PTMC patients. Compared with thyroid lobectomy, total thyroidectomy did not increase CSS for the elderly PTMC patients. The elderly PTMC patients who received radio therapy did not experience an increase in CSS.

Relationships between clinicopathological prognostic factors in papillary thyroid microcarcinoma: a refined analysis based on 428 cases

A clear definition of the prognostic factors for papillary thyroid microcarcinoma (PTMC) is still debatable, as the tumor characteristics which indicate a high risk of metastasis are little known. We investigated the clinicopathological profile of a large group of PTMC, aiming to ascertain possible relationships between a set of clinicopathological characteristics and four parameters expressing tumor extension and aggressiveness (namely lympho-vascular invasion, thyroid capsule invasion, extrathyroidal extension and lymph node metastasis). For 428 patients, the following data were retrospectively documented: sex, age, tumor size, histological variant, associated thyroid pathology, location (subcapsular, intraparenchymal), unilateral or bilateral involvement, number of foci, lympho-vascular invasion, thyroid capsule invasion, extrathyroidal extension and lymph node metastasis. Data were analyzed using univariate and multivariate logistic regression analysis. Multivariate analysis confirmed that the tumor size is a negative prognostic factor for lympho-vascular invasion, thyroid capsule invasion, extrathyroidal extension and lymph node metastasis. We also demonstrated a strong relationship between the subcapsular location and lympho-vascular and capsule invasion, and extrathyroidal extension. The multifocality was correlated only with thyroid capsule invasion and extrathyroidal extension. Regarding the histological variants, the only validated correlation was between the oncocytic variant and extrathyroidal extension. Our work contributes to the validation of PTMC prognostic factors, useful in stratification of PTMC in high or low risk classes, and able to explain the behavioral differences in the tumor development.

Association of tumor size and focality with recurrence/persistence in papillary thyroid cancer patients treated with total thyroidectomy along with radioactive-iodine ablation and TSH suppression

Locoregional recurrence is common in papillary thyroid cancer PTC and an optimal surgical treatment with respect to the multifocal nature of the disease stays controversial. It is a retrospective analytical study design. 209 diagnosed PTCs managed at our institute were grouped into macro-PTC with a size of dominant focus >1 cm (unifocal n = 106 and multifocal n = 64) and micro-PTMC if size of all foci was <1 cm; (unifocal n = 16 and multifocal PTMC n = 23). The primary endpoint is recurrence and tumor free survival in each of the four groups. Secondary endpoint is an assessment of a benefit of completion total thyroidectomy in terms of assignment of true focal status to an individual's PTC. The median follow-up was 4.1 years. Upon completion thyroidectomy, the tumor focality changed to multifocal in 31.4% of macro-PTC and 60% of micro-PTMC. Multifocality was an independent risk factor for recurrence, OR 2.41 for macro (CI 1.14-5.11), and 3.48 for micro-multifocal PTMC (CI 1.19-10.2). Disease free survival patterns on Kaplan-Meier's plots were alike for micro- and macro-unifocal groups, and similarly stayed comparable among the two multifocal groups. Our analysis showed that tumor multifocality rather than size is the significant factor determining prognosis; hence, total thyroidectomy is indicated for an optimal assessment of true focality in micro-PTC.

Incidental Papillary Thyroid Microcarcinoma in an Endemic Goiter Area

Clinical and pathological characteristics of incidental papillary thyroid microcancer cases, surgical, medical, and nuclear treatment methods, and patients' outcome were studied during follow-up period of 102 months. We studied 37 patients with incidental papillary thyroid microcancer (I-PTM). The surgical procedure was total thyroidectomy in 29 and hemithyroidectomy in 8 patients. Size, multifocality, and bilateralism of PTM foci, thyroid capsule invasion, and presence of lymphovascular invasion were histopathological parameters. We analysed adjuvant medical and nuclear treatment and patients' outcome during follow-up period of 102 (61-144) months. The prevalence rates of I-PTM were 9.4% in 395 thyroidectomy cases. Histopathological examination reported unifocal disease in 30 and multifocal disease in 7 (18%) patients. Multifocal disease was bilateral in 6 (20.1%) patients. The mean size of the PTM foci was 4.88 mm. The rate of thyroid capsule invasion was 5.4%. All patients received a suppressive dose of LT4 to achieve a low serum TSH level. Adjuvant surgical and nuclear treatment was not performed in our cases. We did not find any negative changes in blood chemistry and ultrasound imaging, and any unfavourable events as locoregional and systemic recurrence. In conclusion, diagnosis of I-PTM is common that multifocality and bilateralism appear as pathologic features. The prognosis is excellent after surgical treatment and TSH suppression. Routine adjuvant nuclear treatment is unnecessary in majority of patients.

Hashimoto's Thyroiditis Does Not Affect Ultrasonographical, Cytological, and Histopathological Features in Patients with Papillary Thyroid Carcinoma

The association between papillary thyroid carcinoma (PTC) and Hashimoto's thyroiditis (HT) is controversial. In this study, we aimed to compare preoperative thyroid functions, ultrasonography (US) features, fine-needle aspiration biopsy (FNAB) results, and histopathological characteristics of PTC in patients with and without HT. Data of 919 PTC patients were reviewed retrospectively. The diagnosis of HT was based on histopathological examination and patients were grouped as HT and non-HT. There were 1321 PTC lesions in 919 patients among which 317 (34.5 %) had coexistent HT. There were no significant differences in nodule volume, longitudinal diameter, texture, echogenicity, marginal regularity, presence of microcalcification and hypoechoic halo, and peripheral vascularization in patients with and without HT (p > 0.05, for all parameters). Macrocalcification was observed more frequently in the non-HT group (p = 0.021). FNAB results were similar in the two groups (p = 0.105). Distribution of variants, capsule invasion, vascular invasion, and extrathyroidal extension were observed with similar rates in the HT and non-HT groups. Lymph node metastasis was significantly higher in patients without HT (p = 0.012). Of the carcinomas, 66.1 % (n = 874) were papillary thyroid microcarcinoma (PTMC). Tumor size was lower in PTMC lesions coexistent with HT (p = 0.026). We observed lower rates of capsule invasion, extrathyroidal extension, and lymph node metastases in PTMC with HT compared to without HT (p = 0.007, p = 0.003, and p = 0.015, respectively). This study showed that US features, FNAB results, and histopathological findings of PTC lesions are not influenced by the presence of HT. However, PTMC seems to be related with less aggressive histopathological behavior in HT.

Completion thyroidectomy: predicting bilateral disease

Introduction

It is not uncommon for patients with indeterminate thyroid nodules to undergo diagnostic hemithyroidectomy. When the final pathology determines that the nodule is in fact malignant, patients require counseling as to the whether a completion thyroidectomy is necessary.

Objectives

Determine the incidence of well differentiated thyroid cancer (WDTC) in the contralateral thyroid lobe in patients undergoing completion thyroidectomy.

Identify features of the malignant tumor in the initial resection that increase the likelihood of malignancy in the contralateral lobe.

Methods

Retrospective chart review of 97 patients who underwent hemithyroidectomy and completion thyroidectomy in a university’s teaching hospital network between 2006 and 2012. Pathology reports from both surgeries as well as patient and thyroid nodule characteristics were reviewed.

Results

Of the 97 patients, 47 (48 %) had a malignancy in the contralateral lobe. In the contralateral lobe, 42/47 (89 %) of malignancies were papillary microcarcinomas (PMC) and 15/42 (36 %) of the PMC were multifocal. Multifocal malignancies in the initial specimen had a 60 % rate of contralateral malignancy and were found to be a predictor of bilateral disease (p = 0.04) with OR = 2.74 (95 % CI: 1.11–6.79; p = 0.003) in WDTC and OR = 3.59 (95 % CI:1.35 9.48; p = 0.01) in papillary cancer specifically. There was no statistical significant correlation established for the following variables: presence of positive cervical nodes, extrathyroidal extension, positive resection margins, size and angio-lymphatic invasion. Moreover, there was no statistical correlation between any of the variants of papillary thyroid cancer and bilateral disease, even though most aggressive subtypes were found to be bilateral.

Conclusion

In this study, the rate of malignancy in the contralateral lobe was 48 %. Multifocality and presence of an aggressive subtype of papillary thyroid cancer in the initial specimen were found to be more important variables to consider in decision-making regarding completion thyroidectomy than size of the initial tumor alone.

Clinical characteristics of papillary thyroid microcarcinoma less than or equal to 5 mm on ultrasonography

Management of papillary thyroid microcarcinoma sized ≤5 mm identified on ultrasonography is controversial. In this study, we evaluated the clinical characteristics of papillary thyroid microcarcinoma sized ≤5 mm on ultrasonography in comparison to those >5 mm and sought to present rationales for optimal management in papillary thyroid microcarcinoma ≤5 mm. The medical records of 396 patients who underwent surgery for papillary thyroid carcinoma between 2009 and 2011 were retrospectively analyzed. The patients were grouped into A (≤5 mm, n = 132) or B (>5 mm, n = 264) and the clinicopathologic characteristics of the patients were reviewed and compared between the two groups. Tumor capsular invasion (45.5 vs. 59.8 %, p = 0.007) and cervical lymph node metastasis (18.2 vs. 29.2 %, p = 0.018) were more frequent in group B. Nonetheless, group A presented lymph node metastasis in 42.3 % of multifocal cases showing no difference to that of group B (41.5 %, p = 0.946) and also included five cases (3.8 %) of lateral neck metastasis. Multifocality was the only predictive factor for lymph node metastasis in group A (p < 0.001). Over half (55.3 %) of the patients of group A were diagnosed with papillary carcinoma in private clinics; however, only 5.5 % of these patients underwent assessment of lateral neck lymph nodes initially. In conclusion, higher risk of cervical lymph node metastasis should be considered in evaluation and surgical decision of papillary thyroid microcarcinoma ≤5 mm identified on ultrasonography with multifocality. Evaluation of the cervical lymph nodes including the lateral neck should not be overlooked when suspicious thyroid nodule suggesting malignancy sized ≤5 mm shows multifocal lesions.