Correlation between Central and Lateral Neck Dissection in Differentiated Thyroid Carcinoma

Objective: To determine the histopathological correlation between central and lateral neck metastasis in differentiated thyroid carcinoma, and its potential therapeutic impact. Although the central neck dissection (CND) is recommended in differentiated thyroid carcinoma, the indication for lateral neck dissection (LND) remains controversial. Design: Retrospective study. Methods and Main Outcome Measures: Pathological analysis of systematic ipsilateral central neck dissection (CND) and LND performed with total thyroidectomy in differentiated thyroid carcinoma was retrospectively reviewed according to “side” and to “patient”. Results: A total of 56 sides (46 patients) were suitable for analysis. Analysis by “side” revealed that CND and LND dissection samples were both negative in 15 cases, both positive in 32, CND was positive and LND was negative for 8 cases and CND was negative and LND was positive in 1 case. The combined presence of positive LND and positive CND was therefore observed in 32/40 “sides” and 26/46 “patients”. Analysis by “side” of the impact of the treatment decision to perform ipsilateral LND only in patients with positive CND and vice versa demonstrated a sensitivity, specificity, and accuracy of 97%, 65%, and 84%, respectively. Conclusions: In most cases, the presence of positive LND was associated with positive ipsilateral CND. The very low prevalence of positive LND in patients with negative CND may justify LND as a second step procedure only in patients with positive CND, except in the case of documented lateral neck metastasis.

The launch of a special issue on “Neck Dissection in Differentiated Thyroid Carcinoma” in Gland Surgery

Given the high incidence of cervical lymph node metastasis in differentiated thyroid cancer （DTC） and the rapidly increased importance of neck dissection in DTC, the journal of Gland Surgery is launching a special issue on ＂Neck Dissection in Differentiated Thyroid Carcinoma＂ in November Issue of 2013, inviting Dr. Xinying Li from Xiangya Hospital, China, as the guest editor.

Prevalence and Clinical Significance of Preoperative Thyroglobulin Antibodies in Differentiated Thyroid Cancer Patients

Thyroglobulin antibody (TgAb) has been used as a surrogate tumor marker of differentiated thyroid carcinoma (DTC) patients. Preoperative TgAb (PreopTgAb) is thought to affect the prevalence, disease severity, and outcome of DTC. The objective of the present study was to retrospectively analyze the prevalence of PreopTgAb in patients diagnosed with DTC and its relation to thyroid cancer characteristics, staging, and disease outcome. A retrospective analysis of 109 DTC patients with reports of PreopTgAb was carried out. Clinicopathological parameters, including patient demographics (age and gender), TNM staging, histopathologic characteristics (type of pathology, vascular invasion, extrathyroid extension, carcinoma variant, multifocality), treatment (surgery, radioactive iodine), and outcome were recorded. The association of PreopTgAb was compared with the study variables and outcome of the disease using the Chi-square test and Mann-Whitney tests. The prevalence of PreopTgAb was 59.6%. Among the 54 PreopTgAb positive patients, 34 patients had an excellent response and 15 patients had an indeterminate response, while biochemically and structurally incomplete response was observed in 3 and 2 patients, respectively. PreopTgAb was not significantly associated with age (p = 0.919), sex (p = 0.650), pathology (p = 0.079), stage at diagnosis (p = 0.513), vascular invasion (p = 0.211), extra thyroid extension (p = 0.734), histologic variant (p = 0.877), multifocality (p = 0.361), and outcome (p = 0.360). Although we did not find a significant association between positive PreopTgAb and clinical characteristics and outcome of DTC, it can still be considered as a surrogate marker of DTC during follow-up.

Comparison of Clinical and Ultrasonographic Features of Poorly Differentiated Thyroid Carcinoma and Papillary Thyroid Carcinoma

Background： The clinical behavior and management of poorly differentiated thyroid carcinoma （PDTC） are very different from papillary thyroid carcinoma （PTC）. By comparing the clinical and ultrasonographic features between the two tumors, we proposed to provide more possibilities for recognizing PDTC before treatment. Methods： The data of 13 PDTCs and 39 ageand gender-matched PTCs in Peking Union Medical College Hospital between December 2003 and September 2013 were retrospectively reviewed. The clinical and ultrasonic features between the two groups were compared. Results： The frequencies of family history of carcinoma, complication with other thyroid lesions, lymph node metastases, recurrent laryngeal nerve injuries, and distant metastases were higher in PDTCs （30.8%, 61.6%, 69.2%, 23.1%, and 46.2%, respectively） than those in PTCs （2.6%, 23.1%, 25.6%, 2.6%, and 2.6%, respectively） （P 〈 0.05）. The mortality rate of PDTCs was greatly higher than PTCs （P 〈 0.01）. Conventional ultrasound showed that the size of PDTCs was larger than that of PTCs （3.1±1.9 cm vs. 1.7± 1.0 cm）. Clear margins and rich and/or irregular blood flow were found in 92.3% of PDTCs, which differed substantially from PTCs （51.7% and 53.8%, respectively） （P 〈 0.05）. Conclusions： PDTC is more aggressive and its mortality rate is higher than PTCs. Accordingly, more attention should be given to suspicious thyroid cancer nodules that show large size, regular shape, and rich blood flow signals on ultrasound to exclude the possibility of PDTCs.

Postoperative Stimulated Thyroglobulin Level and Recurrence Risk Stratification in Differentiated Thyroid Cancer

Background： Postoperative preablative stimulated thyroglobulin （ps-Tg） has been evaluated in predicting prognosis and success of ablation regarding differentiated thyroid cancer （DTC）; however, its relationship with recurrence risk and radioiodine decision-making remains uncertain, especially in Chinese DTC patients. We aimed to evaluate the association between ps-Tg and recurrence risk stratification in DTC, to provide incremental values for ps-Tg in postoperative assessment and radioiodine management. Methods： Seven hundred and seven patients with DTC were included; low-risk （L; n = 90）, intermediate-risk （I; n = 283）, and high-risk （H; n = 334, 117 with distant metastasis [M 1 ]） patients were divided according to recurrence risk stratification. The M 1 group was further analyzed regarding evidence of metastasis. Cut-off values of ps-Tg were obtained using receiver operating characteristic analysis. Results： Patients with more advanced disease at initial risk stratification were more likely to have higher ps-Tg levels （I vs. L： P 〈 0.05; H vs. 1： P 〈 0.001; H vs. L： P 〈 0.001）. The corresponding cut-off value of ps-Tg for distinguishing sensitivity and specificity in each of the two groups was 2.95 ng/ml （1 vs. L： 61.5%, 63.3%）, 29.5 ng/ml （H vs, I： 41.9%, 92.6%）, 47.1 ng/ml （M1 vs. M0 in the H group： 79.5%, 88.9%） and 47.1 ng/ml （MI vs. M0 in all patients： 79.5%, 93.7%）. With the cut-offvalue at 47.1 ng/ml, ps-Tg was the only factor that could be used to identify distant metastases, and consequently if measured before radioiodine therapy would prevent 10.26% of patients with M1 from undertreatment, Conclusions： Ps-Tg, as an ongoing reassessment marker, favors differential recurrence risk grading and provides incremental values for radioiodine treatment decision-making.