Reconfirmation of the accuracy of the taller-than-wide sign in multicenter collaborative research in Japan.

The taller-than-wide sign indicates that the anteroposterior dimension-to-transverse dimension ratio (AP/T ratio) is higher than 1. The aim of the present study was to reconfirm the accuracy of the taller-than-wide sign for diagnosing malignant thyroid nodules by ultrasonography in multicenter collaborative research, and investigate differences according to tumor sizes, histological types, and the influence of the tilt and orientation of the probe. At 6 registered institutes, 2,032 thyroid nodules were successively operated on and diagnosed pathologically. The accuracy of the taller-than-wide sign for diagnosing malignant tumors by ultrasonography was retrospectively analyzed across all nodules as well as in analyses separately stratified by tumor size and histology. The influence of the tilt and orientation of the probe was also assessed. The taller-than-wide sign showed high specificity for diagnosing malignancy in all nodules tested. It also showed high specificity regardless of the tumor size. When tumors were analyzed by histological types, the AP/T ratio of papillary carcinoma was significantly higher than that of benign nodules, whereas no significant difference was observed between follicular carcinoma and benign nodules. The specificity of longitudinal sections was significantly higher, while the AUC of longitudinal sections was significantly larger than those of transverse sections. The AP/T ratio obtained when the probe was tilted was not significantly different from that when it was straight. The present results support the usefulness of the taller-than-wide sign for diagnosing malignant tumors regardless of size, but not follicular carcinoma. The influence of the tilt and orientation of the probe was negligible.

Static Prognostic Factors and Appropriate Surgical Designs for Patients with Medullary Thyroid Carcinoma: The Second Report from a Single-Institution Study in Japan.

BACKGROUND: Medullary thyroid carcinoma (MTC) originates from calcitonin-producing cells of the thyroid. In 2009, we published our first report on the biological characteristics and prognosis of 118 MTC patients. Herein, we enrolled a larger number of patients with longer follow-up periods to further study the biological characteristics and appropriate therapies for MTC. METHODS: In general, hemithyroidectomy and total thyroidectomy were performed for sporadic MTC confined to the thyroid lobe and for hereditary MTC with central node dissection, respectively. Moreover, prophylactic modified radical neck dissection was performed on the side of macroscopic tumors. RESULTS: In total, 233 patients (99 hereditary and 134 sporadic) were enrolled. The median follow-up time was 128 months (range 7-445 months). Biochemical cure was obtained in 36 (62%) of the 58 patients who underwent prophylactic MND and were pathologically positive for lateral node metastasis. None of the patients had recurrence in the preserved thyroid. Distant recurrence was detected in 19 patients, and 12 died of MTC. Preoperative calcitonin and carcinoembryonic antigen levels, tumor size (T) > 4 cm, the male sex, clinical and pathological node metastases (N1), distant metastasis (M1), extrathyroid extension (Ex), and a lack of biochemical cure had prognostic impacts on distant recurrence and/or carcinoma-related mortality on univariate analysis. On multivariate analysis, Ex was independently correlated with distant recurrence, and Ex, T > 4 cm, and M1 independently affected carcinoma-related mortality. CONCLUSION: MTC patients had excellent prognosis in our institutions, indicating that our surgical strategies were appropriate.

Excellent Prognosis of Central Lymph Node Recurrence-Free Survival for cN0M0 Papillary Thyroid Carcinoma Patients Who Underwent Routine Prophylactic Central Node Dissection.

INTRODUCTION: In Japan, prophylactic central node dissection (p-CND) for papillary thyroid carcinoma (PTC) has been routinely performed in many institutions, including ours (Kuma Hospital, Japan). We evaluated the recurrence to a central lymph node in patients with cN0M0 PTC who underwent routine p-CND. MATERIALS AND METHODS: We enrolled 4301 patients with cN0M0 PTC who underwent an initial surgery between 1987 and 2005 (median age 51 years). The postoperative follow-up periods ranged from 4 to 362 months (median 164 months). Only 15 patients underwent radioactive iodine (RAI) ablation (≥30 mCi) after total or near total thyroidectomy. RESULTS: Of the 4301 patients with N0M0 PTC who underwent p-CND, 2548 (59%) were diagnosed as pN1a on postoperative pathological examination. To date, only 52 cases (1.2%) showed recurrence to a central lymph node. The 10-year and 20-year central node recurrence-free survival rates were excellent at 99.1 and 98.2%, respectively. On multivariate analysis, age ≥55 years, significant extrathyroid extension, tumor size >2 cm, and ≥5 pathologically confirmed central node metastases (but not the presence of central node metastasis) independently affected central node recurrence. CONCLUSIONS: Under the situation of routine p-CND, the central node recurrence-free survival of cN0M0 PTC is excellent. However, future studies, including double-arm studies from Japan, should examine whether the omission of p-CND cN0M0 PTC is appropriate without RAI ablation in consideration of various factors, including the pros and cons of p-CND.

Overall Survival of Papillary Thyroid Carcinoma Patients: A Single-Institution Long-Term Follow-Up of 5897 Patients.

INTRODUCTION: Papillary thyroid carcinoma (PTC) generally shows an excellent prognosis except in cases with aggressive backgrounds or clinicopathological features. Although the cause-specific survival (CSS) of PTC patients has been extensively investigated, the overall survival (OS) of these patients is unclear. We herein investigated both the OS and CSS of a large PTC patient series. MATERIALS AND METHODS: We enrolled 5897 PTC patients who underwent initial surgery between 1987 and 2005 (658 males and 5339 females; median age 51 years). Their median postoperative follow-up period was 177 months. Univariate and multivariate analyses for OS and CSS assessed the effects of gender, older age (≥55 years), distant metastasis at diagnosis (M1), significant extrathyroid extension, tumor size (cutoffs 2 and 4 cm), large node metastasis (N ≥ 3 cm), and extranodal tumor extension. RESULTS: To date, 387 patients (7%) in this series have died from various causes, including 117 (2%) due to PTC. The 10-, 15-, and 20-year OS rates are 97, 95, and 90%, respectively. Older age and M1 were important prognostic factors for OS and CSS. Older age was a more significant factor than M1 for OS and vice versa for CSS. In the older patients, M1 was a prominent prognostic factor for both OS and CSS. In the young patients, M1 had less prognostic impact than in the older patients, and the prognostic values of M1 and N ≥ 3 cm for OS and CSS were identical and similar, respectively. CONCLUSIONS: The most important prognostic value for OS was patient age, indicating that PTC is generally indolent. However, the control of distant metastasis in older patients remains a future challenge in order to further improve their OS and CSS. PTC of ≥3 cm in young patients should be carefully followed, even in the absence of metastases, and these patients should undergo aggressive therapies for recurrent lesions and metastases.

Thyroid sclerosing mucoepidermoid carcinoma with eosinophilia distinct from the salivary type.

We report three cases of thyroid sclerosing mucoepidermoid carcinoma with eosinophilia (SMECE), which is an extremely rare variant of mucoepidermoid carcinoma (MEC). The aims of this report were to describe the clinicopathological findings, including results from immunohistochemical and fluorescence in situ hybridization analysis of thyroid SMECE, as well as to discuss the distinction between thyroid SMECE and its salivary counterpart. The cases included a 63-year-old female, a 44-year-old male, and a 66-year-old female, with all patients presenting with Hashimoto's thyroiditis. Nodal metastasis was not found in any of the three cases. Neither regional recurrences nor distant metastases were found in any patient during the follow-up, which was 20 years, 3 years, and 18 months, respectively. Histologically, tumors were composed of epidermoid carcinoma cells, intermediate type carcinoma cells, and goblet cell-type mucus-secreting carcinoma cells, with all tumors displaying a sclerotic stroma with eosinophilic and lymphocytic infiltration. The formation of eosinophilic abscess in the tumor nests that might be a novel characteristic finding of SMECE was observed. Immunohistochemically, the carcinoma cells were positive for cytokeratin 34ßE12, TTF-1, and PAX8, but negative for thyroglobulin. In two cases, increased IgG4-positive plasma cells were observed. Mastermind-like transcriptional coactivator 2 (MAML2), according to fluorescence in situ hybridization, was intact in all cases. In conclusion, thyroid SMECE has favorable outcomes and seems to be genetically different from salivary MEC. This is the first report to describe the presence of increased IgG4-positive plasma cells in the stroma of SMECE.

Prognostic value of the 8th tumor-node-metastasis classification for follicular carcinoma and poorly differentiated carcinoma of the thyroid in Japan.

Follicular thyroid carcinoma (FTC), a form of differentiated thyroid carcinoma, is the second most common malignancy arising from thyroid follicular cells. Recently, the tumor-node-metastasis (TNM) classification for differentiated thyroid carcinoma was revised from the 7th to the 8th edition. The diagnostic criteria for poorly differentiated carcinoma (PDC) were also updated in the latest World Health Organization (WHO) classification. In this study, we investigated whether these changes are appropriate for accurately predicting prognosis. Three hundred and twenty-nine patients diagnosed with postoperative pathologically confirmed FTC, who underwent initial surgery at our hospital between 1984 and 2004, were enrolled. For this study, patients were re-evaluated and diagnosed with FTC (N = 285) or PDC (N = 44) without typical nuclear findings of papillary thyroid carcinoma. For FTC, the 8th TNM classification was a more accurate predictor of prognosis than the 7th TNM classification. In the 8th TNM classification, cause-specific survival became significantly poorer from Stage I to IVB. The cause-specific survival of PDC based on the latest WHO classification was worse than, but did not significantly differ from, that of PDC based only on the former WHO classification. For PDC, neither of the TNM classifications could accurately predict prognosis. Taken together, we conclude that (1) the 8th TNM classification more accurately reflects the prognosis of FTC than the 7th TNM classification; (2) PDC based on the former WHO classification should be retained, at least in Japan; and (3) the TNM classification may not be suitable for predicting the prognosis of PDC.

Prognostic value of the 8th edition of the tumor-node-metastasis classification for patients with papillary thyroid carcinoma: a single-institution study at a high-volume center in Japan.

The tumor-node-metastasis (TNM) staging system is most commonly adopted to evaluate the prognosis of patients with thyroid carcinoma. The 8th edition of the TNM staging system, an extensively revised version of the 7th edition, was recently released. We aimed to investigate whether and how well the 8th edition reflects the cause-specific survival (CSS) of patients with papillary thyroid carcinoma by analyzing the cases in 5,892 patients who underwent initial surgery at Kuma Hospital between 1987 and 2005. The median postoperative follow-up duration was 178 months (range: 6-357 months). One patient with T4b disease was excluded from the analysis. Overall, 116 (2.0%) patients died of thyroid carcinoma. The proportion of variance explained (PVE) for CSS in the 7th and 8th editions was 10.69 and 10.97, respectively. Using the 7th edition, CSS of patients with stage IVA and stage III disease was similar (p = 0.32). In contrast, using the 8th edition, CSS was poorer in stage II than in stage I (p < 0.001), in stage III than in stage II (p < 0.001), and in stage IVB than in stage III (p < 0.001). Similar results were observed for disease-free survival. Although we could not establish any objective evidence that the 8th edition is superior to the 7th edition, the 8th edition is simpler and more convenient, as it includes fewer stages and addresses the issue of the 7th edition where stage IVA and III patients had similar prognoses.

The Effectiveness of Prophylactic Modified Neck Dissection for Reducing the Development of Lymph Node Recurrence of Papillary Thyroid Carcinoma.

AIM: The most frequent recurrence site of papillary thyroid carcinoma (PTC) is the cervical lymph nodes. The introduction of an electric linear probe for use with ultrasonography in 1996 improved preoperative lateral neck evaluations. Before 2006, however, our hospital routinely performed prophylactic modified neck dissection (p-MND) for N0 or N1a PTCs >1 cm to prevent node recurrence. In 2006, we changed our policy and the indications for p-MND to PTCs >3 cm and/or with significant extrathyroid extension. Here, we retrospectively compared lymph node recurrence-free survival between PTCs with/without p-MND. METHODS: We examined the cases of N0 or N1 and M0 PTC patients who underwent initial surgery in 1992-2012. To compare lymph node recurrence-free survival between patients who did/did not undergo p-MND, we divided these patients into three groups (excluding those whose surgery was in 2006): the 2045 patients whose surgery was performed in 1992-1996 (Group 1), the 2989 with surgery between 1997 (post-introduction of ultrasound electric linear probes) and 2005 (Group 2), and the 5332 operated on in 2007-2012 (Group 3). RESULTS: The p-MND performance rate of Group 3 (9%) was much lower than that of Group 1 (80%), but the lymph node recurrence-free survival of the former was significantly better, probably due to differences in clinical features and neck evaluations by ultrasound between the two groups. Our analysis of the patients aged <75 years with 1.1-4-cm PTCs in Groups 2 and 3 showed that p-MND did not improve lymph node recurrence-free survival. p-MND did significantly improve lymph node recurrence-free survival for the extrathyroid extension-positive 3.1-4-cm PTCs, but not for the other subsets. CONCLUSIONS: Abolishing routine p-MND for PTCs in 2006 did not decrease lymph node recurrence-free survival, probably due to improved ultrasound preoperative neck evaluations and clinical feature changes. Selective p-MND for high-risk cases improved lymph node recurrence-free survival.

Comparison of the costs of active surveillance and immediate surgery in the management of low-risk papillary microcarcinoma of the thyroid.

The incidence of thyroid cancer is increasing rapidly in many countries, resulting in rising societal costs of the care of thyroid cancer. We reported that the active surveillance of low-risk papillary microcarcinoma had less unfavorable events than immediate surgery, while the oncological outcomes of these managements were similarly excellent. Here we calculated the medical costs of these two managements. We created a model of the flow of these managements, based on our previous study. The flow and costs include the step of diagnosis, surgery, prescription of medicine, recurrence, salvage surgery for recurrence, and care for 10 years after the diagnosis. The costs were calculated according to the typical clinical practices at Kuma Hospital performed under the Japanese Health Care Insurance System. If conversion surgeries were not considered, the 'simple cost' of active surveillance for 10 years was 167,780 yen/patient. If there were no recurrences, the 'simple cost' of immediate surgery was calculated as 794,770 yen/patient to 1,086,070 yen/patient, depending on the type of surgery and postoperative medication. The 'simple cost' of surgery was 4.7 to 6.5 times the 'simple cost' of surveillance. When conversion surgeries and recurrence were considered, the 'total cost' of active surveillance for 10 years became 225,695 yen/patient. When recurrence were considered, the 'total cost' of immediate surgery was 928,094 yen/patient, which was 4.1 times the 'total cost' of the active surveillance. At Kuma Hospital in Japan, the 10-year total cost of immediate surgery was 4.1 times expensive than active surveillance.

Surgical Methods and Experiences of Surgeons did not Significantly Affect the Recovery in Phonation Following Reconstruction of the Recurrent Laryngeal Nerve.

BACKGROUND: We reported phonatory recovery in the majority of 88 patients after recurrent laryngeal nerve (RLN) reconstruction. Here we analyzed factors that might influence the recovery, in a larger patient series. METHODS: At Kuma Hospital, 449 patients (354 females and 95 males) underwent RLN reconstruction with direct anastomosis, ansa cervicalis-to-RLN anastomosis, free nerve grafting, or vagus-to-RLN anastomosis; 47.4 % had vocal cord paralysis (VCP) preoperatively. Maximum phonation time (MPT) and mean airflow rate during phonation (MFR) were measured 1 year post surgery. Forty patients whose unilateral RLNs were resected and not reconstructed and 1257 normal subjects served as controls. RESULTS: Compared to the VCP patients, the RLN reconstruction patients had significantly longer MPTs 1 year after surgery, nearing the normal values. The MFR results were similar but less clear. Detailed analyses of 228 female patients with reconstruction for whom data were available revealed that none of the following factors significantly affected phonatory recovery: age, preoperative VCP, method of reconstruction, site of distal anastomosis, use of magnifier, thickness of suture thread, and experience of surgeon. Of these 228 patients, 24 (10.5 %) had MPTs <9 s 1 year after surgery, indicating insufficient recovery in phonation. This insufficiency was also not associated with the factors mentioned above. CONCLUSIONS: Approximately 90 % of patients who needed resection of the RLN achieved phonatory recovery following RLN reconstruction. The recovery was not associated with gender, age, preoperative VCP, surgical method of reconstruction, or experience of the surgeon. Performing reconstruction during thyroid surgery is essential whenever the RLN is resected.

Diagnosis and surgical indications of oxyphilic follicular tumors in Japan: Surgical specimens and cytology.

Oxyphilic cell carcinoma is a relatively rare type of differentiated thyroid carcinoma. We investigated the diagnosis of oxyphilic cell carcinoma based on surgical specimens and cytology to elucidate the indications for surgery for oxyphilic tumors. Among 330 patients pathologically diagnosed as having an oxyphilic cell carcinoma or adenoma, the incidence of carcinoma was 21%. The pathological diagnosis of oxyphilic cell carcinoma was related to tumor size (>4 cm). On cytology, 79% of the tumors were classified as category IV or greater by the Bethesda System for Reporting Thyroid Cytopathology (BSRTC), but no significant difference was established between category IV or greater and categories I-III regarding the incidence of carcinoma. Of 998 patients cytologically diagnosed as having oxyphilic cell tumors (BSRTC category IV), 426 underwent surgery and 66 (15%) were diagnosed as malignancies. In a univariate analysis, serum thyroglobulin (Tg) levels (>500 ng/dL) for anti-Tg antibody-negative patients, tumor size (>4 cm) and US class (≥3) significantly predicted malignant histology. A multivariate logistic analysis revealed that US finding was an independent predictor of malignant histology, and tumor size (>4 cm) also predicted malignancy when the Tg level was excluded from the variables. These findings suggest that, for thyroid tumors diagnosed as oxyphilic follicular neoplasms on cytology, surgical indications are tumors with US class ≥3, tumor size >4 cm, and Tg >500 ng/dL (with negative Tg-antibody). It is not appropriate to perform surgery for all cases for a precise histological classification, unlike the BSRTC recommendation.

Prognostic impact of Ki-67 labeling index in minimally invasive follicular thyroid carcinoma.

We investigated the prognostic impact of the Ki-67 labeling index (LI) in minimally invasive follicular thyroid carcinoma (FTC). We enrolled 192 patients (including four with distant metastasis at diagnosis) who were pathologically diagnosed as having minimally invasive FTC between 1998 and 2007 at Kuma Hospital. When the Ki-67 LI was higher than 5% in the hot area, we regarded it as a high Ki-67 LI. In a univariate analysis, patient age (≥45 years), high-frequent vascular invasion (≥4 in H&E specimens), and high Ki-67 LI significantly predicted the disease-free survival (DFS) of the patients. Since none of the patients <45 years old showed a recurrence, we performed a multivariate analysis of variables other than patient age. In the multivariate analysis including the presence of vascular invasion, high Ki-67 LI was an independent predictor of carcinoma recurrence. However, in the multivariate analysis including high-frequent vascular invasion, only high-frequent vascular invasion independently affected the DFS. These findings suggest that the Ki-67 LI has a rather strong prognostic value for the DFS of patients, although its impact was less than those of patient age and high-frequent vascular invasion.

Changes in serum thyroglobulin antibody levels as a dynamic prognostic factor for early-phase recurrence of thyroglobulin antibody-positive papillary thyroid carcinoma after total thyroidectomy.

We demonstrated previously that dynamic prognostic markers such as the thyroglobulin (Tg)-doubling time in thyroglobulin antibody (TgAb)-negative papillary thyroid carcinoma (PTC) and changes in pre- and postoperative TgAb levels in TgAb-positive PTC patients more keenly reflect patients' prognosis than conventional static prognostic factors. Here we investigated periodic changes in TgAb levels in 513 TgAb-positive PTC patients who underwent total thyroidectomy. The TgAb levels at 1 year after surgery decreased to <50% of the preoperative values in 407 (79%) patients, and the remaining 106 (21%) patients showed no decrease in TgAb. In 426 patients, TgAb was also measured more than 1 year after surgery. Compared with their TgAb levels 1 year after surgery, 59 patients (14%) showed an increase in TgAb levels of >20% during the follow-up. The postoperative Tg levels at 1 year after surgery remained positive in 44 (9%) patients despite their TgAb positivity. To date (median follow-up period 35 months), 12 of the 426 patients (3%) showed PTC recurrence, and 11 of these patients showed either or both a TgAb elevation later than 1 year after surgery and postoperative Tg positivity. Although further studies with longer follow-ups are necessary, we can conclude that changes in postoperative TgAb levels may be usable as a surrogate tumor marker for TgAb-positive PTC patients after total thyroidectomy.

Prognosis and prognostic factors of differentiated thyroid carcinoma after the appearance of metastasis refractory to radioactive iodine therapy.

Differentiated thyroid carcinomas (DTCs) are generally indolent, but few therapeutic strategies are available after a metastatic recurrence that is refractory to radioactive iodine (RAI) therapy. Molecular-target therapy has shown promising results for DTCs with RAI-refractory recurrence. However, not all RAI-refractory recurrences are progressive, and even those that are progressive may not be immediately life-threatening. Here we investigated the prognosis and prognostic factors of 74 DTC patients (52 females, 22 males) in whom RAI-refractory metastases appeared. The five-year and 10-year cause-specific survival (CSS) rates of the 74 patients (8-82 yrs of age; median age at the detection of metastases, 61 yrs) were 95% and 70%, respectively, and the older patients (≥ 60 yrs, n=38) and male patients were significantly more likely to die of carcinoma. Also in multivariate analysis, older age (≥ 60 years) and male gender were independent predictors of carcinoma-related death. Taken together, our data indicate that RAI-refractory metastases of older patients and male patients are more progressive than those of other patients. Further studies are necessary to clarify the appropriate indications for molecular-target therapy for RAI-refractory and progressive metastases.

Tumor size is the strongest predictor of microscopic lymph node metastasis and lymph node recurrence of N0 papillary thyroid carcinoma.

It is well-known that papillary thyroid carcinoma (PTC) frequently metastasizes to the regional (central and lateral) lymph nodes, even though it is diagnosed as node-negative on preoperative imaging studies. In this study, we investigated predictors of microscopic node metastasis and lymph node recurrence of PTC without node metastasis detected preoperatively (N0). Of the clinicopathological features that can be evaluated pre- and intraoperatively, tumor size (> 2 cm) was the strongest predictor of microscopic central and lateral node metastasis on multivariate logistic analysis. Also, the tumor size most markedly affected lymph node recurrence, but not distant recurrence. Lymph node recurrence may not be immediately life-threatening, but it can be a stressor both for physicians and patients. Therefore, careful lymph node dissection is recommended for PTC with a large size, even though it is prophylactic.

Incidence and predictors of right paraesophageal lymph node metastasis of N0 papillary thyroid carcinoma located in the right lobe.

Papillary thyroid carcinoma (PTC) frequently metastasizes to the regional lymph nodes and, thus, guidelines edited by Japan Association of Endocrine Surgeons/Japanese Society of Thyroid Surgery routinely recommend central node dissection even for patients with no clinically detectable node metastasis (N0). However, in the central compartment, metastasis to the right paraesophageal node has not been intensively investigated. We investigated the incidence and predictors of right paraesophageal node metastasis based on pre- and intraoperative findings in 922 patients with N0 PTC in the right lobe. Fourteen percent of patients were microscopically positive for right paraesophageal node metastasis, and the incidence was smaller than that for pre- and right paratracheal node metastasis (46%). On multivariate analysis, a tumor size ≥ 2 cm and significant extrathyroid extension were independent predictors of metastasis. Microscopically pre- and right paratracheal node-positive PTC more often (p < 0.0001) metastasized to the right paraesophageal node. Taken together, in N0 PTC in the right lobe, right paraesophageal node dissection should be considered in tumors 2 cm or larger and/or with significant extrathyroid extension, or when pre- and right paratracheal node metastasis is suspected based on the intraoperative findings.

Distant metastasis at diagnosis and large tumor size are significant prognostic factors of widely invasive follicular thyroid carcinoma.

In contrast to minimally invasive follicular thyroid carcinoma (FTC), widely invasive FTC is aggressive and is associated with a dire prognosis. However, prognostic factors of widely invasive FTC have not been intensively investigated. In this study, we investigated this issue in a series of 79 widely invasive FTC patients. In the subset of 70 patients who did not show distant metastasis at diagnosis (M0), only a tumor size larger than 4 cm had a prognostic impact on disease-free survival (DFS) both on uni- and multivariate analyses. Regarding the cause-specific survival (CSS) of 79 patients, only distant metastasis at diagnosis (M1) had a significant prognostic value on uni- and multivariate analyses. None of the 70 M0 patients with a tumor measuring 4 cm or less died of FTC. Other clinicopathological features such as age, gender, and oxyphilic carcinoma were of no prognostic value. These findings suggest that 1) M1 is the strongest prognostic factor for CSS of widely invasive FTC patients, and 2) a tumor size larger than 4 cm significantly affects the DFS and CSS of M0 patients. Aggressive therapies with careful follow-up are recommended, especially for these patients.

Prognostic significance of changes in serum thyroglobulin antibody levels of pre- and post-total thyroidectomy in thyroglobulin antibody-positive papillary thyroid carcinoma patients.

Although postoperative serum thyroglobulin (Tg) is a prognostic indicator for papillary thyroid carcinoma (PTC), it is unreliable when Tg antibody (TgAb) is positive. We evaluated the prognostic significance of changes in serum TgAb levels of pre- and post-total thyroidectomy in TgAb-positive PTC patients. We reviewed our medical charts of 225 TgAb-positive PTC patients in whom TgAb levels were measured before and 1-2 years after total thyroidectomy, performed between April 2002 and March 2007. We divided them into 3 groups based on changes in TgAb levels. Postoperative serum TgAb levels decreased by ≥ 50% in 181 patients (80.4%) (Group 1), by <50% in 22 patients (9.8%) (Group 2), and increased in 22 patients (9.8%) (Group 3). During the follow-up, 3 patients died of the disease and 14 patients had recurrences. All 3 patients who died of PTC were seen only in Groups 2 and 3. Groups 2 and 3 showed similar prognostic outcomes, thus were analyzed together as Group 2+3. Group 1 had significantly better lymph node recurrence-free survival and distant recurrence-free survival than Group 2+3 (96.9% vs. 90.5%, p <0.001, and 98.9% vs. 90.1%, p = 0.004, respectively at 5 years). Multivariate analyses on prognostic factors revealed that classification to Group 2+3 was the strongest indicator for poor prognosis. The present results suggest that changes in TgAb levels following total thyroidectomy can be an important dynamic prognostic factor of PTC patients. Prospective periodical measurements of TgAb are necessary to confirm these findings.

The ima approach for the quick identification of the right recurrent laryngeal nerve in thyroid cancer surgery.

BACKGROUND: The right recurrent laryngeal nerve (RLN) is more difficult to identify than the left RLN. The superior, lateral and inferior approaches are currently used to identify the RLN. This report presents a new technique, called the ima approach (the most inferior approach) for the quick identification of the right RLN. METHODS: The ima approach involves dissection along the right common carotid artery and division of the most lateral branch of the inferior thyroid veins. The right RLN is identified at the bottom of the RLN triangle. This technique and the conventional inferior approach were applied to 81 and 19 patients with thyroid cancer, respectively. RESULTS: The ima approach required a significantly shorter time in identifying the nerve than the inferior approach (9.6 ± 16.6 and 31.2 ± 24.4 s, respectively, p < 0.0001). CONCLUSION: The ima approach is an easy, quick and safe technique for identifying the right RLN.

Investigation of the prognosis of patients with papillary thyroid carcinoma by tumor size.

In papillary thyroid carcinoma (PTC), extrathyroid extension (Ex) and clinical lymph node metastasis (N) significantly affect the prognosis. We investigated the prognosis of patients with PTC 1 cm or less (1,220 patients), 1.1-2 cm (2,101 patients), 2.1-3 cm (1,249 patients), 3.1-4 cm (645 patients), and larger than 4 cm (563 patients). We classified N factor into three categories: N0, no clinical node metastasis: N1, clinical node metastasis smaller than 3 cm and without extranodal tumor extension requiring at least partial excision of adjacent organs for node dissection: and N2, clinical node metastasis 3 cm or larger or showing extranodal tumor extension. N2 markedly affected lymph node and distant recurrence-free survivals and cause-specific survival, regardless of the tumor size. N1 also adversely affected lymph node and distant recurrence-free survival but not cause-specific survival. Ex did not affect patients' prognosis with PTC 1 cm or less. It became a prognostic factor with PTC larger than 1 cm, and worsened lymph node and distant recurrence-free survival not only for N0 but also for N1 PTC larger than 3 cm and larger than 2 cm, respectively. However, its influence is limited for N2 PTC patients. Furthermore, Ex worsened the CSS with PTC larger than 2 cm in combination with N2. We have to note that the prognostic significance for lymph node and distant recurrence-free and cause-specific survival of Ex and N varies according to the tumor size in order to accurately predict the clinical outcomes and establish therapeutic strategies for PTC patients.