Clinical Value of Lymph Node Ratio Integration with the 8th Edition of the UICC TNM Classification and 2015 ATA Risk Stratification Systems for Recurrence Prediction in Papillary Thyroid Cancer.

Recently, the 2015 American Thyroid Association (ATA) risk stratification and the 8th edition of the American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) TNM staging system were released. This study was conducted to assess the clinical value of the lymph node ratio (LNR) as a predictor of recurrence when integrated with these newly released stratification systems, and to compare the predictive accuracy of the modified systems with that of the newly released systems. The optimal LNR threshold value for predicting papillary thyroid cancer (PTC) recurrence was 0.17857 using the Contal and O'Quigley method. The 8th edition of the AJCC/UICC TNM staging system with the LNR and the 2015 ATA risk stratification system with the LNR were significant predictors of recurrence. Furthermore, calculation of the proportion of variance explained (PVE), the Akaike information criterion (AIC), Harrell's c index, and the incremental area under the curve (iAUC) revealed that the 8th edition of the TNM staging system with the LNR, and the 2015 ATA risk stratification system with the LNR, showed the best predictive performance. Integration of the LNR with the TNM staging and the ATA risk stratification systems should improve prediction of recurrence in patients with PTC.

Long-term oncologic outcomes of papillary thyroid microcarcinoma according to the presence of clinically apparent lymph node metastasis: a large retrospective analysis of 5,348 patients.

PURPOSE: Active surveillance (AS) of low-risk papillary thyroid microcarcinoma (PTMC) may reduce the risk of overtreatment of clinically insignificant cancer. However, the absence of predictor for the progression of PTMC resulted in treatment delay and potentially compromising cure of aggressive disease. Therefore, to anticipate potential damage of delayed surgery, we investigated the oncologic outcomes of patients with low-risk PTMC initially eligible for AS except clinically apparent lymph node metastasis (LNM), imitating delayed surgery with neck dissection. MATERIALS AND METHODS: A total of 5,348 patients, enrolled between 1987 and 2016, with low-risk PTMC initially eligible for AS were included regardless of LNM. We classified our study patients into two groups: Group I, lobectomy with prophylactic central cervical node dissection; Group II, total thyroidectomy with modified radical neck dissection for LNM. In addition, we investigated the oncological outcomes of patients with second-wave surgery due to lateral lymph node recurrence (Group III, subgroup of Group I). RESULTS: Group I showed more favorable clinicopathological characteristics compared with Group II. In Group I, only 29 (0.58%) of 4,927 patients underwent second-wave surgery with neck dissection for lateral lymph node recurrences, whereas in Group II, all 22 (5.23%) of 421 patients underwent second-wave selective node dissection because of nodal recurrence. Disease-free survival rates were significantly different between Groups I and II (P<0.05). Of note, the recurrence rate of Group II was still significantly higher than that of Group III (5.2% vs 0%, respectively; P=0.021). In addition, Kaplan-Mayer survival analysis indicated poor disease-free survival rates in Group II compared with Group III (P<0.05). CONCLUSION: The long-term treatment outcome of PTMC without LNM was favorable even if the recurrence occurs during follow-up period compared with that of PTMC with LNM. It should be noted that AS might be able to cause poor prognosis due to clinically apparent LNM.

Operative failure in minimally invasive parathyroidectomy utilizing an intraoperative parathyroid hormone assay.

BACKGROUND: Minimally invasive parathyroidectomy (MIP) is a targeted operation to cure primary hyperparathyroidism utilizing intraoperative parathyroid hormone monitoring (IOPTH). The purpose of this study was to quantify the operative failure of MIP. METHODS: Utilizing institutional parathyroid surgery database, demographic, operative, and biochemical data were analyzed for successful and failed MIP. Operative failure was defined as <6 months of eucalcemia after operation. RESULTS: Five hundred thirty-eight patients (96.6 %) had successful MIP with mean follow-up of 13 months, and 19 (3.4 %) had operative failure. The major cause of operative failure (11 of 19) was the result of surgeons' inability to identify all abnormal parathyroid glands. The remaining eight operative failures were the result of falsely positive IOPTH results. Eleven of 19 patients whose MIP had failed underwent a second parathyroid surgery. All but one of these patients achieved operative success, and 9 patients had missed multigland disease. Only 46 (8.3 %) of 557 patients had conversion to bilateral cervical exploration (BCE). Eighty percent of patients had more than 70 % IOPTH decrease, and all had successful operations. Patients with a marginal IOPTH decrease (50-59 %) had a treatment failure rate of 20 %. CONCLUSIONS: The most common cause of operative failure in MIP utilizing IOPTH was the result of surgeons' failure to identify all abnormal parathyroid glands. Falsely positive IOPTH is rare, and a targeted MIP utilizing IOPTH can achieve an excellent operative success rate without routine BCE. Selective BCE on patients with marginal IOPTH decrease may improve surgical outcome.

The role of thyroidectomy in metastatic disease to the thyroid gland.

BACKGROUND: Whether thyroidectomy for metastases to the thyroid is associated with a survival benefit remains debatable; in general, palliation and disease control are accepted goals in this setting. We evaluated the clinical features and overall survival of patients with thyroid metastasis treated by thyroid resection or nonoperatively. METHODS: This retrospective analysis included 90 patients identified with metastasis to the thyroid confirmed pathologically via thyroidectomy (n = 31) or fine-needle aspiration biopsy (n = 59). Overall survival was calculated by the Kaplan-Meier method, and differences between groups were calculated by Pearson's χ (2) coefficient. RESULTS: The most common primary malignancies were renal cell (20%), head and neck (19%), and lung (18%). The median time from primary tumor diagnosis to thyroid metastasis diagnosis was 37.4 months (range 0-210 months). Most metastases (69%) were metachronous, and 12% were isolated. The median follow-up after diagnosis of thyroid metastasis was 11.5 months (range 0-112 months). Median overall survival was longer in thyroidectomy patients compared to the fine-needle aspiration group (34 vs. 11 months, P < 0.0001). Patients with renal cell primary tumors were more likely to undergo thyroidectomy than patients with other primary tumors (78 vs. 24%, P < 0.0001). Nearly all patients with lung primary tumors died within 24 months of thyroid metastasis diagnosis, and thyroidectomy was only offered to three patients. CONCLUSIONS: Thyroidectomy was safe for selected patients with metastatic disease to the thyroid. Patients with metachronous or renal cell metastasis to the thyroid and whose primary tumor is/was treatable may be appropriate candidates for resection. Lung cancer metastasis to the thyroid is generally an ominous sign.

Long-term follow-up data may help manage patient and parent expectations for pediatric patients undergoing thyroidectomy.

BACKGROUND: We investigated the incidence and impact of postoperative complications in children who underwent total thyroidectomy (TTx). METHODS: The records of all pediatric patients undergoing TTx (2001-2011) at our institution were retrospectively reviewed for the occurrence of biochemical hypothyroidism (thyroid-stimulating hormone >10 mIU/mL), laboratory assessments, and medication nonadherence. RESULTS: The 74 patients (median age, 12.5 years) had thyroid cancer (differentiated, n = 39; medullary, n = 16) or benign pathology (n = 19; 16 with multiple endocrine neoplasia type 2A). The median postoperative follow-up was 3.2 years; 46 patients (62%) had ≥ 1 year follow-up. Forty-one percent had ≥ 1 period of medication nonadherence; this was not associated with age at TTx (P = .30). Non-treatment-related hypothyroidism occurred in 33% of patients during postoperative year (POY) 1. The number of POY1 laboratory assessments among the 30% of patients with parathyroid dysfunction was more than twice that among patients with normal parathyroid function (median assessments per year 8 vs 3; P < .0001). Forty-four percent of patients/families reported behavioral or physiologic changes; 40% were concomitant with abnormal thyroid function. CONCLUSION: More than 40% of pediatric patients were unable to fully adhere to postoperative medication regimens, and non-treatment-related hypothyroidism was common. Postoperative hypoparathyroidism doubled the number of laboratory assessments obtained. These data may help families better prepare for TTx sequelae.

Modern approach to surgical intervention of the thyroid and parathyroid glands.

Operative intervention on the parathyroid and thyroid glands has become more minimally invasive and selective over the past decade. This requires high-quality preoperative imaging evaluation for better knowledge of the relevant anatomical considerations and potential localization. Minimally invasive parathyroidectomy has become the operation of choice for most patients presenting with sporadic primary hyperparathyroidism (when the suspected parathyroid tumor is localized preoperatively). Preoperative imaging helps guide the surgeon as to which patients with thyroid pathology require intervention and the extent of resection. The imaging modalities reviewed include ultrasonography, technetium-99m sestamibi imaging, and four-dimensional computed tomography. Imaging modalities are discussed within the categories of benign and neoplastic parathyroid and thyroid pathology.