Factors contributing to unintentional parathyroidectomy during thyroid surgery.

Unintentional parathyroidectomy during thyroid surgery has an incidence ranging between 1% and 31% across institutions. Many studies have identified malignancy and central neck dissection as risk factors for losing parathyroid glands, but few studies have evaluated the impact of other factors such as lymphocytic thyroiditis, hyperthyroidism, or concomitant primary hyperparathyroidism. The purpose of this study was to investigate which factors contribute to parathyroid loss during thyroid surgery. Charts of 269 patients undergoing thyroid surgery at a tertiary care medical center from 2010 to 2013 were retrospectively reviewed. Sixty-six patients (24.5%) experienced unintentional parathyroidectomy. Bivariate analysis showed no significant differences in patient characteristics. Patients with unintentional parathyroid removal had a significantly smaller largest thyroid nodule size (P = 0.002), higher rate of central neck dissection (30.3% vs 7.9%, P < 0.0001), and higher rate of malignancy (50% vs 36.0%, P = 0.04). Multivariable analysis showed that the strongest risk factor for unintentional parathyroidectomy was central neck dissection (P = 0.0008; odds ratio 4.72, confidence interval 1.91-11.71). In conclusion, central neck dissection for thyroid malignancy is the strongest risk factor for unintentional thyroidectomy. The presence of concomitant primary hyperparathyroidism, lymphocytic thyroiditis, or hyperthyroidism did not appear to increase the risk of unintentional parathyroidectomy.

Degree of hypercalcemia correlates with parathyroidectomy but not with symptoms.

BACKGROUND: Primary hyperparathyroidism (HPT) is an undertreated disease. This study's purpose is to determine if the calcium levels correlate with prevalence of symptoms and surgical treatment in patients with primary HPT. METHOD: Patients treated in 2006-2015 with serum calcium≥10.0 mg/dL and PTH>65 pg/mL were identified and stratified based on calcium level: 10.0-10.3 (normocalcemia), 10.4-11.2 (moderate), and ≥11.3 (severe) mg/dL. Clinical variables and rates of surgery were compared between the three groups. RESULTS: A total of 2266 patients were identified: 303 with normocalcemia, 1513 with moderate hypercalcemia, and 450 with severe hypercalcemia. All three groups had similar rates of nephrolithiasis (p = 0.10), osteoporosis (p = 0.82), and reduced GFR (p = 0.06). Most patients (85%) had at least one surgical indication, but only 29% underwent parathyroidectomy. Higher calcium levels were correlated with higher surgical rates: 12% for Ca 10.0-10.3, 27% for Ca 10.4-11.2, and 46% for Ca≥11.3 (p < 0.01). CONCLUSION: Prevalence of symptoms does not correlate with calcium levels. Patients with normocalcemia and moderate hypercalcemia were equally likely to have a surgical indication, but normocalcemic patients are less likely to receive surgery.

Thyroid lobectomy is not sufficient for T2 papillary thyroid cancers.

BACKGROUND: Histologic subtypes of papillary thyroid cancer affect prognosis. The objective of this study was to examine whether survival is affected by extent of surgery for conventional versus follicular-variant papillary thyroid cancer when stratified by tumor size. METHODS: Using the National Cancer Data Base, we evaluated 33,816 adults undergoing surgery for papillary thyroid cancer from 2004 to 2008 for 1.0-3.9 cm tumors and clinically negative lymph nodes. Conventional and follicular-variant papillary thyroid cancers were divided into separate groups. Cox regression models stratified by tumor size were used to determine if extent of surgery affected overall survival. RESULTS: A total of 30,981 patients had total thyroidectomy and 2,835 had thyroid lobectomy; 22,899 patients had conventional papillary thyroid cancer and 10,918 had follicular-variant papillary thyroid cancer. On unadjusted KM analysis, total thyroidectomy was associated with improved survival for conventional (P = 0.02) but not for follicular-variant papillary thyroid cancer patients (P = 0.42). For conventional papillary thyroid cancer, adjusted analysis showed total thyroidectomy was associated with improved survival for 2.0-3.9 cm tumors (P = 0.03) but not for 1.0-1.9 cm tumors (P = 0.16). For follicular-variant, lobectomy and total thyroidectomy had equivalent survival for 1.0-1.9 cm (P = 0.45) and 2.0-3.9 cm (P = 0.88) tumors. CONCLUSION: Tumor size, histologic subtype, and surgical therapy are important factors in papillary thyroid cancer survival. Total thyroidectomy was associated with improved survival in patients with 2.0-3.9 cm conventional papillary thyroid cancer, and should be considered for 2.0-3.9 cm papillary thyroid cancers when preoperative molecular analysis is not used to distinguish conventional from follicular-variant.

CONCORDANCE OF PRE-OPERATIVE CLINICAL STAGE WITH PATHOLOGIC STAGE IN PATIENTS ≥45 YEARS OLD WITH WELL-DIFFERENTIATED THYROID CANCER.

OBJECTIVE: Clinical stage (cStage) in thyroid cancer determines extent of surgical therapy and completeness of resection. Pathologic stage (pStage) is an important determinant of outcome. The rate of discordance between clinical and pathologic stage in thyroid cancer is unknown. METHODS: The National Cancer Data Base was queried to identify 27,473 patients ≥45 years old with cStage I through IV differentiated thyroid cancer undergoing surgery from 2008-2012. RESULTS: There were 16,286 (59.3%) cStage I patients; 4,825 (17.6%) cStage II; 4,329 (15.8%) cStage III; and 2,013 (7.3%) cStage IV patients. The upstage rate was 15.1%, and the downstage rate was 4.6%. For cStage II, there was a 25.5% upstage rate. The change in cStage was a result of inaccurate T-category in 40.8%, N-category in 36.3%, and both in 22.9%. On multivariate analysis, the patients more likely to be upstaged had papillary histology, tumors 2.1 to 4 cm, total thyroidectomy, nodal surgery, positive margins, or multifocal disease. Upstaged patients received radioiodine more frequently (75.3% vs. 48.1%; P<.001). CONCLUSION: Approximately 20% of cStage is discordant to pStage. Certain populations are at risk for inaccurate staging, including cT2 and cN0 patients. Upstaged patients are more likely to receive radioactive iodine therapy. ABBREVIATIONS: CI = confidence interval; cStage = clinical stage; DTC = differentiated thyroid cancer; NCDB = National Cancer Data Base; OR = odds ratio; pStage = pathologic stage; RAI = radioactive iodine.

Minimally Invasive Adrenalectomy for Adrenocortical Carcinoma: Five-Year Trends and Predictors of Conversion.

BACKGROUND: Adrenocortical carcinoma (ACC) is rare but often fatal. Surgery offers the only chance of cure. As minimally invasive (MI) procedures for cancer become common, their role for ACC is still debated. We reviewed usage of MI approaches for ACC over time and risk factors for conversion using a large national database. METHODS: ACC patients with localized disease were identified in the National Cancer Data Base from 2010 to 2014. A retrospective review examined trends in the surgical approach over time. Patient demographics, surgical approach, and tumor characteristics between MI, open, and converted procedures were compared. RESULTS: 588 patients underwent adrenalectomy for ACC, of which 200 were minimally invasive. From 2010 to 2014, MI operations increased from 26 to 44% with robotic procedures increasing from 5 to 16%. The use of MI operations compared to open was not different based on facility type (p = 0.40) or location (p = 0.63). MI tumors were more likely to be confined to the adrenal (p < 0.001) but final margin status was not different (p = 0.56). Conversion was performed in 38/200 (19%). Average tumor size was 10.2 cm in the converted group compared to 8.6 cm in the MI group (p = 0.09). There was no difference in extent of disease (p = 0.33), margin status (p = 0.12), or lymphovascular invasion (p = 0.59) between MI and converted procedures. Tumor size > 5 cm was the only significant predictor of conversion (p = 0.04). No patients with pathologic stage I disease required conversion (0/19). CONCLUSIONS: The frequency of MI approaches for ACC is increasing. In the final year of the study, 44% of adrenalectomies were MI. Size > 5 cm was the only significant predictor of conversion.

Preoperative adrenal biopsy does not affect overall survival in adrenocortical carcinoma.

BACKGROUND: The impact of preoperative biopsy on overall survival (OS) in adrenocortical carcinoma (ACC) is unclear. We analyzed the National Cancer Data Base (NCDB) for factors associated with preoperative adrenal biopsy and its effect on OS in ACC. METHODS: The NCDB was queried from 2003 to 2012 for M0 ACC. Patients with or without preoperative biopsy were compared for factors associated with an increased rate of biopsy. Survival analysis was performed after adjusting for patient and tumor-related variables. RESULTS: There were 1782 patients with M0 ACC of whom 332 (19%) had a preoperative biopsy. Treatment outside academic cancer centers (OR 1.36, 95% CI 1.04-1.77, P = 0.023) and male gender (OR 1.45, 95% CI 1.11-1.88, P = 0.006) were associated with an increased rate of biopsy. In patients undergoing adrenalectomy with negative margins, biopsy failed to impact OS (log-rank P = 0.225, HR 1.20, 95% CI 0.84-1.72, P = 0.306). CONCLUSIONS: Preoperative adrenal biopsy continues to be performed for ACC with no added survival benefit. Adrenalectomy offers the best chance of survival in patients with ACC.