Age and Post-Lobectomy Recurrence after Endoscopic or Robotic Thyroid Surgery: A Retrospective Cohort Study of 2348 Papillary Thyroid Carcinoma Patients.

The biology of papillary thyroid carcinoma (PTC) in young patients is poorly understood, and there are conflicting data regarding the recurrence for younger patients compared to older patients. We retrospectively analyzed 2348 clinically node-negative (cN0) PTC patients who underwent a thyroid lobectomy between 2008 and 2017. Young age was defined as less than 35 years old. The clinicopathological characteristics and oncologic outcomes of the young age group were compared to those of the older age group. The number of young age cN0 PTC patients accounted for 20.7% of the enrolled patients, and 24.2% were upstaged into pathologic N1a. The young age group had a significantly larger proportion of females, endoscopic/robotic thyroid lobectomies, stage N1a, and larger tumor sizes. Post-lobectomy recurrences were significantly higher in the young age group. In the Cox analysis, young age, large tumor size, and stage N1a were significant risk factors. The multivariate analysis reveals that young age and stage N1a are significant risk factors. Conversely, minimally invasive or robot-endoscopic thyroidectomies were not risk factors for post-lobectomy recurrence compared to conventional thyroidectomies. While young patients with a stage N1a had a significant risk factor for post-lobectomy recurrence, endoscopic/robotic thyroidectomy was as feasible and safe as conventional thyroidectomies in the median seven-year oncologic follow-up. Further high-quality studies are needed to elucidate the relationship between age and the risk of post-lobectomy recurrence.

Prostate-specific membrane antigen expression predicts recurrence of papillary thyroid carcinoma after total thyroidectomy.

BACKGROUND: Prostate-specific membrane antigen (PSMA) overexpression has been observed in the endothelial neovasculature of several solid malignancies. This study aimed to identify PSMA expression in the primary tumor of classical papillary thyroid carcinoma (PTC) and assess the correlation between the degree of PSMA expression and recurrence. METHODS: We reviewed the electronic medical records of patients who underwent total thyroidectomy and central neck dissection, with or without lateral neck dissection, for classical PTC between 2009 and 2014 at our institution. Recurrence was defined as a structural disease based on histological confirmation on follow-up. Fifty-one patients with the recurrent structural disease were matched, using a propensity score matching method, to patients with no disease evidence during follow-up. Clinicopathological and follow-up data were collected for 102 patients. The monoclonal mouse anti-human PSMA/FOLH1/NAALADase I antibody was used for staining the primary tumor. The score of PSMA expression was classified as negative (< 5% positivity), weak (5-10 % positivity), moderate (11-49% positivity), and strong (more than 50% positivity). Clinicopathological factors were compared between patients with low and high PSMA expression. Moreover, whether the degree of PSMA expression and clinicopathological factors could predict recurrence was investigated. Cox proportional hazard regression models were used to evaluate the risk of recurrence. RESULTS: There was no significant difference in clinicopathological factors between low (negative or weak) and high (moderate or strong) PSMA expression. Gross extrathyroidal extension (ETE), absence of chronic lymphocytic thyroiditis, and high PSMA expression were all associated with lower recurrence-free survival (RFS) rate in a univariate analysis. In multivariate analysis, gross ETE (hazard ratio [HR], 2.279; 95% confidence interval [CI], 1.257-4.132; p = 0.007) and high PSMA expression (HR, 1.895; 95% CI, 1.073-3.348; p = 0.028) were associated with poor RFS. CONCLUSIONS: High PSMA expression in the primary tumor was a significant factor in predicting recurrence in classic PTC. PSMA could be a potential biomarker for personalized management for PTC.

Predictive Factors for Skip Lymph Node Metastasis and Their Implication on Recurrence in Papillary Thyroid Carcinoma.

Skip lymph node (LN) metastases in papillary thyroid carcinoma (PTC) belong to N1b classification in the absence of central neck LN involvement. This study aimed to evaluate the predictive factors of skip metastases and their impact on recurrence in PTC patients with pN1b. A total of 334 PTC patients who underwent total thyroidectomy with LN dissection (central and lateral neck compartment) followed by radioactive iodine ablation were included. Patients with skip metastases tended to have a small primary tumor (≤1 cm) and single lateral neck level involvement. Tumor size ≤ 1 cm was an important predictive factor for skip metastases. Univariate analysis for recurrence showed that patients with a central LN ratio > 0.68, lateral LN ratio > 0.21, and stimulated thyroglobulin (Tg) levels > 7.3 ng/mL had shorter RFS (recurrence-free survival). The stimulated Tg level was associated with shorter RFS on multivariate analysis (>7.3 vs. ≤7.3 ng/mL; hazard ratio, 4.226; 95% confidence interval, 2.226-8.022; p < 0.001). Although patients with skip metastases tended to have a small primary tumor and lower burden of lateral neck LN involvement, there was no association between skip metastases and RFS in PTC with pN1b. Stimulated Tg level was a strong predictor of recurrence.

Levothyroxine Cessation After Thyroid Lobectomy for Papillary Thyroid Cancer Can Be Achieved at the Same Rate as that for Benign Tumors Regardless of the Duration of Thyroid-stimulating Hormone Suppression.

BACKGROUND/AIM: Thyroid lobectomy may cause post-lobectomy hypothyroidism. We investigated the difference in levothyroxine (LT4) supplementation and cessation between patients with benign disease and those with papillary thyroid carcinoma (PTC) and found that the rate of LT4 cessation could be decreased after thyroid-stimulating hormone (TSH) suppression in PTC. PATIENTS AND METHODS: We retrospectively reviewed 88 patients with benign tumor and 463 patients with PTC and investigated the risk factors for LT4 supplementation after thyroid lobectomy. RESULTS: During the median follow-up of 73.0 months, 207 (37.6%) patients maintained the euthyroid state, while 344 (62.4%) patients continued LT4 supplementation for LT4 replacement or TSH suppression. In patients with benign tumors, only high pre-TSH level (>1.98 mIU/l) was a significant risk factor (odds ratio [OR]=10.09). However, in patients with PTC, pre-TSH level ≥1.98 mIU/l (OR=3.28), pregnancy planning (OR=2.97), and age ≥42.5 years (OR=1.94) were significant risk factors. Moreover, the most potent risk factor was tumor aggressiveness (OR=4.00), which was found to be more significant than high pre-TSH. The overall rate of LT4 cessation in all patients was 37.6%; however, in the 303 patients who underwent the LT4-Off trial, there was no difference in the rate in the benign tumor, low-risk PTC, and intermediate-risk PTC groups (66.2%, 68.8%, and 70.8%, respectively; p=0.886). CONCLUSION: When post-lobectomy TSH levels were adequate and the risk of recurrence was reduced, LT4 cessation in PTC could be achieved at the same rate as that in benign tumors, regardless of the duration of TSH suppression.