Effect of Radioactive Iodine Therapy on Cancer-Specific Survival of Papillary Thyroid Cancer Tall Cell Variant.

CONTEXT: Radioactive iodine (RAI) therapy is often used as an adjuvant treatment to reduce the risk of recurrence in patients with papillary thyroid cancer (PTC). However, the effect of RAI therapy on cancer-specific survival (CSS) in patients with tall cell variant (TCV) remains controversial. OBJECTIVE: This study aimed to investigate the impact of RAI therapy on CSS in patients with TCV-PTC by analyzing data from the Surveillance, Epidemiology, and End Results database. METHODS: We identified 1281 patients with TCV-PTC in the SEER database who underwent total thyroidectomy between 2004 and 2019. Of these, 866 (67.6%) patients received RAI therapy and 415 (32.4%) did not. Propensity score matching was conducted to balance the baseline characteristics between the 2 groups. Cox proportional hazards regression models were used to estimate the hazard ratio (HR) and 95% CI for the effect of RAI therapy on CSS. RESULTS: After propensity score matching, 373 pairs of patients were included in the analysis. The results showed no significant difference in CSS between the RAI therapy group and the non-RAI therapy group (HR 0.54, 95% CI 0.25-1.17, P = .120). Subgroup analyses indicated similar results. CONCLUSION: RAI therapy may not improve CSS in patients with TCV-PTC after total thyroidectomy. Future studies with larger sample sizes, longer follow-up periods, and better study designs are needed to confirm or refine our research findings.

A Prospective Study of Vitamin D Supplement in Thyroidectomy Patients Based on Relative Decline of Parathyroid Hormone.

Background: In postthyroidectomy patients, hypocalcemia is the most common complication to prolong hospital stay and decrease patients' satisfaction. Based on current evidence, it is recommended to supply vitamin D to patients with high risk of developing hypocalcemia. However, how to stratify the risk of patients remains challenging. Aim: We conducted a prospective study to evaluate the effect of vitamin D supplement (calcitriol) on high-risk hypocalcemia patients based on relative decline of parathyroid hormone (RDP). Method: RDP was calculated by the difference between preoperative and postoperative first-day PTH divided by preoperative PTH and presented as percentage. Patients who underwent total thyroidectomy in addition to bilateral central compartment dissection were enrolled prospectively and were divided into two cohorts: Cohort I: patients with RDP ≤70% and Cohort II: patients with RDP >70%. Patients in Cohort I were then randomly assigned to Group A or B, and patients in Cohort II were randomly assigned to Group C or D. All groups received oral calcium, and patients in Groups B and D also received calcitriol. All patients were followed for one year. In the study, standard procedure dictates that only oral calcium is given to patients whose RDP ≤70% and that oral calcium and calcitriol are given to patients whose RDP >70%. Therefore, Cohort I Group A and Cohort II Group D are controls in this study. Results: The incidence of clinical hypocalcemia in Groups A and D (the controls) was 11.0% (10/91), and 17.6% (16/91) required additional intravenous calcium. Of note, no patients developed permanent hypocalcemia. Furthermore, calcitriol supplement did not have significant impact on clinical outcomes between Group A and B in Cohort I. By contrast, calcitriol supplement distinctly improved clinical outcome by comparing Groups C and D (Cohort II), as marked by clinical hypocalcemia, need of requiring intravenous calcium, and long-termed decreased levels of PTH. Conclusion: Supplying calcitriol based on RDP cutoff of 70% may be a wise practice in thyroidectomy patients, and RDP 70% may be a useful predictor to stratify high-risk patients.

Ginsenoside Rg3 Inhibition of Thyroid Cancer Metastasis Is Associated with Alternation of Actin Skeleton.

Ginsenoside Rg3, a bioactive constituent from Panax ginseng, is a worldwide well-known traditional Chinese medicine used as a tonic. It also has good antitumor activity by inhibiting tumors metastasis. Tumor metastasis is a high risk in thyroid cancer. However, the effect and molecular mechanism underlying the antimetastatic activity of Rg3 in thyroid cancer have not been reported. In our study, we found that Rg3 inhibited the growth of thyroid cancer in vitro and in vivo and significantly inhibited metastasis of thyroid cancer. Rg3 apparently inhibited the migration and invasion in four papillary thyroid cancer (PTC) cells (TPC-1, BCPAP, C643, and Ocut-2c cells) and pulmonary metastasis in lung metastasis model of C643 cells in nude mice. We further found that a possible mechanism of Rg3 inhibiting thyroid cancer cells metastasis was associated with inhibiting cells actin skeleton function. Rg3 inhibited lamellipodia formation and induced microspike formation by inhibiting Rho GTPase in thyroid cancer cells. Rg3 decreased the levels of Rac-1 and Cdc42 proteins. In addition, Rg3 decreased the expression levels of matrix metalloproteinase-2 (MMP-2) and MMP-9 proteins in four thyroid cancer cells. The results that Rg3 remarkably inhibited the expression of vascular endothelial growth factor-C (VEGF-C) protein in PTC cells and VEGF-A protein in anaplastic thyroid cancer (ATC) cells and decreased the staining of CD31 in PTC and ATC tumors hinted that Rg3 might inhibit the lymph node metastasis in PTC and angiogenesis in ATC. These studies suggested that Rg3 might be a useful agent for the treatment of metastatic thyroid cancers.

Protocol for management after thyroidectomy: a retrospective study based on one-center experience.

BACKGROUND AND AIM: The optimal approach to detect and treat symptomatic hypocalcemia (SxH) after thyroidectomy is still uncertain. In our retrospective study, we sought to set a standardized postoperative management protocol on the basis of relative change of parathyroid hormone (PTH) and absolute value of postoperative day 1 (POD1) PTH. METHODS: Patients who underwent thyroidectomy were identified retrospectively in our prospective database. Blood was collected 1 day before surgery and on POD1. Extra calcium and calcitriol supplement was prescribed when necessary. Meanwhile, postoperative signs of SxH were treated and recorded in detail. Patients were followed up for 1 month after surgery and then 3 months thereafter. RESULTS: A total of 744 patients were included in the final analysis. Transient SxH occurred in 86 (11.6%) patients, and persistent SxH occurred in 4 (0.54%) patients in more than half year after surgery. Relative decrease of PTH reached its maximal discriminative effect at 70% (area under the curve [AUC] =0.754), with a sensitivity of 72.1% and a specificity of 75%. In Group 1 (≤70%), 24 (4.67%) patients were interpreted as having SxH, whereas in Group 2, 62 (27.0%) patients had SxH (>70%), P<0.001. Days of symptom relief in Group 1-1 (1, 2) were significantly shorter than those in Group 2-2 (1, 10), P=0.023. In Group 2, 112 (80%) patients with POD1 PTH <1 pmol/L were treated with calcitriol, whereas only 8 (8.89%) patients with POD1 PTH ≥1 pmol/L were treated with calcitriol (P<0.001). According to relief of SxH and recovery of parathyroid function, treating with and without calcitriol showed no difference in patients with POD1 PTH <1 and ≥1 pmol/L. CONCLUSION: Relative decrease of PTH >70% is a significant risk factor for SxH in post-thyroidectomy. The decreasing percent of PTH ≤70% ensures discharge on POD1, but longer hospitalization was advocated for patients with decreasing percent of PTH >70%, who needed extra calcitriol supplement when POD1 PTH <1 pmol/L.