Background: Active surveillance (AS) is an alternative to thyroidectomy for the management of low-risk papillary thyroid microcarcinoma (PTMC). However, prospective AS data collected from diverse populations are needed. Methods: This multicenter prospective cohort study enrolled patients from three referral hospitals in Korea. The participants were self-assigned into two groups, AS or immediate surgery. All patients underwent neck ultrasound every 6–12 months to monitor for disease progression. Progression under AS was evaluated by a criterion of tumor size increment by 3 mm in one dimension (3 mm), 2 mm in two dimensions (2 × 2 mm), new extrathyroidal extension (ETE), or new lymph node metastasis (LNM), and a composite outcome was defined using all four criteria. Results: A total of 1177 eligible patients with PTMC (919 female, 78.1%) with a median age of 48 years (range 19–87) were enrolled; 755 (64.1%) patients chose AS and 422 (35.9%) underwent surgery. Among 755 patients under AS, 706 (female 537, 76.1%) underwent at least two ultrasound examinations and were analyzed. Over a follow-up period of 41.4 months (standard deviation, 16.0), 163 AS patients (23.1%) underwent surgery. Progression defined by the composite outcome was observed in 9.6% (68/706) of patients, and the 2- and 5-year progression estimates were 5.3% and 14.2%, respectively. The observed progression rates were 5.8% (41/706) and 5.4% (38/706) as defined by tumor size enlargement by 3 mm and 2 × 2 mm, respectively, and 1.3% (9/706) and 0.4% (3/706) for new LNM and ETE, respectively. No distant metastases developed during AS. In multivariate logistic regression analysis examining variables associated with progression under AS, age at diagnosis <30 years (odds ratio [OR], 2.86; 95% confidence interval [CI], 1.10 − 7.45), male sex (OR, 2.48; 95% CI, 1.47 − 4.20), and tumor size ≥6 mm (OR, 1.89; 95% CI, 1.09 − 3.27) were independently significant. Conclusions: The progression of low-risk PTMC during AS in the Korean population was low, but slightly higher than previously reported in other populations. Risk factors for disease progression under AS include younger age, male sex, and larger tumor size. Clinical trial registration: Clinicaltrials.gov NCT02938702.

Moon JH, et al. Endocrinol Metab. 2018 Jun;33(2):278-286. https://doi.org/10.3803/EnM.2018.33.2.278

Background: Transoral endoscopic thyroidectomy vestibular approach (TOETVA) is a scarless alternative to open thyroidectomy (OT). This systematic review and meta-analysis aimed to synthesize evidence comparing the intraoperative and postoperative outcomes of TOETVA and OT. Methods: A systematic literature search of PubMed, Web of Science, the Cochrane Library, and Google Scholar was performed to identify studies comparing the outcomes of TOETVA and OT published before February 2023. The outcomes of interest were operative time, intraoperative blood loss, hospital stay, postoperative pain, number of central lymph nodes retrieved, number of metastatic central lymph nodes, and incidences of transient and permanent recurrent laryngeal nerve injury, transient and permanent hypocalcemia, hematoma, and infection. Results: Thirteen studies published between 2016 and 2022, involving a total of 2889 patients (TOETVA, n=1085; OT, n=1804) were included in this systematic review and meta-analysis. Meta-analysis showed that the TOETVA group had a significantly longer overall operative time (weighted mean difference [WMD] 55.19; 95% CI, 39.15, 71.23; P<0.001), longer hospital stay (WMD, 0.27; 95% CI, 0.14, 0.39; P<0.001), and lower pain scores on postoperative day 1 (WMD, −1.41; 95% CI, −2.79, −0.03; P=0.04) than the OT group. Other intraoperative and postoperative outcomes were not significantly different between the groups. Conclusion: TOETVA has a similar safety profile to OT with less postoperative pain, making it an appropriate and more cosmetically appealing alternative to OT for select patients.

Cigarette smoking is believed to affect thyroid function and autoimmune thyroid disease. However, there is little information to analyze their association using objective biomarkers. The aim of this study was to investigate the dose-related effect of smoking on thyroid hormones and thyroid peroxidase antibody (TPO Ab) using urinary cotinine levels and a population-based cohort. The present study used the thyroid hormone and urinary cotinine dataset from sixth Korean National Health and Nutrition Examination Survey in 2014 and 2015, and a total of 4249 participants were included. Dose-response relationships between thyroid hormone (free T4, TSH, and TPO Ab) and urinary cotinine levels were estimated using ANCOVA after adjustment for all variables (age, height, weight, alcohol, exercise, and log- transformed iodine in urine). Urinary cotinine level was negatively correlated with TSH. The estimated coefficients were −0.0711 in males and −0.0941 in females (p < 0.0001). TPO Ab titer was positively correlated with cotinine levels in males (p < 0.0001). Our findings indicated a significant dose-related effect of urinary cotinine level on thyroid function, and thyroid autoimmunity.