Prediction of thyroid hormone supplementation after thyroid lobectomy.

Thyroid function, as assessed by thyroid-stimulating hormone (TSH) levels, was evaluated in patients after thyroid lobectomy. These assessments were analyzed against perioperative measurements to determine if any of these preoperative values were predictive of postoperative hypothyroidism and the need for postoperative levothyroxine treatment. In a retrospective study, data from 276 thyroid lobectomy patients were examined. These surgeries occurred over the period from January 2003-December 2012. Age, sex, volume of resected thyroid, thyroiditis, preoperative free T4, TSH, and microsomal antibody levels were analyzed for correlation with postoperative levothyroxine supplementation. The overall percentage of the patients taking postoperative levothyroxine was 23.6%. The preoperative TSH level showed strong correlation with TSH levels measured 1-mo postoperatively (P < 0.001). Preoperative TSH levels >2.5 mIU/L and positive microsomal antibody showed significant correlation with postoperative levothyroxine supplementation (P < 0.001; relative risk, 8.933, and 3.438, respectively). By stratifying the patients based on preoperative TSH levels and presence of microsomal antibodies, in the low-risk group with TSH <2.5 mIU/L and negative microsomal antibody, 7% of patients received postoperative levothyroxine replacement but in the high-risk group with TSH >2.5 mIU/L and positive microsomal antibody, 77.8% required levothyroxine replacement (P < 0.001). The most significant preoperative predictors for levothyroxine supplementation are preoperative TSH level and presence of microsomal antibodies. Patients with preoperative TSH <2.5 mIU/L showed a low risk of requiring postoperative levothyroxine supplementation.

Lee DY ，Seok J ，Jeong WJ ，Ahn SH ... -  《-》

Effects of endocrine therapy on the prognosis of elderly patients after surgery for papillary thyroid carcinoma.

Xia Q ，Dong S ，Bian PD ，Wang J ，Li CJ ... -  《-》

Factors associated with postoperative hypothyroidism after lobectomy in papillary thyroid microcarcinoma patients.

Park HK ，Kim DW ，Ha TK ，Choo HJ ，Park YM ，Jung SJ ，Kim DH ，Bae SK ... -  《-》

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.

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. We retrospectively reviewed 88 patients with benign tumor and 463 patients with PTC and investigated the risk factors for LT4 supplementation after thyroid lobectomy. 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). 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.

Na YM ，Cho JS ，Park MH 《-》

Thyroid Hormone Supplementation Therapy for Differentiated Thyroid Cancer After Lobectomy: 5 Years of Follow-Up.

Background: Lobectomy with preservation of the contralateral lobe has already become the most preferred surgical method for patients with low-risk thyroid cancer. The incidence of and risk factors for the development of hypothyroidism after lobectomy for thyroid cancer remains unclear. The previous practice of levothyroxine supplementation post-thyroidectomy, to bring about thyroid stimulating hormone (TSH) suppression, had some serious side effects. This study aimed to evaluate the incidence of hypothyroidism and to identify the factors associated with hypothyroidism requiring thyroid hormone replacement. Methods: We retrospectively reviewed the charts of 256 consecutive patients with differentiated thyroid cancer treated with lobectomy at the Gangnam Severance Hospital between April and December 2014 who were followed-up for more than 5 years. Patients were evaluated using a thyroid function test at the time of outpatient visit every 6 months for the 1st year, with an annual follow-up thereafter. Results: After 5 years, 66.0% (169) of the patients needed levothyroxine supplementation to maintain euthyroid status. The incidence of hypothyroidism requiring levothyroxine supplementation increased until 3 years but showed no significant change in the 4 and 5th year. Recurrence showed no difference between the group with and without levothyroxine supplementation. The presence of thyroiditis and preoperative TSH levels were correlated with postoperative levothyroxine supplementation to maintain euthyroid status, in univariate and multivariate analyses. Conclusion: High preoperative TSH levels and/or thyroiditis indicate a significantly increased likelihood of developing hypothyroidism requiring thyroid hormone supplementation after a thyroid lobectomy. Patients with an increased risk of postoperative hypothyroidism must be aware of their risk factors and should undergo more intensive follow-ups.

Kim SY ，Kim HJ ，Kim SM ，Chang H ，Lee YS ，Chang HS ，Park CS ... -  《Frontiers in Endocrinology》