Clinical Features of Early and Late Postoperative Hypothyroidism After Lobectomy.

Park, Suyeon; Jeon, Min Ji; Song, Eyun; Oh, Hye-Seon; Kim, Mijin; Kwon, Hyemi; Kim, Tae Yong; Hong, Suck Joon; Shong, Young Kee; Kim, Won Bae; Sung, Tae-Yon; Kim, Won Gu

<bold>Context: </bold>Lobectomy is preferred in thyroid cancer to decrease surgical complications and avoid lifelong thyroid-hormone replacement. However, postoperative hypothyroidism, requiring thyroid-hormone replacement, may occur.<bold>Objective: </bold>We aimed to identify the incidence and risk factors of postoperative hypothyroidism to develop a surveillance strategy after lobectomy for papillary thyroid microcarcinoma (PTMC).<bold>Methods: </bold>This historical cohort study involved 335 patients with PTMC treated by lobectomy. Postoperative thyroid functions were measured regularly, and patients were prescribed levothyroxine according to specific criteria. Patients not satisfying hormone-replacement criteria were closely followed up.<bold>Results: </bold>Postoperative hypothyroidism occurred in 215 patients (64.2%) including 5 (1.5%) with overt hypothyroidism and 210 (62.7%) with subclinical hypothyroidism. Forty patients (11.9%) were required thyroid hormone replacement. One hundred nineteen patients (33.5%) experienced temporary hypothyroidism and spontaneously recovered to euthyroid state. High preoperative thyroid-stimulating hormone (TSH) was the most important factor predicting postoperative hypothyroidism and failure of recover from hypothyroidism (odds ratio [OR], 2.82 and 1.77; 95% confidence interval [CI], 2.07 to 3.95 and 1.22 to 2.63; P < 0.001 and 0.002, respectively). Of the 215 patients eventually developing postoperative hypothyroidism, 70 (32.6%) developed hypothyroidism after the first postoperative year. Postoperative 1-year TSH levels were able to differentiate patients developing late hypothyroidism or euthyroidism (OR, 2.29; 95% CI, 1.68 to 3.26; P < 0.001).<bold>Conclusions: </bold>Preoperative and postoperative TSH levels might be predictive for patients who develop postlobectomy hypothyroidism and identify those requiring long-term surveillance for hypothyroidism. Additionally, mild postoperative hypothyroidism cases should be followed up without immediate levothyroxine replacement with the expectation of spontaneous recovery.

THYROXINE; AGE factors in disease; HYPOTHYROIDISM; LONGITUDINAL method; SURGICAL complications; THYROID gland tumors; THYROIDECTOMY; TIME; DISEASE incidence; PAPILLARY carcinoma; THERAPEUTICS

Journal of Clinical Endocrinology & Metabolism, 2017, pN.PAG

0021-972X

Academic Journal

10.1210/jc.2016-3597