Selective Treatment of Differentiated Thyroid Carcinoma

Abstract. Over a period of 20 years 84 papillary and 82 follicular carcinomas operated on by one surgeon and examined by one pathologist were documented prospectively, treated selectively, and followed for 1 to 20 years (median 7 years). Tumors with a low risk of recurrence or incurable disease—i.e., papillary carcinoma pT1–3 N0 M0 (

n = 56) and minimally invasive follicular carcinoma ( n = 37)—were treated by a limited-radicality hemithyroidectomy or total thyroidectomy without radioiodine in 79 of the 93 cases (85%). No unfavorable course was observed, and only one curable recurrence (1.3%) developed contralaterally after hemithyroidectomy for papillary cancer. Of the remaining 73 patients, including 100% of those with nodal involvement, 65 (89%) underwent total thyroidectomy with radioiodine. Total thyroidectomy was achieved in 34% of the cases by completion thyroidectomy, based on definitive histologic examination. No instance of a serious, potentially incurable recurrence and no tumor-related death was observed in patients with a papillary TNM stage I + II or with a minimally invasive follicular carcinoma. Five of the patients (6%) with papillary carcinoma, all with TNM stage III or IV, and seven of the patients (8.5%) with follicular carcinoma, all grossly invasive and pT3 or pT4, had tumor-related deaths following total thyroidectomy in all and with remnant ablation in 10 cases. A potentially curable node recurrence occurred in two patients 1 and 10 years, respectively, after primary treatment. Permanent hypoparathyroidism ( n = 4) (2.4%) and permanent recurrent laryngeal nerve palsy ( n = 2) (1.2%) were observed only in patients with a grossly invasive follicular carcinoma and concomitant benign recurrent goiter. We conclude that (1) hemithyroidectomy or total thyroidectomy without radioiodine is adequate for papillary carcinoma pT1–3 N0 and minimally invasive follicular carcinoma; (2) there were no nodal recurrences in tumors recognized as node-negative; and (3) extracapsular excision of one or both lobes can be carried out technically with low morbidity. The study confirms the prognostic value of age-related TNM classification for papillary carcinoma; classification of follicular thyroid carcinoma as minimally invasive or grossly invasive proved to be useful.