PROSPECTIVE THERAPY STUDY IN DIFFERENTIAT ED THYROID-CANCER

Controversy still exists regarding the appropriate treatment for diffe rentiated thyroid carcinoma, i.e. the extent of surgery and the useful ness of prophylactic I-131 thyroid ablation. However, the debate is no wadays confined to those patients who may be categorized as having a f avorable prognosis with respect to tumor-related death or serious recu rrence, and the point of discussion is essentially the optimal treatme nt to prevent curable recurrences. From the literature it may be deduc ed that patients with a node negative papillary tumor of stage I and I I in the age-related TNM classification system, and patients with a mi nimally invasive follicular carcinoma, have an excellent prognosis wit h respect to survival and recurrence. In a prospective study during a 20-year period from one surgical and one pathological institution 136 consecutive patients were treated. Patients with an incidental pT(1) N -0 tumor, or with a stage I or II node negative papillary carcinoma, o r with a minimally invasive follicular carcinoma respectively, had a r educed extent of treatment. This consisted in resection for the concom itant benign goiter (7%), hemithyroidectomy (32%), or total thyroidect omy without I-131 ablation (18%). All other patients, including those with a node positive tumor in stage I or II, had total thyroidectomy a nd I-131 ablation (43%). Patients with a multifocal tumor had total th yroidectomy with or without I-131 ablation. Hemi- or total thyroidecto my was technically carried out by capsular dissection with identificat ion of the parathyroids, as introduced by Kocher and Halsted. Peritrac heal and -laryngeal nodes were regularly searched for, and functional neck dissection was done in node positive tumors. Total thyroidectomy was carried out by completion thyroidectomy in 29 (35%) of the 83 pati ents. 5 patients (7%) with papillary carcinoma, all in stage III or IV , and 5 patients (8%) with follicular carcinoma, all with a high degre e of capsular angioinvasion, died from the tumor 6 months to 16 years after diagnosis. A further patient with a high degree follicular carci noma is alive with residual disease. All these patients with an unfavo rable course underwent total thyroidectomy and I-131 ablation as initi al therapy. Two patients with papillary carcinoma had a presumptively curable recurrence, namely, a node recurrence in a pT(1) N-1 tumor (fo llowing total thyroidectomy and radioiodine ablation), and a contralat eral recurrence after hemithyroidectomy in a pT(2) No tumor in a young patient. In sum, in no case with an unfavorable course was a radical therapy omitted initially, and less than total thyroidectomy with I-13 1 ablation (n = 77 [57%]) led to a (curable) recurrence in only one in stance (1.3%). Permanent recurrent nerve palsy and permanent hypoparat hyroidism occurred in 1 (0.7%) and 3 patients (2.2%) respectively, all treated for follicular carcinoma with high degree of capsular angioin vasion. Conclusion: Patients at risk for an unfavorable course (death, serious recurrence) and for a (curable) recurrence can be defined and should be treated by total thyroidectomy and I-131 ablation. Patients without risk of continuous or recurrent disease can be properly selec ted for total thyroidectomy or hemithyroidectomy without radioiodine a blation.