Impact of the new guidelines of the American Thyroid Association on the treatment of the differentiated thyroid tumor in an Italian center with medium-high volume thyroid surgery.

BACKGROUND: The therapy for differentiated thyroid tumors is currently built upon two cornerstones: the stage of the disease and the new guidelines of the American Thyroid Association, jointly converging to lobohystmectomy for selected cases that meet certain criteria. The aim of the study was to relate these guidelines to the activity of an Italian center with a medium-high volume of thyroidectomies in a region with a high rate of endemic disease of the thyroid. METHODS: In order to conduct the analysis, the clinical records of the last 3 years, including 194 cases of total thyroidectomy and 3 lobohystmectomy, were taken into consideration. There were 46 cases of differentiated thyroid cancer (18 incidental tumors were found during thyroidectomies for benign diseases). Postoperative complications, patient characteristics and the stage of the tumor were assessed in relation to the new ATA guidelines. RESULTS: All patients underwent total thyroidectomy, with 2 of them also undergoing lymphadenectomy. The incidence of transient hypoparathyroidism was 19% with 1 case of permanent deficit. No cases of recurrent nerve injury were reported. Twenty-five out of the 28 patients with cancer preoperatively diagnosed were found with more nodules and in 15 of them the nodule had a diameter bigger than 1 cm. All the parameters suggested lobohystmectomy only for one case. The treatment for the differentiated thyroid tumor is still widely discussed. Above all, differences between populations, screening methods and surveillance programs are still evident. CONCLUSIONS: The ATA guidelines applied to our cases, even if limited, have shown limited applicability to our study, mainly due to the high incidence of multinodularity and the size of the nodule: typical characteristics of a region with a high rate of endemic thyroid pathology.

Poly(ADP-ribosyl)ation of proteins and germ cell development in hyperthyroid rat testes.

The effect of increased serum levels of thyroid hormone (triiodothyronine, T3) on young rat testis spermatogenesis was studied by analysing molecular and morphological parameters. Hyperthyroidism was induced by either T3-treatment or 2- and 10-day cold exposure. The poly(ADP-ribosyl)ation of proteins catalysed by poly(ADP-ribose) polymerase, which is particularly active at specific stages of rat spermatogenesis, was analysed as molecular index of DNA damage and cell stress. Poly(ADP-ribose) polymerase activity rose after both T3-treatment and 2- and 10-day cold exposure, with a trend of 10-day cold-exposed rats towards control values. In all hyperthyroid rats poly(ADP-ribose) turnover, as a contribution of both poly(ADP-ribose) polymerase and poly(ADP-ribose) glycohydrolase), was enhanced with respect to euthyroid animals. Poly(ADP-ribosyl)ation of proteins occurred with long and branched polymers suggesting an increased involvement of the modification system in DNA repair. Morphological changes of germ tissue were observed in hyperthyroid rats, mainly a high reduction of mature cells in the seminiferous tubule, and evidence of germ cell apoptosis was obtained by TUNEL method. In control animals germ cell apoptosis was within physiological levels. Conversely, in hyperthyroid rats a dramatic increase in the number of TUNEL-positive cells (some spermatogonia and numerous primary spermatocytes) was found, even though the increase was lower in 10-day than in 2-day cold-exposed animals.