Thyroid cancer prevalence after radioiodine treatment of hyperthyroidism.

UNLABELLED: The definitive treatment of hyperthyroidism in Europe is quite different from that in the United States. In Europe, the surgical approach is often preferred and considered safer than radioiodine treatment. European doctors usually prefer to surgically remove the thyroid and perform a pathologic examination of it. They consider it to be an essential diagnostic tool to identify possible diseases that might be associated with hyperthyroidism and even to detect the rare thyroid tumors that might be associated with thyroid hyperfunction. The aim of this study was to evaluate whether radioiodine therapy could be a risk factor for the misdiagnosis of thyroid cancer. METHODS: We performed a retrospective revision of data we collected from 6647 patients (1171 [17.5%] men, 5476 [82.5%] women), all of whom underwent 1311 therapy for hyperthyroidism from 1970 to 1997. Of the whole group, 6.5% were younger than 40 y, 33.5% were 40-60 y old, and 60% were older than 60 y. Moreover, 5061 (76%) patients had either an autonomously functioning node or a toxic multinodular goiter. The other 1586 (24%) patients had Graves' disease. RESULTS: After treatment, thyroid cancer was discovered in 10 (0.15%) patients, none of whom belonged to the group of patients with Graves' disease. Five of these patients were treated during a period from 1970 to 1980, when sonography was not routinely available. The incidence of thyroid cancer in the series of radioiodine-treated patients (150/100,000 over a 27-y period) was not significantly different from its incidence in the general population. The expected rate is 124.88 per 100,000 over a 27-y period. CONCLUSION: An accurate preliminary evaluation (clinical examination, sonography, and cytologic evaluation of fine-needle aspiration) is fundamental for a proper choice between radioiodine and surgical therapy.

Circadian profile of serum melatonin in patients with Cushing's syndrome or acromegaly.

We evaluated the 24-h profile of serum melatonin (MT) in 16 patients with Cushing's syndrome (11 pituitary- and 5 adrenal-dependent) aged 38.1 +/- 13.8 years and in 19 patients with acromegaly due to GH-secreting pituitary adenoma aged 52 +/- 11.9 years. Thirty-three healthy subjects aged 30 +/- 7 years and 26 healthy subjects aged 59 +/- 12 years served as age-matched controls for the two groups of patients, respectively. All the patients had active disease and were off treatment; none had overt hypopituitarism. Blood drawings were collected at 08:00, 12:00, 16:00, 20:00, 22:00, 24:00, 02:00, 04:00 and 06:00 h in controls and patients. Serum MT, cortisol, GH and IGF-I were measured by specific RIA kits and ACTH by IRMA. Cosinor rhythmometry was employed for chronobiological analysis. The acromegalic patients displayed, as a whole group, higher 24-h mean MT levels with respect to age-matched controls (M +/- SD: 52.9 +/- 14.6 vs 32.9 +/- 8.0 pg/ml, p < 0.01) with normally synchronized MT profiles in 11/19 patients. No correlation was apparent between MT and either GH (24-h mean) or IGF-I. In the patients with Cushing's syndrome the circadian profile of serum MT was maintained in 10/16 cases; serum MT levels were comparable to those of controls (48.8 +/- 14.0 vs 50.0 +/- 16.0 pg/ml, NS) without any difference between pituitary- and adrenal-dependent forms. No correlation was found between MT and either ACTH or cortisol levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Biochemical markers of bone and collagen turnover in acromegaly or Cushing's syndrome.

We evaluated serum bone Gla-protein (osteocalcin, BGP), carboxyterminal propeptide of type I procollagen (PICP) and aminoterminal propeptide of type III procollagen (PIIINP) in 15 patients with active acromegaly (6M aged 27-54, 4 PMF aged 39-51, 5MP aged 54-65 years), 12 with active Cushing's syndrome [(CS) 2M of 32 and 42 years; 4PMF aged 25-40; 6MF aged 50-64)] and controls evenly matched for age, sex and menstrual status. Patients with acromegaly were evaluated before and at regular intervals on octreotide treatment (50-150 micrograms t.i.d., s.c.); the duration of the follow-up was 5-49 months (median 28). Endocrine evaluation included measurements of serum GH, IGF-I, BGP, PICP and PIINP. In a case-control analysis, acromegalic patients showed increased BGP (14.3 +/- 2.1 vs 8.3 +/- 2.1 ng/ml p < 0.001) and PIIINP concentrations (4.8 +/- 1.4 vs 3.1 +/- 0.7 micrograms/l, p < 0.02). During octreotide treatment we observed a roughly parallel decline of GH, IGF-I and BGP. BGP and log-transformed 24-h mean GH concentrations were positively correlated (r = 0.48, p < 0.001) as was the case for BGP and IGF-I (r = 0.43, p < 0.001). Also PIIINP correlated with log-transformed GH (r = 0.58, p < 0.001) and IGF-I (r = 0.35, p < 0.05). Serum PICP did not differ in the two groups (152 +/- 55 vs 120 +/- 55 micrograms/l, NS) and did not correlate either with GH or IGF-I. Patients with CS were evaluated measuring serum and urinary cortisol (UFC), ACTH, BGP, PICP, PIIINP.(ABSTRACT TRUNCATED AT 250 WORDS)