Tall cell and diffuse sclerosing variants of papillary thyroid cancer: outcome and predicting value of risk stratification methods

PURPOSE

Tall cell (TCV) and diffuse sclerosing (DSV) variants are aggressive variants of papillary thyroid cancer (PTC). We compared the risk of recurrent/persistent disease in patients with TCV, DSV and classical PTC (cPTC) and evaluated the prognostic accuracy of initial vs. ongoing risk stratification.

METHODS

A consecutive series of DSV (n = 54), TCV (n = 72) and cPTC (n = 184) patients was retrospectively analyzed. TCV and DSV patients were first risk stratified for recurrent/persistent disease without considering the histotype as a risk factor and subsequently, 6-24 months after initial treatment, re-classified on the basis of the response to therapy (ongoing risk stratification).

RESULTS

Extrathyroidal extension was more frequent in DSV than in TCV and cPTC patients (p < 0.05); moreover, only DSV tumors had a higher rate of recurrent/persistent disease when compared to cPTC treated with the same protocol (total thyroidectomy followed by ¹³¹I treatment) (p < 0.01). After initial treatment, 54.2% of TCV and 20.4% of DSV patients were classified at low risk, while at ongoing risk stratification, the excellent response (low risk) was higher for both TCV (77.8%) and DSV (50.0%) patients relative to initial stratification (both p < 0.01). Using ongoing risk classification, positive predictive value (PPV) for persistent/recurrent disease was higher relative to initial risk stratification for both TCV (PPV = 93.8 vs. 39.4%) and DSV (PPV = 63.0 vs. 34.9%), p < 0.05 for both.

CONCLUSIONS

In our series DSV, but not TCV patients, had poorer outcome than cPTC treated with the same protocol. Moreover, the ongoing risk stratification predicted outcome better than the initial classification in both TCV and DSV patients.

Pregnancy outcome in women treated with methimazole or propylthiouracil during pregnancy

PURPOSE

Control of thyroid function in hyperthyroid women during pregnancy is based on antithyroid drugs (ATD) [propylthiouracil (PTU) and methimazole (MMI)]. While a teratogenic effect has been suggested for MMI and, more recently, for PTU, a clear demonstration is still lacking. Aim of this study was to assess the safety of ATD during pregnancy.

METHODS

A total of 379 pregnancies were retrospectively recruited in eight Italian Departments of Endocrinology and divided in five groups: (1) MMI-treated and euthyroid throughout pregnancy (n = 89); (2) MMI-treated and hyperthyroid on at least two occasions (n = 35); (3) PTU-treated women and euthyroid throughout pregnancy (n = 32); (4) PTU-treated women and hyperthyroid on at least two occasions (n = 20); and (5) non-ATD-treated (n = 203). Data on maternal thyroid function, miscarriages, type of delivery, neonatal weight, length and TSH, perinatal complications and congenital malformation were analyzed.

RESULTS

The gestational age at delivery, the rate of vaginal delivery, neonatal weight, length and neonatal TSH did not significantly differ among groups. In all groups, the rates of spontaneous miscarriage and of major congenital malformations were not higher than in the general population. No newborns were born with a phenotype similar to those described in the "MMI embryopathy".

CONCLUSIONS

While a clear demonstration of a teratogenic effect of MMI is currently lacking, it seems reasonable to follow the current guidelines and advice for PTU treatment in hyperthyroid women during the first trimester of pregnancy. Further, large and prospective worldwide studies will be needed to fully clarify the issue of ATD safety during pregnancy.

Human galectin-3 immunoexpression in thyroid follicular adenomas with cell atypia

Human galectin-3 (hgal-3) is a beta-galactoside binding protein involved in a number of physiological and pathological processes. Increasing hgal-3 immunoexpression has been reported in several human tumors, including thyroid carcinomas, but not in benign thyroid lesions. We analyzed the immunolocalization of hgal-3 in cell compartments of benign and malignant thyroid lesions. Hgal-3 immunoperoxidase reaction was carried out on 133 thyroid tissue samples obtained from 113 patients; 20 of these were normal (NT), 85 were benign thyroid lesions [20 colloid nodules (CN), 21 nodular hyperplasias (NH), 7 focal lymphocytic thyroiditis (FLT), 15 Hashimoto's thyroiditis (HT), 22 follicular adenomas (FA)], 25 differentiated carcinomas [15 papillary carcinomas (PC), 6 follicular carcinomas (FC) and 4 Hürthle cell carcinomas (HC)] and 3 anaplastic carcinomas (AC). Among the malignant thyroid lesions, hgal-3 was detected in 12/15 (80%) PC, 3/4 (75%) HC and in 4/6 (66.6%) FC, but in none of the 3 AC. Conversely, hgal-3 immunoexpression was absent in NT and in all benign thyroid lesions, but 1/15 HT and 10/22 (45.4%) FA. In the latter, hgal-3 was mostly expressed in microfollicular areas and in five of the six atypical FA. Hgal-3 cytoplasmic-perinuclear immunolocalization was observed in the majority of thyroid carcinomas and in more than half of the FA, theoretically suggesting an involvement of this protein in thyroid tumorigenesis throughout an antiapoptotic activity. Moreover, hgal-3 expression in FA might anticipate the likelihood of evolution of these benign lesions towards malignancy.

Attention deficit and hyperactivity disorders in the offspring of mothers exposed to mild-moderate iodine deficiency: a possible novel iodine deficiency disorder in developed countries

Over a period of almost 10 yr, we carried out a prospective study of the neuropsychological development of the offspring of 16 women from a moderately iodine-deficient area (area A) and of 11 control women from a marginally iodine-sufficient area (area B) whose thyroid function had been monitored during early gestation. Attention deficit and hyperactivity disorder (ADHD) was diagnosed in 11 of 16 area A children (68.7%) but in none from area B. Total intelligence quotient score was lower in area A than in area B children (92.1 +/- 7.8 vs. 110 +/- 10) and in ADHD children when compared with both non-ADHD children from the same area and control children (88.0 +/- 6.9 vs. 99.0 +/- 2.0 and 110 +/- 10, respectively). Seven of 11 ADHD children (63.6%) were born to the seven of eight area A mothers who became hypothyroxinemic at early gestation, whereas only one of five non-ADHD children was born to a woman who was hypothyroxinemic at 20 wk of gestation. So far, a similar prevalence of ADHD has been reported only in children with generalized resistance to thyroid hormones. This might suggest a common ADHD pathogenetic mechanism consisting either of reduced sensitivity of the nuclear receptors to thyroid hormone (generalized resistance to thyroid hormones) or reduced availability of intracellular T3 for nuclear receptor binding. The latter would be the ultimate consequence of maternal hypothyroxinemia (due to iodine deficiency), resulting in a critical reduction of the source of the intracellular T3 available to the developing fetal brain.

Post-Chernobyl increased prevalence of humoral thyroid autoimmunity in children and adolescents from a moderately iodine-deficient area in Russia

Circulating thyroglobulin antibodies (TgAb) and thyroperoxidase antibodies (TPOAb) were measured in 143 iodine-deficient children, 5 to 15 years of age, from the Region of Tula, Russia, who had been moderately contaminated after the Chernobyl disaster (37-185 GBq/km2 of caesium-137, [group A]) and in 40 sex- and age-matched subjects from an uncontaminated neighboring area (<3.7 GBq/km2 of caesium-137, [group B]). Increased thyroid size at sonography was found in 41% and in 45% subjects from group A and group B, respectively, associated with supranormal thyrotropin (TSH) values in 7.7% of group A and 7.5% of group B, without differences in average serum free thyroxine (FT4), free triiodothyronine (FT3) and TSH. Serum thyroperoxidase antibody (TPOAb)-associated or not with thyroglobulin-antibody (TgAb) as detected in 18.9% of children and adolescents from group A, about four-fold higher than in group B (5%, Fischer's exact test p<0.05). A 24% frequency was found in subjects whose age, at the moment of the disaster was 0-72 months or were in utero, but the frequency was about 7%, similar to that in group B, in those who had not yet been conceived at that time. Less than half of antibody-positive group A children were hyperthyrotropinemic, whereas no group B subclinical hypothyroid subject was antibody-positive, thus excluding the autoimmune etiology of the subclinical thyroid failure; more likely it is attributable to iodine malnutrition. The high prevalence of humoral thyroid autoimmunity phenomena in the investigated area suggests a combined role of iodine malnutrition in enhancing the effects of short lived iodine isotopes, particularly evident in pubertal individuals conceived or born immediately before the Chernobyl disaster.

Short-term effectiveness of low-dose radioiodune ablative treatment of thyroid remnants after thyroidectomy for differentiated thyroid cancer

Twenty-five patients from a marginally iodine-deficient area with differentiated thyroid cancer who were referred to our unit between 1991 and 1997 had a residual thyroid uptake (RTU) at 24 hours of 5% or more after surgery. None of them underwent reoperation: 8 of 25 had RTU between 5% and 10% and were considered at low risk for both local recurrences and/or distant metastases; 17 of 25 had RTU greater than 10% and up to 30% and refused re-intervention. After detection of their cervical uptake by using a 131I tracer dose of 3.7 MBq (100 microCi), all 25 were treated with 1110 MBq (30 mCi) of 131I. A whole-body scan (WBS) performed 5 days later revealed 131I uptake corresponding to metastatic lymph nodes in the anterior part of the neck in 1 patient and the persistence of only RTU in 24 of 25 patients. RTU and thyroglobulin (Tg) levels were reevaluated 6 months later in all patients and compared to preradioiodine treatment values. RTU, ranging at presentation between 5% and 30%, decreased to below 1% in all but one patient. Serum Tg values, ranging between 1.6 and 108 ng/mL before radioiodine treatment, decreased to below 1.6 ng/mL in all but 4 of them (whose serum Tg was between 2 and 3.4 ng/mL). Our data indicate that 1,110 MBq of 131I can permit complete ablation of 80% of thyroid remnants concentrating up to 30% of radioiodine activity. A relation between this high success rate and iodine deficiency can be hypothesized because an increasing uptake of radioiodine by thyroid remnants could result in overestimation of their size. Therefore, our observations suggest that in iodine deficient areas, a hasty decision to carry out complete thyroidectomy should be avoided, even in the case of thyroid remnants with RTU up to 30%.

Increased risk of maternal thyroid failure with pregnancy progression in an iodine deficient area with major iodine deficiency disorders

In an effort to assess the impact of moderate iodine deficiency on maternal thyroid function during pregnancy, we measured serum thyrotropin, total and free thyroid hormones, thyroid-binding globulin (TGB) at 8, 14, 20, 29, and 36 weeks of gestation, along with urinary iodide excretion, in 10 healthy women from a moderately iodine deficient region (group A), and compared them with 6 women from an iodine sufficient region (group B). Serum total thyroxine (T4) fell significantly in group A, and was significantly lower than in group B at 29 and 36 weeks (p<0.05). TBG saturation was significantly lower in group A throughout pregnancy, and declined in both groups as pregnancy progressed. Free thyroxine (T4) and triiodothyronine (T3) concentrations fell in both groups, and FT4 values were significantly lower in group A than group B in the third trimester (p<0.05). Urinary iodine excretion was lower in group A women with respect to group B and did not vary significantly in either group as gestation progressed. The serum T3/T4 molar ratio increased through pregnancy only in group B. Thyrotropin concentrations rose in both groups through pregnancy, and were higher in group A at term (p< 0.01). The incidence of isolated hypothyroxinemia or biochemical hypothyroidism doubled (30% to 70%) between midgestation and term in group A, suggesting that moderate iodine deficiency may result in maternal thyroid failure during the later stages of pregnancy.