Effectiveness of the iodine prophylaxis model adopted in Poland.

OBJECTIVE: Most of the Polish territory has been classified as an iodine-deficient and endemic goiter area according to the International Council for Control of Iodine Deficiency (ICCIDD) criteria. In 1997 the obligatory model of iodine prophylaxis was implemented. Our investigations were aimed at the effectiveness of iodine prophylaxis in Poland. METHODS: We assessed urinary iodine excretion and goiter prevalence in 5663 children aged 6-12 yr. The population of children from the same 27 schools was investigated from 1992 to 1994 (1406 girls and 1244 boys) and from 1999 to 2005 (1563 girls and 1450 boys) using identical laboratory and ultrasound methods. RESULTS: We found significant increase in iodine urinary concentration (median 52 microg/l vs 93 microg/l, p<0.001) with accompanying drop in goiter prevalence (29.6% vs 5.2%, p<0.001) after implementation of iodine prophylaxis. Iodine excretion distribution changed significantly after 1997 with an increase in the percentage of children with iodine urinary concentration above 100 microg/l from 10.8% to 45.4%, respectively. A significantly higher iodine urinary concentration was observed in lowlands compared to uplands both before and after implementation of iodine prophylaxis (median, 50 microg/l vs 57 microg/l and 86 microg/l vs 114 microg/l, respectively, p<0.001). The goiter prevalence did not differ between girls and boys from 1992 to 1994 (28.8% vs 30.5%, p=0.35) and 1999 to 2005 (5.5% vs 4.9%, p=0.45). CONCLUSIONS: Implementation of the new model of iodine prophylaxis in Poland in 1997 has led to significant increase in iodine urinary concentration and decrease in goiter prevalence among Polish schoolchildren. In the youngest group of children (6-8 yr olds), prevalence of goiter decreased to 3.2%--i.e. below endemic levels.

A programme of iodine supplementation using only iodised household salt is efficient--the case of Poland.

BACKGROUND: Iodine prophylaxis in Poland started in 1935 and has been interrupted twice: by World War II and in 1980 for economic reasons. Epidemiological surveys carried out after the Chernobyl accident in 1989 as well as in 1992/1993 and in 1994 as a 'ThyroMobil' study, revealed increased prevalence of goitre in children and adults. Ninety per cent of Poland was classified as an area of moderate iodine deficiency, and 10%, in the seaside area, as mild iodine deficiency territory. Iodine prophylaxis based on iodisation of household salt was introduced again in 1986 as a voluntary model and in 1997 as a mandatory model with 30+/-10 mg KI/kg salt. OBJECTIVE: The evaluation of the obligatory model of iodine prophylaxis in schoolchildren from the same schools in 1994 and 1999. METHODS: Thyroid volume was determined by ultrasonography. Ioduria in casual morning urine samples was measured using Sandell-Kolthoff's method, within the framework of the ThyroMobil study. RESULTS: Goitre prevalence decreased from 38.4 to 7% and urinary iodine concentration increased from 60.4 to 96.2 microg/l mean values between 1994 and 1999. In four schools the prevalence of goitre diminished below 5%. In 1999, 70% of children excreted over 60 microg I/l, and 36% over 100 microg I/l, whereas in 1994 the values were 44 and 13% respectively. CONCLUSION: The present findings indicate that iodine prophylaxis based only on iodised household salt is highly effective.

[Biological risk factors for differentiated thyroid cancer]. / Biologiczne czynniki ryzyka zróznicowanego raka tarczycy.

UNLABELLED: Apart from the two relatively well documented risk factors for thyroid cancer i.e. iodine deficiency and ionising radiation, the mechanism of carcinogenesis involves a number of biological and environmental factors. The aim of the study was to analyse the selected biological and environmental risk factors in patients with differentiated thyroid cancer in comparison with a reference group in a case-control study. METHODS: Both the group of 188 women and 30 men with thyroid cancer including 92 with follicular carcinoma and 126 with papillary carcinoma and the control group of 287 women and 58 men were subjected to the examination. All the study participants were given a standard questionnaire and underwent physical examination including thyroid USG, blood hormone levels and urine iodine concentration. The following risk factors were included in the analysis: family history, sex, age, thyroid morbidity, employment, body weight, hormone replacement therapy in women, cigarette smoking. In both groups with thyroid cancer women predominant with the female to male ratio 6.7 in follicular carcinoma and 6.0 in the papillary variant. In both groups of diagnoses the mean age was high--above 50, higher in men than in women. Over 70% of the patients with thyroid cancer had nodular goitre before the detection of cancer. In the control group the proportion of diagnosed goitre was slightly above 10%. A significantly more frequent hormone replacement therapy and contraception and more frequent miscarriages in women with thyroid cancer were noteworthy. One may assume that initiation, promotion and progression of the neoplastic process in the thyroid is triggered by a number of factors, both biological and environmental, and only multifactorial analysis may provide an insight into the mechanisms of carcinogenesis followed by initiation of preventives measures in appropriate cases.

[Ionizing radiation as a risk factor for thyroid cancer in Krakow and Nowy Sacz regions]. / Promieniowanie jonizujace jako czynnik ryzyka raka tarczycy w obszarze Krakowa i Nowego Sacza.

In a group of 224 patients with thyroid cancer registered from 1990 to 1999 and in 243 controls matched for sex and age doses for the thyroid due to accumulation of 131I after Chernobyl accident and radiological diagnostic procedures involving the neck and dentition was calculated according to Johnson's model and based upon questionnaires. There was a significantly higher dose for the thyroid due to accumulation of 131I in the Krakow area in comparison with the Nowy Sacz area. There was also a significantly higher frequency of radiological procedures involving the thyroid gland preceding the development of thyroid cancer in comparison with the control group. The present findings are concordant with about 40% increase of thyroid cancer in the Krakow area in comparison with the Nowy Sacz region. The present study has indicated that ionising radiation may be a factor involved in the pathogenesis of thyroid cancer and its significant rise within the last 10 years. However, it has not been the main factor, but only one of the risk factors. The study has also indicated that iodine prophylaxis should be continued and that radiological procedures involving the neck and head in patients with nodular goitre should be carried out with caution.

[Epidemiology of thyroid cancer in Poland]. / Epidemiologia raka tarczycy w Polsce.

The aim of the paper is to analyse the epidemiological situation of thyroid cancer in Cracow region from 1986 to 1999 and to review regional thyroid cancer registers in Poland (including 43.7% of the Polish population) in 1999. The standardized register was based upon assumptions: 100% of histopathological verification according to ICD-10, the register ascertainment in at least 80%, the demographic area not smaller than 100,000 inhabitants, the incidence rate (IR) calculated as the newly diagnosed cases number per 100,000 inhabitants in a calendar year. Since 1990 a statistically significant rise of the thyroid cancer incidence affecting mainly women > 40 years of age have been observed. From 1998-1999 the cancer morbidity was reduced. Within the last 5 years in the Cracow area the follicular carcinoma incidence has decreased significantly, which has been associated with effective iodine prophylaxis. The highest incidence values have been observed in Cracow and Olsztyn, showing a territorial relationship with the highest thyroid irradiation doses after Chernobyl accident. The mean IR value has been 3.86 (1.48 men, 6.08 women), which corresponds to about 1500 newly diagnosed cases in Poland in 1999. The follicular to papillary carcinoma ratio has been 5.32. The major etiological factors have been iodine deficiency and ionising radiation. The present data have indicated that iodine prophylaxis should be continued and that the population should be protected against ionising radiation.

[Iodine deficiency and thyroid neoplasms in the Krakow region]. / Niedobór jodu a rak tarczycy w regionie krakowskim.

The aim of the study was to evaluate the correlation between incidence rate (IR) of thyroid cancer and severity of iodine deficiency. The influence of iodine prophylaxis on IR was also investigated. The suspension of iodine prophylaxis in 1980 resulted in goitre prevalence increase in schoolchildren (up to 60%) and elevated TSH levels in neonates observed in early 1990-ties. In 1990 rise in thyroid cancer IR was observed. IR of papillary and follicular carcinoma in 1995 were 1.6 and 1.5 respectively. Papillary to follicular ratio was about 1.0. Such a high prevalence of follicular cancer was specific for iodine deficient regions. In 1997, after introduction of mandatory model of iodine prophylaxis in Poland, increase in papillary thyroid cancer IR was observed, reaching in 1998 6.23 per 100,000 inhabitants. Papillary to follicular cancer ratio rose to 2.48. In 1999 no further increase in thyroid cancer IR was observed. Increase in papillary cancer incidence between 1990 and 1999 may be related to overlapping of iodine deficiency and other cancer risk factors i.e. radiation after Chernobyl accident.

[Expression of protein p53: the marker of low neoplastic cell differentiation in thyroid carcinoma]. / Ekspresja bialka p53: marker niskiego zróznicowania komórek nowotworowych w raku tarczycy.

UNLABELLED: The aim of the study was to evaluate the frequency of positive staining of p53 protein in the course of thyroid carcinoma and to establish the prognostic value of such expression. MATERIAL AND METHOD: Immunohistochemical staining of frozen sections was performed in 159 patients with thyroid carcinoma (139 females and 29 males). The average age was 50.4 years. All patients have been followed-up for at least 5 years and the average time of observation was 10.7 years. There were 46% patients with papillary carcinoma, 39% with follicular carcinoma and 15% with poorly differentiated thyroid carcinoma in the study group. Additionally, staining was performed in 6 cases of anaplastic carcinoma. The expression of p53 protein was assessed by two-degree scale: a medium (10% of cells with positive staining) and strong (50% of positive staining). RESULTS: In the group of 135 patients with well differentiated thyroid carcinoma the expression of p53 protein has been found in 55 cases (40.1%) but significantly more often in medium (69.1%) than in strong degree (30.9%). Significantly more often in expression has occurred among patients with poorly differentiated carcinoma (66%) and anaplastic carcinoma (100% of patients with strong expression in all cases). Comparing the frequency of p53 protein expression on every stage of disease, no significant difference has been found. The presence of p53 protein has not correlated with reduced changes in survival. In multivariate analyses the expression of p53 protein have not shown prognostic value. CONCLUSION: The expression of p53 protein has concerned the poorly differentiated carcinomas of thyroid and has not correlated with the stage of disease. No influence of expression on clinical course of the well differentiated thyroid carcinoma has been found. Worse prognoses have correlated with poor differentiated thyroid cancer cases and with strong expression of p53 protein.

Goiter incidence and urinary iodine excretion in children of age group 6-13 years living in south-eastern Poland (Kraków coordinating center).

The study included 4103 school children attending randomly selected schools localized in towns and villages of 3 geographically distinct regions: mountainous, (Carpathian endemia), upland, lowland. The children were divided into four age-related groups. The incidence of goiter as detected by palpation was 38.1% in all the children studied, the value being similar in all three regions (38.1, 37.3 and 38.6%, respectively). Goiter incidence differs slightly among urban and rural children, amounting to 40.5 and 34.5%, respectively, in the two groups. In about 60% of children urinary iodine excretion was lower than 50 micrograms/l, while in about 30% it was normal. In about 10% of children studied urinary iodine excretion was lower than 20 micrograms/l. The results obtained indicate the occurrence among children of the studied region of goiter endemy of moderate degree. It was found that the percentage of children excreting more than 50 micrograms/l of urinary iodine was higher among those consuming iodized salt as compared to those consuming non-iodized salt. The first effects of resumption of common salt fortification with iodide in southern Poland can already be noted. There is, however, a need for optimization and steady control over this prophylactic action.

Glucagon-Like Peptide-1 Receptor Imaging with [Lys (40) (Ahx-HYNIC- (99 m) Tc/EDDA)NH 2 ]-Exendin-4 for the Diagnosis of Recurrence or Dissemination of Medullary Thyroid Cancer: A Preliminary Report.

Introduction. Epidemiological studies on medullary thyroid cancer (MTC) have shown that neither a change in stage at diagnosis nor improvement in survival has occurred during the past 30 years. In patients with detectable serum calcitonin and no clinically apparent disease, a careful search for local recurrence, and nodal or distant metastases, should be performed. Conventional imaging modalities will not show any disease until basal serum calcitonin is at least 150 pg/mL. The objective of the study was to present the first experience with labelled glucagon-like peptide-1 (GLP-1) analogue [Lys(40)(Ahx-HYNIC-(99m)Tc/EDDA)NH2]-exendin-4 in the visualisation of MTC in humans. Material and Method. Four patients aged 22-74 years (two with sporadic and two with MEN2 syndrome-related disseminated MTC) were enrolled in the study. In all patients, GLP-1 receptor imaging was performed. Results. High-quality images were obtained in all patients. All previously known MTC lesions have been confirmed in GLP-1 scintigraphy. Moreover, one additional liver lesion was detected in sporadic MTC male patient. Conclusions. GLP-1 receptor imaging with [Lys(40)(Ahx-HYNIC-(99m)Tc/EDDA)NH2]-exendin-4 is able to detect MTC lesions. GLP-1 scintigraphy can serve as a confirmatory test in MTC patients, in whom other imaging procedures are inconsistent.

Influence of iodine deficiency and iodine prophylaxis on thyroid cancer histotypes and incidence in endemic goiter area.

The aim of the study was to evaluate the correlation between thyroid cancer histotype and incidence rate (IR) and iodine nutrition level in two endemic goiter areas: the districts of Krakow and Nowy Sacz. The suspension of iodine prophylaxis in Poland in 1980 resulted in increased goiter prevalence in schoolchildren and adults and elevated TSH levels in newborns in the early 1990s. Since 1992 a rise in thyroid cancer IR was observed. Thyroid cancer IR in the Krakow population was 2.22 in 1986; 3.62 in 1995 and 6.02 in 2001; in Nowy Sacz: 1.52; 2.59 and 3.88 respectively. In 1986 papillary/follicular cancer ratio in both areas was about 1.0--the value typical of iodine deficient areas. After restoring the obligatory iodine prophylaxis in 1997, a significant decrease in elevated TSH concentration in newborns and urinary iodine concentration increase in schoolchildren were observed. A relative rise in the incidence of papillary thyroid cancer and decrease in follicular cancer, resulting in rise in papillary/follicular thyroid cancer ratio up to 5.9 in 2001 was also observed. Since 1999 no further thyroid cancer IR increase was noted. In conclusion, a significant increase in differentiated thyroid cancer IR was observed in association with the iodine prophylaxis suspension. Changes in thyroid cancer histotypes in 1986-2001 and a significant decrease in incremental rate of differentiated thyroid cancer probably reflect the influence of effective iodine prophylaxis. The significant difference between IR of thyroid cancer incidence in the districts of Krakow and Nowy Sacz may be related to differences in the exposure to radiation after the Chernobyl accident.

Incidence of thyroid cancer in the selected areas of iodine deficiency in Poland.

The aim of the study was to evaluate the incidence rate (IR), trend and histotype of the differentiated thyroid cancer in the selected areas with varying iodine deficiency. The study was carried out in three areas: Krakow, (Carpathian endemic goiter area with 1.99 million mixed rural and urban population), Gliwice (Upper Silesia--moderate iodine deficiency area mostly industrial with 4.89 million inhabitants) and Olsztyn (slight iodine deficiency area, mainly rural with 0.77 million inhabitants). Between 1990 and 2001, in the study area 2691 newly diagnosed cases of malignant neoplasms of the thyroid gland were registered. In over 80% of patients it was differentiated thyroid cancer: mainly in women over 40 years, with F/M ratio 5.8. The highest percentage of papillary cancer 72.9% was observed in Olsztyn and lowest--50.0%--in Krakow and Nowy Sacz districts. In this period of time incidence rate of differentiated thyroid cancer in women increased in Kraków, Gliwice, and Olsztyn from 1.51 to 9.34 in 1998 1.27 to 5.74 in 1999 and from 2.52 to 11.35 in 2001 respectively. In the youngest (0-20 years) age group no significant increase of IR was observed. Between 1998 and 2001 the dynamics of increase of the thyroid cancer incidence markedly diminished. In conclusion it was hypothesised that an increase in IR of differentiated thyroid cancer in the study area was caused mainly by the suspension of iodine prophylaxis in 1980 and was diminished by the introduction of an obligatory model of iodine prophylaxis in 1996/1997. It was modified in terms of histotype and dynamics of increase by exposure to ionizing radiation. A very specific group at risk on the population level were women aged 20-40 years in the reproductive age exposed to iodine deficiency after suspension of iodine prophylaxis in 1980 and to radiation after the Chernobyl accident in 1986.