| Abstract | Uloga joda u patogenezi karcinoma štitnjače je kompleksna i predmet je rasprave. U
Hrvatskoj je uvođenjem novoga zakona o obveznom jodiranju soli 1996. godine povećana
količina joda s prijašnjih 10 na 25 mg kalij-jodida po kilogramu soli. Istražili smo utjecaj
povećane jodne profilakse na epidemiološka i kliničko-patohistološka obilježja karcinoma
štitnjače. Uspoređeni su bolesnici s karcinomom štitnjače liječeni u Klinici za onkologiju i
nuklearnu medicinu KB «Sestre milosrdnice», Zagreb u petogodišnjem razdoblju prije
uvođenja novoga zakona (1988-1992, umjereni nedostatak joda, n=132) i petogodišnjem
razdoblju nakon uvođenja novoga zakona (2000-2004, dostatan unos joda, n=334).
Istražen je utjecaj povećane jodne profilakse na patohistološka obilježja karcinoma
štitnjače, omjer papilarni-folikularni karcinomi štitnjače, omjer žene-muškarci, dob
novooboljelih, veličinu i proširenost novootkrivenih diferenciranih karcinoma štitnjače, te
incidenciju i smrtnost od karcinoma štitnjače u Hrvatskoj. U statističkoj obradi korišteni
su Mann-Whitney test, χ2 test, Fischer-ov egzaktni test, Kolmogorov-Smirnovljev test i
analiza trenda. Nakon novoga zakona utvrđena je «papilarizacija» karcinoma štitnjače
obilježena porastom broja papilarnih i omjera papilarni-folikularni karcinomi štitnjače s
8.3 na 15.2 (p=0,107), omjera žene muškarci s 3.7 na 4.9 kod papilarnog karcinoma
štitnjače (p=0,325) i dobi novooboljelih od papilarnog karcinoma štitnjače s 41 na 51
godinu (p<0.001). U razdoblju dostatnog unosa joda utvrđeno je smanjenje medijana
veličine diferenciranog karcinoma štitnjače s 20 na 12 mm (p<0.001) i pomak prema
manje uznapredovalim stadijima bolesti: porast udjela T1 uz smanjenje udjela T2, T3 i T4
tumora (p<0,001) s posljedičnim smanjenjem udjela bolesnika s regionalnim i udaljenim
metastazama. Udio bolesnika s papilarnim mikrokarcinomom štitnjače se povećao s 22%
u razdoblju prije uvođenja novoga zakona na 45% u razdoblju nakon uvođenja novoga
zakona (p<0.001). Incidencija karcinoma štitnjače u Hrvatskoj porasla je u razdoblju
dostatnog unosa joda 2.5 puta u žena i 2.2 puta u muškaraca u odnosu na razdoblje
umjerenog nedostatka joda, ali je smrtnost od karcinoma štitnjače u promatranim
razdobljima ostala nepromijenjena u muškaraca, dok je u žena u razdoblju dostatnog
unosa joda zabilježen pad smrtnosti. Porast incidencije karcinoma štitnjače u Hrvatskoj ne
može se pripisati povećanom unosu joda već poboljšanoj dijagnostici. Zbog široke
upotrebe ultrazvuka i citološke punkcije otkriva se sve više papilarnih karcinoma štitnjače
u ranijim stadijima bolesti koji imaju dobru prognozu i izrazito nisku smrtnost. Tome u
prilog govori i niska smrtnost od karcinoma štitnjače u Hrvatskoj u oba spola, usprkos
značajnom porastu incidencije. |
| Abstract (english) | The role of iodine in the pathogenesis of thyroid cancer is complex and
controversial. In 1996, The New law on obligatory salt iodination was introduced in
Croatia with the increse in content of iodine per kg of salt from 10 to 25 mg. The influence
of increased iodine intake on clinical and pathohistological characteristics of thyroid
cancer was investigated. The patients with thyroid cancer treated at the Department of
Oncology and Nuclear medicine «Sisters of Charity» University Hospital, Zagreb in two
periods with diferent iodine intake were analyzed (1988.-1992., moderate iodine
deficiency, n=132) and (2000.-2004., iodine sufficiency, n=334). The influence of
increased iodine intake on pathohistology, papilllary to follicular cancer and female to
male ratio, age at presentation, size and stage of differentiated thyroid cancer, and the
incidence and mortality from thyroid cancer in Croatia were investigated. Mann-Whitney
Test, χ2 Test, Fischer's Exact Test, One-Sample Smirnov-Kolmogorov Test, and trend
analysis were used in statistical analysis. After the New law the «papillarization» of
thyroid cancer was demonstrated in Croatia with the increase in number of papillary
thyroid cancer patients, increase in papillary to follicular cancer ratio from 8.3 to 15.2
(p=0,107), female to male ratio from 3.7 to 4.9 in papillary thyroid cancer patients
(p=0,325) and age at presentation from 41 to 51 years (p<0.001) in papillary thyroid cancer
patients. Furthermore, the decrease in median size of differentiated thyroid cancer from 20
mm to 12 mm (p<0.001), and shift to less advanced tumor stages was demonstrated in
iodine sufficiency period: the increase in T1 and decrease in T2, T3 and T4 tumors
(p<0.001), resulting in lower proportion of patients with regional and distant metastases. In
iodine sufficiency period the incidence of thyroid cancer has increased in Croatia 2.5 times
in females and 2.2 times in males in comparison to mild iodine deficiency period.
However, in the observed periods mortality from thyroid cancer has remained stable at low
levels in man, and decreased in iodine sufficiency period in females. The proportion of
patients with papillary thyroid microcarcinoma has increased from 22% in mild iodine
deficiency period to 45% in the period after the new law (p<0.001).
The increase in incidence of thyroid cancer in Croatia can not be attributed to increased
iodine intake. It is primary caused by improved diagnostics. Due to wide use of ultrasound
and fine needle biopsy more and more papillary thyroid cancers are detected in the earlier
stages of disease with better prognosis and very low mortality rate. In favour of this is low
mortality rate from thyroid cancer in Croatia, in both females and males, despite
significant rise in the thyroid cancer incidence rate. |
