Quarter of century since the Chornobyl accident: сancer risks in affected groups of population

Probl Radiac Med Radiobiol. 2014 Sep;19:147-69.
[Article in En, Ukrainian]

Abstract
in En , Ukrainian

Objective. The goal of this study was to define levels and dynamic trends of cancer incidence at whole and some separate sites in groups of Ukrainian population affected by the Chornobyl accident during a long period of observation. Materials and methods. Those groups were Chornobyl accident recovery operation workers (CRW) of 1986-1987 years of participation, evacuees from Prypyat town and 30-km zone and residents of the most contaminated territories of Ukraine. Analysis was carried out with the standard methods of descriptive epidemiology: calculation of crude, age-specific and age-adjusted incidence rates with standard errors and confidence intervals. Results, discussion and conclusions. This study showed that all cancer incidences exceeded the national level only in CRW group. Decrease of cancer incidence rate in the recent years might be caused by shortened average life expectancy in Ukrainian population, especially in males. Statistically significant increase of leukemia incidence in CRW group was registered as well. Besides, in all three main affected groups there was revealed significant excess of thyroid cancer. Irradiation of thyroid due to radioactive iodine fallouts might be a main cause of this phenomenon. Increase of thyroid cancer incidence was registered not only in children, but also in adolescents and adults. Appearance of excess thyroid cancer cases as an effect of radiation exposure tends to increase during the time. Significant excess was also revealed for breast cancer in female CRW group. Because latency period for different nosological forms of radiation-induced malignant tumors varies widely, profound attention in further studies should be drawn not only to thyroid, breast cancers and leukemia, but also to malignancies with longer latent period: lung, stomach, colon, ovary, urinary bladder, kidney cancer and multiple myeloma.

Metoju doslidzhennja bulo vyznachennja rivnja ta dynamiky zahvorjuvanosti na zlojakisni novoutvorennja v cilomu ta na okremi nozologichni formy v grupah naselennja Ukrai'ny, jaki postrazhdaly vnaslidok avarii' na ChAES, vprodovzh tryvalogo periodu sposterezhennja. Materialy ta metody. Grupamy sposterezhennja buly uchasnyky likvidacii' naslidkiv avarii' na ChAES (ULNA) 1986–1987 rr. uchasti, evakujovani z m. Pryp’jat', 30-km zony ta meshkanci najbil'sh zabrudnenyh radionuklidamy terytorij Ukrai'ny. Analiz provedeno z vykorystannjam standartnyh metodiv deskryptyvnoi' epidemiologii': rozrahunky intensyvnyh, vikovyh ta standartyzovanyh za vikom pokaznykiv vkljuchno iz vyznachennjam standartnoi' pohybky ta dovirchogo intervalu. Rezul'taty, obgovorennja ta vysnovky. Vstanovleno, shho zahvorjuvanist' na vsi nozologichni formy zlojakisnyh novoutvoren' perevyshhuje nacional'ni pokaznyky til'ky v grupi ULNA 1986–1987 rr. uchasti. U meshkanciv radioaktyvno zabrudnenyh terytorij v ostanni roky vidmicheno znyzhennja rivnja zahvorjuvanosti, shho mozhe buty pov’jazano zi skorochennjam seredn'oi' ochikuvanoi' tryvalosti zhyttja, osoblyvo cholovikiv. Takozh bulo zarejestrovano zrostannja ryzyku zahvorjuvanosti na lejkemiju sered ULNA. Krim togo, v usih tr'oh osnovnyh grupah postrazhdalyh vyjavleno znachnyj eksces zahvorjuvanosti na rak shhytopodibnoi' zalozy. Oprominennja shhytopodibnoi' zalozy vnaslidok dii' opadiv radioaktyvnogo jodu mozhe buty golovnoju prychynoju vstanovlenogo ekscesu cijei' patologii'. Zrostannja zahvorjuvanosti na rak shhytopodibnoi' zalozy zarejestrovano ne til'ky u ditej, ale takozh u pidlitkiv ta doroslyh. Kil'kist' nadlyshkovyh vypadkiv raku shhytopodibnoi' zalozy, jak naslidku radiacijnogo oprominennja, maje tendenciju do zrostannja z plynom chasu. Suttjeve pidvyshhennja zahvorjuvanosti na rak molochnoi' zalozy bulo vyjavleno u zhinok ULNA 1986–1987 rr. uchasti. Oskil'ky latentnyj period dlja riznyh nozologichnyh form radiacijno indukovanyh puhlyn vidriznjajet'sja, u podal'shyh doslidzhennjah slid prydiljaty uvagu ne til'ky zaznachenym formam zlojakisnyh puhlyn, ale j novoutvorennjam z bil'sh tryvalym latentnym periodom: legeniv, shlunku, prjamoi' kyshky, jajeshnyka, sechovogo mihura, nyrky ta mnozhynnij mijelomi.

Keywords: Chornobyl accident; breast cancer; ionizing radiation; leukemia; malignant tumors; thyroid cancer.