INVESTIGATION INTO THE STRUCTURE OF SOME ONCOHEMATOLOGICAL DISEASES IN INDIVIDUALS CONTEMPORARY WITH THE CHERNOBYL ACCIDENT

Koval S.V.

• R.E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology, NAS of Ukraine, Kyiv, Ukraine

Objective: to analyze proportions of myeloproliferative diseases and acute leukemia (AL) in individuals born around the time of the Chernobyl accident and to compare it with the corresponding data of age-matched control group. Object and methods: analysis of chronic myeloproliferative diseases and acute leukemia (AL) was performed in two groups of patients of different sexes. The Critical Group was formed of the patients who were 0–4 years old at the time of the accident; the group was under follow-up from 1996 to 2015 including. The Control Group (conditional control) included both patients born before the accident and who were just over 4 years at the time of the accident, and those born a few years after the accident. Applying cytomorphological, cytochemical and immunophenotypic methods, smears of peripheral blood and bone marrow were analyzed. Results: in patients contemporary with the accident, among all types of myeloid neoplasms, the frequency of myelodysplastic syndromes (which may be the first signs of ionizing radiation long-term effects) increased. During the first five-year follow-up period (1996–2000) in the Critical group, acute lymphoblastic leukemia (ALL) significantly outnumbered acute myeloid leukemia (AML) among the types of AL in males and females. This can be attributed to the distribution of AL types in this time-age period (contemporary with the accident patients were from 10 to 18 years old). Over the next five five-year follow-up periods (2001–2005, 2006–2010, 2011–2015), a significant predominance of AML in female patients was observed. The distribution of AL types in males is somewhat different: the fraction of ALL was higher throughout the study period and only slightly smaller than that of AML in 2011–2015. Similar trends were found in the corresponding Control groups of patients of different sexes. Conclusions: analysis of the distribution of the main types of myeloproliferative diseases and acute leukemia in the groups of patients contemporary with the accident (taking into account the data of intra-laboratory analysis of these nosological forms in general in patients of Ukraine who showed a predominance of acute and chronic lymphoproliferative diseases in general structure of male oncohematopathology, and an increase in myeloproliferative neoplasms fraction among female oncohematopathology diseases) may indirectly point to the possibility of involving different histogenetic and molecular-genetic mechanisms in the development of oncohematological diseases in patients of different sexes in the post-Chernobyl period.