MALIGNANT TUMORS IN PEDIATRIC POPULATION OF UKRAINE: TRENDS AND STRUCTURAL FEATURES.

The creation of a central bank of personalized information of cancer patients, including children, allowed to obtain objective data and establish continuous cancer surveillance in the child population in Ukraine. The aim of the study was to analyze the dynamics of cancer incidence (1989-2019) and mortality (1999-2019) based on the 3rd revision of International Classification of Childhood Cancer (ICCC-3). MATERIALS AND METHODS: A study cohort includes 31,537 patients aged 0-19 years at the time of diagnosis in 1989-2019, registered in Ukrainian population. RESULTS: The major groups of malignancies in the child population are presented by leukemia, lymphomas, central nervous system (CNS) tumors, epithelial neoplasms, bone cancer and soft tissues sarcomas. There were observed no gender differences in cancer incidence, except germ cell tumors and trophoblastic tumors, gonadal malignancies, as well as some other malignant epithelial neoplasms, with their proportion being twice higher in the female population. Our analysis showed a trend towards increase in the incidence of leukemia, CNS neoplasms, neuroblastoma, trophoblastic tumors and epithelial malignancies; decrease in the incidence of lymphomas and bone neoplasms; stabilization in the incidence of malignancies of liver and kidneys. The dynamic changes in cancer mortality in the studied cohort were observed, namely, the decrease of mortality from leukemias and lymphomas in males (but not in females), along with the increase of mortality from CNS neoplasms, neuroblastoma, soft tissues sarcomas and germ cell tumors, regardless of gender. CONCLUSIONS: The analysis and presentation of the epidemiological data on children's malignancies implementing ICCC-3 classification for all relevant records in the National Cancer Registry of Ukraine allows for evaluating the major trends of cancer incidence and mortality in Ukrainian pediatric population, taking into account tumor morphology, topography, gender and age.

Incidence and long-term effects of treatment of malignant germ cell neoplasms in Ukraine.

AIM: To describe incidence of malignant germ cell neoplasms (GCNs) in Ukraine and assess the medical care to patients with GCNs and its efficacy. MATERIALS AND METHODS: Records on 6495 males and 1038 females with malignant GCNs diagnosed in 2000-2013 extracted from the database of National Cancer Registry of Ukraine have been analyzed using methods of descriptive epidemiology and survival evaluation. RESULTS: In Ukraine, GCNs covered 79.1% of testicular cancers and 48.9% of ovarian cancers in patients aged 0-19 years, while their proportions in total cancer incidence did not exceed 0.7% in males and 0.1% in females. Most of GCNs in males (75.9%) were diagnosed at the reproductive age (20-49) and in females 72.2% of GCNs were diagnosed at the age of 0-44 years. Female gonadal GCNs were divided by germinomatous and nongerminomatous as 49.3% vs 50.7% while in males this proportion was 65.3% vs 34.7%. Age-specific incidence of genital GCNs in Ukraine reached peak values in males aged 25-39 years and in females aged 10-24 years. Nonseminomatous testicular GCN cases were more common than seminomatous cases in males until the age of 30 years with an incidence of seminomas peaked 10 years later than non-seminomas. Ovarian germinomas were more common than non-germinomas in females aged 15-29. Total GCN incidence rate in 2013 was 1.99 ± 0.090/0000 in males and 0.32 ± 0.040/0000 in females, being closer to that in the countries of Eastern Europe and Asia. In Ukraine, 5-year survival of patients with testicular GCN of stage I who received surgery combined with chemotherapy or radiotherapy was lower than that reported for Europe and USA, and substantially lower in patients with stages II-IV. Five-year survival of patients with ovarian GCN treated with surgery plus chemotherapy was close to that reported in a study for populations of European countries. CONCLUSION: The trends and patterns of GCN incidence in Ukraine are similar to those in other European countries, while patterns of treatment and survival in Ukraine are closer to that in countries in transition. Further research and analysis are impossible without due registration of both the diagnosis and the treatment undertaken as well as close follow-up of patients' life status.

INCIDENCE OF MALIGNANT NEOPLASMS AMONG RESIDENTS OF SMALL RADIONUCLIDE-CONTAMINATED CHORNOBYL DISTRICTS IN A POST-ACCIDENT PERIOD. / ZAKhVORIuVANIST' NA ZLOIaKISNI NOVOUTVORENNIa MEShKANTsIV MALYKh ZABRUDNENYKh RADIONUKLIDAMY TERYTORIAL'NYKh ODYNYTs' ChORNOBYL'S'KOGO REGIONU U VIDDALENOMU PISLIaAVARIINOMU PERIODI.

OBJECTIVE: To assess the level of risks of development of malignant neoplasms among the residents of smallChornobyl districts («rayons¼) in connection with low-dose radiation exposure and its dynamic changes. MATERIALS AND METHODS: The study population included residents of Borodianka, Ivankiv and Poliske districts ofKyiv region («oblast¼) and Luhyny, Narodychi and Ovruch districts of Zhytomyr region, 175,100 inhabitants in2017. The study period was 1980-2017. All cancers incidence rates as well as rates of potentially radiation-associated sites (breast, thyroid, hematopoietic and lymphoid systems) were calculated and analysed. Methods of variation statistics, descriptive and analytical epidemiology were used. RESULTS: The impact of ionizing radiation on population of the most radionuclide-contaminated districts raisesconcerns of the potential threat of adverse cancer effects, especially thyroid cancer. The average total whole-bodyeffective radiation doses received due to cesium during long time (1986-2005) among residents of the study districts (7.6-45.8 mSv) exceeded that in Zhytomyr (5.9 mSv), Kyiv (4.9 mSv) regions and Ukraine as a whole (2.48mSv), but also in other districts in the North Ukraine. The average doses of internal radiation absorbed by the thyroid gland (161-1559 mGy) among the most vulnerable population - children and adolescents (aged 0-18 yearsat the time of the accident) of these areas, and obtained in the short post-accident period, significantly exceedthat in Zhytomyr (87 mGy), Kyiv (81 mGy) regions and Ukraine as a whole (19 mGy). Irradiation rates of adult residents of these territories were lower, but significantly exceeded the average doses received by the population ofUkraine and large administrative units. Overall cancer incidence in the 6 districts during pre- and post-accidentperiods was lower comparing to Ukraine's and Kyiv region's rates, and did not significantly differ from Zhytomyrregion's rates. At the same time, the incidence rates of thyroid cancer significantly exceeded that of the pre-accident period as well as Zhytomyr region's rates. CONCLUSIONS: The results of the study indicate needs for further monitoring of malignant neoplasms not only inthe population of Ukraine as a whole and its large administrative-territorial units, but also among residents of particular areas, given the likelihood of the realization of the risks of radiation-associated diseases in the distantpost-accident period in accordance with local environmental conditions.

EPIDEMIOLOGY OF BREAST CANCER IN UKRAINE WITH CONSIDERATION OF THE FACTORS OF THE CHORNOBYL ACCIDENT. / EPIDEMIOLOGIIa RAKU MOLOChNOÏ ZALOZY V UKRAÏNI Z URAKhUVANNIaM FAKTORIV RYZYKU ChORNOBYL'S'KOÏ AVARIÏ.

OBJECTIVE: Assessment of the possible impact of the Chornobyl accident on the incidence of breast cancer in the female population of Ukraine as a whole and in some affected groups. OBJECT OF THE STUDY: The female population of Ukraine as a whole and in separate groups of victims - women par- ticipating in the clean-up works in 1986-1987, evacuaees from the exclusion zone and inhabitants of the territo- ries most contaminated with radionuclides. METHODS: Statistical, mathematical, cartographic. RESULTS: This study, covering a significant period of time (1976-2016), revealed a steady temporal and territorial agglomeration of regions with a higher incidence of breast cancer in the southern and south-eastern regions of Ukraine. Lower - in the western and northern regions. There is a steady increase in the incidence rate, but in recent years this growth has slowed down. The epidemiological situation regarding the incidence of breast cancer in the female population of Ukraine during the 30 years after the Chornobyl accident is generally stable. At the same time, a marked increase in the frequency of this pathology in the groups of the affected population, especially in women, participated in clean-up works in 1986-1987. CONCLUSIONS: A stable agglomeration of regions with high levels of incidence in the south and south-east, and low in the west and north of the country is determined. The dynamics of breast cancer in Ukraine as a whole is characterized by steady growth, although in recent years its pace has slightly decreased. Among the individual population groups affected by the Chornobyl catastrophe (female liquidators, evacuated women from the exclusion zone, residents of the most contaminated with radionuclides territories) only among female liquidators of 1986-1987 the significant in- crease was observed in the incidence of breast cancer, which exceeds the national indicators at 1.3-1.6 times.

Experience of study of the incidence of malignant neoplasms population in small areas of Ukraine, which suffered contamination with radionuclides due to the Chornobyl accident. / Dosvid doslidzhennia zakhvoriuvanosti na zloiakisni novoutvorennia naselennia malykh terytorii Ukrainy, shcho zaznaly zabrudnennia radionuklidamy vnaslidok avarii na Chornobyl's'kii AES.

GOAL OF THE STUDY: to evaluate the dynamics of implementation risks of malignant tumors in some small areas of Ukraine in the pre- and post-accident period. MATERIALS AND METHODS: The study population group - the population of the Malyn rayon, Zhytomyr region. The period of observation covered 1980-2014. There was investigated the incidence of malignant tumors in general and individual nosological forms (thyroid cancer, breast cancer, tumors of hematopoietic and lymphoid system). Methods of variation statistics and descriptive epidemiology were used. RESULTS: Characteristics of ionizing radiation influence on the population of Malyn rayon indicate the potential for negative effects, especially for thyroid cancer. Besides the fact that the average total effective radiation dose whole body by radioactive cesium in Malyn rayon population (5.9 mSv) are at medium level in Zhytomyr region and is significantly lower in comparison with those of other areas of the northern part of the oblast, the exposure of thyroid 236 mGy, is significantly higher than the regional figures - 81 mGy. Although the level of morbidity Malyn rayon of malignant tumors in general was about at the national level for 1999-2003 and lower it in the 2012-2014, exceeding the figures of Zhytomyr region, the incidence of thyroid cancer in the 2012-2014 in Malin area was 1.7 times higher in comparison with data for Ukraine and in 1.9 times in comparison with the data in Zhytomyr region. As in most northern areas that fell under radioactive iodine fallouts, there is the realization of increased radiation risk of cancer of this organ. The incidence of breast cancer in female population Malyn rayon is the lowest in comparison with Ukraine and Zhitomir regions. However, the rate of increase in this area is the highest. CONCLUSIONS: The results indicate the need for further monitoring of occurrence of cancer cases in the population of not only Ukraine as a whole, or large administrative units, but also among the population in small areas, taking into account the probability of the realization of risks of radiation-associated disease cases according to local environmental conditions.