Cancer risk estimation in Belarussian children due to thyroid irradiation as a consequence of the Chernobyl nuclear accident.

The thyroid doses received by the juvenile population of Belarus following the Chernobyl accident ranged up to about 10 Gy. The thyroid cancer risk estimate recommended in NCRP Report No. 80 was used to predict the number of thyroid cancer cases among children during 1990-1992 in selected Belarussian regions and cities. The results obtained using this risk estimate show an excess of thyroid cancer cases being registered vs. the predicted cases. Thyroid cancer incidence rate among boys under investigation is higher than among girls in the postaccident period. The excess of the observed over the expected incidence in the general juvenile population is caused by the high thyroid cancer incidence rate among boys. These results, which can be considered part of the first stage of a thorough thyroid cancer risk estimation after the Chernobyl accident, demonstrate the critical need to complete these studies in depth.

Radiation effects on the population of Belarus after the Chernobyl accident and the prediction of stochastic effects.

Evaluation of conditions of exposure during the post-accident period makes it possible to identify two periods in the radiation exposure of Belarus's population. As a result of our investigations we obtained data about doses for four different categories in the exposed population: people who lived in the contaminated territories without evacuation and relocation; evacuated people: cleanup workers ("liquidators"); and people who were exposed in childhood, especially for thyroid exposure. The total doses for these categories in different time periods were analysed. Evaluation of doses received by the Belarusian population due to the Chernobyl accident shows no evidence of doses, that could lead to the deterministic consequences of radiation exposure. For all exposed groups we made predictions about different types of stochastic consequences of exposure.

[The distribution of HLA-system antigens in lung cancer patients]. / Raspredelenie antigenov sistemy HLA u bol'nykh rakom legkikh.

Data on 152 cases of lung cancer were studied in an attempt to identify relationship between immunogenetic markers of the HLA system, on the one hand, and histologic pattern of the disease and effectiveness of radiation treatment, on the other. Control group included 200 healthy blood donors. Eight A locus antigens and 16 B locus antigens were studied. In the entire group of patients, HLA-Aw19 antigen was observed less frequently as compared to controls. Similarly infrequent were haplotypes containing the antigen. The occurrence of HLA-B16 antigen was higher in the adenocarcinoma group. Resistance to treatment, particularly, in patients with small-cell histology was associated with the presence of HLA-B8 antigen. Possibility of tissue typing of antigens for diagnosis and prediction of response in lung cancer patients is discussed.