Pathology and proliferative activity of renal-cell carcinomas (RCCS) and renal oncocytomas in patients with different radiation exposure after the Chernobyl accident in Ukraine

During the 13-year period subsequent to the Chernobyl accident, the morbidi ty of malignant renal tumors in Ukraine has increased from 4.7 to 7.5 per 1 00,000 of total population. Cesium 137 (Cs-137) accounts for 90% of the inc orporated radioactivity in the Ukrainian population, which has been exposed to long-term, low dose ionizing radiation and 90% of the more labile pool of (Cs-137) is excreted via kidneys. The present study was performed to eva luate the histopathological features and the immunohistochemical status of proliferating cell nuclear antigen (PCNA) and K-ras in renal cell carcinoma s (RCCs) of 236 Ukrainian patients (groups I to V), which represents a vary ing degrees of internal exposure to radiation and were operated in 2 differ ent periods of time after the Chernobyl accident. The control group VI of 1 12 analog patients with RCCs was selected in Spain. The strong significant differences between the Ukrainian and Spanish groups were found in tumoral nuclear grade, in the percentage of sarcomatoid changes, the level of the p eritumoral inflammatory response as well as in the peritumoral lesions, The dramatic increase of aggressivity and proliferative activity supported by strong PCNA and K-ras expression of RCCs from Ukrainian groups, associated with chronic radiation nephropathy of peritumoral kidney tissue, showed goo d correlation with the duration of radiation exposure and confirmed the inf luence of chronic but regular and sustained low dose of ionizing radiation on renal carcinogenesis of the Ukrainian population, Int, J, Cancer 87:880- 883, 2000, (C) 2000 Wiley-Liss, Inc.