Renal Cancer from Ukraine vs. Colombia and Spain

Jargin SV

Published on: 2026-03-30

Abstract

This is a commentary on the series of studies [1-7], in particular, the last one making a comparison of renal-cell carcinoma (RC) using tissue specimens from Ukraine with the control from Colombia and Spain [7]. The earlier research was commented previously [8]. RCs from Ukraine tended to be of higher grade than those from the control [1-7]. In the most recent study, the microvessel density in tumor tissue from patients residing both in “highly” and “low contaminated areas of Ukraine” [7] was higher than that in RC from Spain and Colombia (p<0.01). The difference between both Ukrainian groups was statistically insignificant. The increased angiogenesis was associated with a higher expression of the immunohistochemical marker VEGF (vascular endothelial growth factor) [7]. It was assumed that the exposure to ionizing radiation leads to an increase in the microvessel density, which in turn is associated with a higher grade and less favorable prognosis [6-9].

Keywords

Ionizing radiation; Chernobyl; Cancer detection; Renal cancer

Commentary

It was pointed out in the preceding comment that the difference in the RC grade between Ukraine and Spain can be explained by a more efficient and early cancer diagnostics in the latter country [8]. The proposed increase in the “aggressiveness” of both RC and thyroid cancer after the radiocontamination in the Chernobyl area [1,10] apparently resulted from detection by the screening of old neglected malignancies, interpreted as radiogenic tumors with the “rapid onset and aggressive development” [10]. As previously discussed in regard thyroid tumors, the differences are probably caused by the averagely later cancer diagnostics in the former Soviet Union [11,12].

Monitoring of populations exposed to low-dose low-rate ionizing radiation is important; but more attention should be given to potential bias e.g. screening effect, dose-dependent selection and, last but not least, ideological bias [13,14]. Admittedly, well-conducted epidemiological studies can account for some bias; but this has not always been the case. In the author’s opinion, the epidemiological research of populations exposed to the Chernobyl fallout would hardly add much reliable information because of inexact dose reconstructions, registration of unexposed patients as exposed, other bias and confounding factors. The following citation is illustrative: “The tumors were randomly selected (successive cases) from the laboratories of Kiev and Valencia...The tumors were clearly more aggressive in the Ukrainian population in comparison with the Valencian cases” [15]. The explanation seems to be evident: the more efficient diagnostics in Valencia. Considering results of the study [7], the same is probably true for Colombia.

A promising approach to the research of dose-response relationships are lifelong animal experiments. The life duration is a sensitive endpoint attributable to radiation exposures, which can evaluate the net harm or potential benefit from low-dose exposures within a certain range according to the concept of hormesis [16]. Of note, the suppositions about extraordinary aggressiveness of tumors from radiocontaminated areas may be conducive to the overtreatment, as it has been discussed for thyroid and bladder lesions [12,17]. Moreover, the Chernobyl accident has been exploited to strangle nuclear power [18]. After the accident, some countries, Germany in the first place, have dismantled nuclear power plants, thus strengthening their economic dependence on Russia [13].

Conflict of Interest Statement

The author declares no conflict of interest.

International Journal of Case Reports and Clinical Images

Renal Cancer from Ukraine vs. Colombia and Spain

Abstract

Keywords

Commentary

References