CHERNOBYL-RELATED CANCER AND PRECANCEROUS LESIONS: INCIDENCE INCREASE VS. LATE DIAGNOSTICS

The reported incidence of thyroid cancer in children and adolescents in Soviet Union before the Chernobyl accident was lower than in other developed countries. This is not clearly recognizable from the literature because comparisons of the high incidence figures 4 years after the accident and later have been made with those from the first years after the accident, when the registered incidence had already started to increase. Considering the low pre-accident registered incidence, there was an accumulated pool of undiagnosed thyroid tumors before the accident. The percentage of more advanced cancers, larger in size and less differentiated, was higher after the accident, when the pool of neglected cancers was diagnosed due to the screening and improved diagnostics. Some of these advanced tumors found by screening were interpreted as aggressive radiogenic cancers. The same tendency might be true also for other cancers, e.g. renal cell carcinoma. Furthermore, the screening-effect, false-positivity and registration of non-exposed patients as Chernobyl victims has obviously contributed to the registered incidence increase of malignancy

Histopathological and cytological diagnostics: a view from Russia

In the former Soviet Union, pathologists usually do not examine cytological specimens. Cytology belongs to another field of practice: laboratory medicine. Not all cytologists find enough time to compare their reports with histopathological ones, while histological and cytological specimens are hardly ever confronted; this opportunity of quality control is therefore lost. There are no nationwide programs of cervical cancer prevention. There are almost no laboratory technicians for screening of cytological smears. Overall, there are grounds for optimism: the improved economy makes it possible today to acquire modern equipment and literature, while broadening international co-operation is already attracting foreign expertise into the country

On the RET Rearrangements in Chernobyl-Related Thyroid Cancer

There is a consensus that Chernobyl accident has induced thyroid cancer increase in children and adolescents. The UNSCEAR report concluded that no somatic disorders other than thyroid cancer were caused by radiation exposure due to the accident except for acute radiation sickness occurred to the people within the Power Plant at the time of the accident. A hypothesis is discussed in this paper that the increase of thyroid cancer was caused predominantly by the screening, overdiagnosis, and registration of nonirradiated persons as Chernobyl victims. A mechanism of thyroid cancer overdiagnosis is described that can be active even today, causing hypertherapy. Older neglected tumors found by the screening shortly after the Chernobyl accident or brought from noncontaminated areas were misclassified as aggressive radiation-induced cancers. Therefore, supposed markers of the radiation-induced thyroid cancer, such as the RET rearrangements, are probably associated with disease duration and tumor progression. The screening effect is obviously dependent on the basis level of medical surveillance: the higher the level, the smaller the screening effect. Absence of any significant increase of thyroid cancer after the Fukushima accident in spite of the vigorous screening would certify the high level of health care in Japan especially for children

Testing of serum atherogenicity in cell cultures: questionable data published

In a large series of studies was reported that culturing of smooth muscle cells with serum from atherosclerosis patients caused intracellular lipid accumulation, while serum from healthy controls had no such effect. Cultures were used for evaluation of antiatherogenic drugs. Numerous substances were reported to lower serum atherogenicity: statins, trapidil, calcium antagonists, garlic derivatives etc. On the contrary, beta-blockers, phenothiazines and oral hypoglycemics were reported to be pro-atherogenic. Known antiatherogenic agents can influence lipid metabolism and cholesterol synthesis, intestinal absorption or endothelium-related mechanisms. All these targets are absent in cell monocultures. Inflammatory factors, addressed by some antiatherogenic drugs, are also not reproduced. In vivo, relationship between cholesterol uptake by cells and atherogenesis must be inverse rather than direct: in familial hypercholesterolemia, inefficient clearance of LDL-cholesterol by cells predisposes to atherosclerosis. Accordingly, if a pharmacological agent reduces cholesterol uptake by cells in vitro, it should be expected to elevate cholesterol in vivo. Validity of clinical recommendations, based on serum atherogenicity testing in cell monocultures, is therefore questionable. These considerations pertain also to the drugs developed on the basis of the cell culture experiments