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From the oncologic point of view, imaging diagnostic techniques have been and will be of steadily increasing significance. This paper gives a survey of the present state of the art and of various aspects of current international trends in X-ray diagnostics, computed tomography, ultrasound and magnetic resonance. High tech developments raise the expenditures, so that the cost-benefit-relations have to be considered in future diagnostic strategies. Some aspects for further research tasks are mentioned. The aim of all improvements in imaging procedures is to increase the influence of diagnostic procedures on treatment planning and to improve the treatment results and, ultimately, the prognosis of cancer patients.

The development of noninvasive imaging methods with high diagnostic accuracy in the last decade has led to a new determination of the role of angiographic techniques in oncologic diagnosis. The disadvantages of angiography are discussed and the major indications in tumor diagnosis are delineated: preoperative vascular mapping, vascular involvement of the great vessels, CT and ultrasound equivocal, selective blood sampling and interventional procedures. The increasing importance of interventional radiology in oncology is emphasized.

In CMEA countries among all malignant neoplasms lung cancer ranks as a first both in incidence and mortality followed by stomach, breast and cervical cancer, lung and breast cancer being on increase, while stomach and cervical cancer have been decreasing. To the most important causes of cancer belong smoking, excessive alcohol consumption, certain occupational exposures, ambient-air pollution. Therefore, the priorities in cancer prevention and control in the CMEA countries should be directed towards complete removal or reduction in the exposure to these risk factors. Modification of diet, most probably, would reduce the frequency of some of the aforgoing cancers and first of all cancer of the stomach.

In order to clarify whether or not Dichlorvos (DDVP)--which did not exert carcinogenic effects in mice in our experiments--is cocarcinogenic, male and female mice of the strain C57Bl/6/Bln were subcutaneously injected with the carcinogen N-Nitrosodiethylamine (NDEA) and received in addition DDVP orally. For comparison NDEA and DDVP alone was administered to other groups of mice. The combined application (NDEA + DDVP) did not result in increased incidences of tumors and preneoplastic lesions as compared with the NDEA-treated groups of mice. The incidence of focal (transitional cell) hyperplasias of the urinary bladder epithelium was increased in the groups treated with NDEA + DDVP as compared to the groups with single compound treatment. There were no development of tumors and no differences in the latency periods of tumors which could be attributed to the combined treatment with NDEA + DDVP. Under these experimental conditions DDVP was not cocarcinogenic in mice.

Using mice BDF1 it has been shown that the period of retention of Doxorubicin (Dx) is shorter in the leukemia P388 cells with induced antibiotic resistance (P388/Dx) as compared to P388 cells sensitive to Dx. Administration of Verapamil (Vp) to animals leads to an increase of Dx concentration in the leukemia P388/Dx cells during a 240 min observation period. Vp promotes the therapeutic effect of Dx on P388/Dx bearing mice. It can be suggested that the mechanism of Vp action consists in the damaged Dx elimination from cells with induced resistance, since Vp doesn't change the period of circulation of the antibiotic in the blood plasma of mice.

A single application of trypan blue 3 to 24 hours before or simultaneous with inoculation of the Rauscher leukemia virus (RLV) resulted in enhancement of leukemogenesis with an especially high viremia. Repeated administration of trypan blue after RLV infection resulted in reduced spleen weight. Viremia, however, was also increased compared with controls (no application of trypan blue), but in a lower rate than in mice treated with the virus plus trypan blue. Since trypan blue is known as an inhibitor of the functions of macrophages the results point at an important role of this cell type in preventing infection with this oncogenic retrovirus. In this regard there are differences in the role of macrophages in human immunodeficiency virus (HIV) infections.

A short survey is given about the current developing methods of endosonography and their potential use in tumor diagnosis. Own results are presented in preoperative staging of rectal cancer with endorectal ultrasound.

Amplification is one mechanism for activation of oncogenes and results in an excess of DNA template, which can lead to overproduction of oncogene-specific RNA and protein. Amplification of oncogenes has been observed in different tumor tissues. In certain cases amplification and overexpression of particular oncogenes have been correlated with tumor progression and clinical behavior. The best example is neuroblastoma in which the N-myc oncogene frequently is found to be amplified. Over 1,000 patients with breast cancer have been studied for amplification of the c-erbB-2 oncogene until now. The evidence from the studies that amplification of c-erbB-2 is correlated with poor prognosis is in our opinion not convincing. More and more investigations about oncogenes and disease prognosis will take place rather at the protein level than at the DNA level.

Technical progress has produced a variety of novel imaging techniques (digital projection radiography, X-ray-transmission computed tomography, sonography, single photon emission computed tomography, positron emission tomography, magnetic resonance imaging), and has enormously extended the diagnostic possibilities in industrialized countries. Further technological developments will be considered under three aspects: --Improvement of current imaging procedures and opening-up of new applications --introduction of new imaging techniques --progressive use of computer technology in imaging diagnostics [digital image generation, image processing, image archiving and communication systems (PACS)] Finally, several consequences emerging from these aspects will be discussed.