Some actual aspects of tumor induction and promotion

Summary Quantitative data on chemical carcinogenesis illustrate how difficult it is to decide whether there are thresholds for complete carcinogens. With tumor promoters there probably are safe levels, but these are difficult to determine. The results recorded in the experiments of Fibiger, in which tumors of the stomach were seen, could have been caused by the tumor-promoting effects of a biological agent.The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest Editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the authorDedicated to Professor Hermann Druckrey on the occasion of his 80th birthday     

Zur Epidemiologie und Ätiologie des Oesophaguscarcinoms in China

Ohne Zusammenfassung

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The epidemiology and etiology of esophageal cancer in China

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Stipendiaten der Alexander von Humboldt-Stiftung aus der Volksrepublik China

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The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest Editorials on actual and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author.Die Zeitschrift Journal of Cancer Research and Clinical Oncology bringt in zwangsloser Folge Editorials zu aktuellen und/oder kontroversen Problemen der experimentellen und klinischen Onkologie. Diese Beiträge geben ausschließlich die persönliche Meinung des Autors wieder.     

Extrarenal nephroblastomas

Summary The cases of extrarenal nephroblastoma published in the world literature have been tabulated and reviewed, and are discussed from a historical point of view.The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author     

Hormonal factors in human carcinogenesis

Summary A synopsis is presented of hormone-cancer relationships as seen by an epidemiologist. Emphasis has been placed on reproductive risk factors and cancers of the endometrium, ovary and breast. Although there are definite parallelisms in this regard the aetiological mechanisms for these three sites may be different.Evidence is accumulating that the protective effect of an early first birth and of subesequent pregnancies on breast cancer risk can be understood biologically in terms of interference with the occurrence of preneoplastic lesions.The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest Editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author.Presented at the EACR mecting, Copenhagen, 21 September 1983     

CEA (carcinoembryonic antigen): Its role as a marker in the management of cancer

Summary A Consensus Development Conference was held at the National Institutes of Health from September 29-October 1, 1980, to address issues concerning the role of carcinoembryonic antigen (CEA) as a marker in the management of cancer. The panel met following formal presentations and discussions to assess the issues based on the evidence presented. These issues included: Should CEA be used in cancer screening? Is CEA helpful in cancer diagnosis? What does CEA tell about the extent and outcome of cancer? Is CEA helpful in monitoring cancer treatment? This paper constitutes the panel's findings.The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest Editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author. The EditorsThis paper is the official report of the panel members, listed above, resulting from the National Institutes of Health Consensus Development Conference on CEA (Carcinoembryonic Antigen): Its Role as a Marker in the Management of Cancer. This consensus conference was sponsored by the National Cancer Institute, assisted by the Office for Medical Applications of Research, Office of the Director, National Institutes of Health, Bethesda, MD, USA. The conference was organized by Dr. K. R. McIntire and Mr. L. P. Greenberg, Diagnosis Branch, National Cancer Institute, Bethesda, MD     

Zur Rolle der enzymatischen DNA-Reparatur bei Carcinogenese und Krebschemotherapie

Ohne ZusammenfassungCancer Research and Clinical Oncology publishes in loose succession Editorials and Guest Editorials on actual and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author. The EditorsDie Zeitschrift für Krebsforschung und Klinische Onkologie bringt in zwangloser Folge Editorials zu aktuellen und/oder kontroversen Problemen der experimentellen und klinischen Onkologie. Diese Beiträge geben ausschließlich die persönliche Meinung des Autos wieder. Die HerausgeberHerrn Prof. Harold P. Rusch, Madison, Wisc., in aufrichtiger Verehrung zum 70. Geburtstag gewidmet     

The problem of thresholds in chemical carcinogenesis some views on theoretical and practical aspects

Conclusions I have tried to show that the threshold problem for carcinogens is still unsolved and that this unsatisfactory situation creates many problems for the scientific evaluation of the carcinogenesis problem as well as for its regulative aspects. In view of the extremely low acceptance of cancer risks in the general population, which is justified as well as understandable, carcinogenesis research must present new ideas to come nearer to a solution of such problems. More sound data on dose-time-effect curves in the low incidence range of 10-0.1% tumor incidences could indicated whether the established linearity in the higher incidence range might eventually by interrupted. Increase of animal numbers could also increase reliability of carcinogenicity experiments and allow the detection of low-dose effect; the disadvantages of this approach (mega-mouse experiment) however, in regard to cost and space necessary are evident. Increases of the mean life span by optimization of animal husbandry still would be another way of approach. However, no real breakthrough is to be expected here.The most promising approach seems to be the use of other indicators for carcinogenicity instead of tumor formation. Binding studies of carcinogens to biopolymers (Neumann 1980), especially DNA, as well as the determination of preneoplastic, enzyme-deficient islands (Kunz et al. 1978) have been shown to give dose-response curves parallel to the corresponding curves from carcinogenicity studies (Kunz) and extendable over 6 orders of magnitude of doses, without deviation from linearity (Neumann). Additional parameters might be found, which, altogether, might prove to be an important step toward further knowledge in this important field of carcinogenesis research.Oh König, das kann ich dir nicht sagen, und was du frägst, das wirst du nie erfahren R. Wagner, Tristan und IsoldeJournal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest Editorials on actual and/or controversial problems in experimental and clinicial oncology. These contributions represent exclusively the personal opinion of the author. The Editors Die Zeitschrift Journal of Cancer Research and Clinical Oncology bringt in zwangloser Folge Editorials und Guest Editorials zu aktuellen und/oder kontroversen Problemen der experimentellen und klinischen Onkologie. Diese Beiträge geben ausschließlich die persönliche Meinung des Autors wieder.     

Epidemiology and the prevention of cancer: some recent developments

The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest Editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author. The Editors     

The ability of heat stress and metabolic preconditioning to protect primary rat cardiac myocytes

Primary rat cardiocytes were subjected to either thermal preconditioning for 30 min at 43°C or 20 min metabolic preconditioning (10 mM deoxyglucose, 20 mM lactate, pH 6.5). Eighteen hours later cells were analysed either for hsp 70i expression or subjected to a subsequent lethal heat stress or simulated ischaemia (10 mM deoxyglucose, 20 mM lactate, 0.75 mM sodium dithionite, 12 mM potassium chloride, pH 6.5) for 2 hours and assessed for survival by trypan blue exclusion.Hsp 70i was induced over 100 fold by thermal preconditioning and 30 fold by metabolic preconditioning (p<0.001, p<0.05), hsp 90 was induced 2.71 fold and 2.24 fold (p<0.001, p<0.001) by thermal and metabolic preconditioning respectively, while hsp 60 was not induced by either treatment. Preconditioned cultures had improved survival against subsequent lethal heat stress or simulated ischaemia: Thermal preconditioning reduced death from 69.22% to 52.46% upon subsequent lethal heat stress and from 49.13% to 36.66% upon subsequent lethal simulated ischaemia. Metabolic preconditioning reduced cell death from 51.29% to 33.8% against subsequent lethal heat stress, and from 69.09% to 55.61% upon subsequent lethal simulated ischaemia. A second marker of cell death, the release of lactate dehydrogenase activity into the culture media, was reduced to 65% and 60% of control values for thermally preconditioned cells subjected to lethal heat or lethal simulated ischaemia respectively. Metabolically preconditioned cells demonstrated lactate dehydrogenase activity of 59% and 51% that of control values, when subjected to lethal heat or lethal simulated ischaemia respectively.Abbreviations hsp heat stress protein - hsp 70i inducible 70 kDa heat stress protein - LDH lactate dehydrogenase - PBS phosphate buffered saline     

Radioimmunotherapy: no news from the newcomer

The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the authors     

Partial responses to antineoplastic drug therapy: What do they mean?

The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author     

Clinical implications of current studies in carcinogenesis

Summary Carcinogenesis probably proceeds through a succession of cellular events. Understanding of these events may provide a rational basis for the development of anticarcinogenic treatments. These will be designed to reverse or delay the evolution of a tumor before the stage at which invasion develops. The design and conduct of trials of such agents will be easiest if they are aimed at relatively late stages in the carcinogenic process.Recent research on viral and cellular oncogenes, growth factors, and the cellular mechanism of action of phorbol ester tumor promoters raises the hope that each will be understood and related to the others by their effects on different components of a set of central controls for cellular growth and differentiation. This may ultimately provide a means for rational design of anticarcinogenic treatment. Understanding is still very far from complete, however, and we are still a long way from potential clinical application. An immediate alternative to the long-term rational approach is an empirical one based, for example, on the use of retinoids. The design and interpretation of empirically based trials of anticarcinogenic agents requires careful thought.The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest Editorials on curent/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author.Based on a lecture to the Grand Council of the European Organisation for Research and Treatment of Cancer, November 1983     

Human exposure to genotoxic carcinogens: methods and their limitations

The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author The Editors.     

Phase 1 trials of intensive antineoplastic therapy: a need for a critical reassessment of who should be treated

The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author     

Local and regional immunotherapy of cancer with interleukin 2

Conclusion The results obtained in preclinical systems as well as the first clinical trials suggest that local IL-2 immunotherapy may represent a novel approach to the treatment of some neoplasms. However, the experimental results should be confirmed and substantially extended before definitive conclusions can be drawn. We hope that the data and considerations discussed in this article will facilitate thoughts concerned with future clinical IL-2 trials and be instrumental in the optimization of IL-2 cancer immunotherapy.The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author     

Sequence rearrangements and genome instability

Summary A substantial part of the mammalian genome is composed of sequences that do not contain structural genes. These sequences may constitute the major target for physical, chemical and biological DNA-damaging agents and can be involved in carcinogenesis. DNA-damaging agents contribute to the instability of the genome by introducing recombination-prone sites at DNA; these agents lead to extensive chromosal lesions and rearrangements of genes and their regulatory sequences. Movable sequences that exist and operate in certain bacteria, yeast, and the fruit fly are responsible for sequence rearrangements and contribute to the majority of mutations. Their presence and role in higher animals is not well established. Extensive chromosomal rearrangements were identified in numerous malignancies in man and animals and definitly seem to represent a characteristic of malignancy. Vast chromosomal damage and sequence reshuffling may be of no less importance in the malignant transformation than the point mutation of a particular gene.The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest Editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author.     

The role of colony-stimulating factors in acute leukemia

Summary This article summarises the effects of colony-stimulating factors and related molecules on leukemia blasts by focussing on autocrine and paracrine growth control. This information may lead to a better understanding of the pathobiology of this highly malignant disorder, and may have therapeutic implications.Abbreviations used GM-, G-, M-CSF granulocyte-macrophage, granulocyte and macrophage colony-stimulating factors - IL interleukin - AML-CFU acute myelogenous leukemia colony-forming unit - HGF hematopoietic growth factor The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author.     

Cancer of unknown primary site

The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author the editors.     

HIV-associated Kaposi's sarcoma: new developments in epidemiology and molecular pathology

Summary New epidemiological data give evidence for an unknown etiological agent of Kaposi's sarcoma (KS). Experimental support is provided by research on cultivated KS cells. These results contradict a direct involvement of HIV-1 in the pathogenesis of KS. Research on cultivated KS cells confirmed the hypothesis that KS spindle cells originate from endothelial cells and gave new insight into the pathogenesis of tumor cell growth. KS spindle cells secrete an autocrine acting growth promoting activity. Nevertheless, they seem to depend on several growth factors like PDGF and IL-6 provided by surrounding endothelial cells and macrophages, respectively. The results support the hypothesis of a tumor relying on paracrine acting factors more than on autocrine acting factors.Abbreviations KS Kaposi's sarcoma - AIDS acquired immune deficiency syndrome - HIV human immunodeficiency virus - PDGF platelet-derived growth factor - CMV cytomegalovirus - FGF fibroblast growth factor The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author The Editors.     

The contribution of epidemiology to the study of occupational cancer

Summary Most chemical compounds and physical agents recognized as human carcinogens were first identified in the occupational environment by epidemiological studies. Some 2%–8% of all cancers have been attributed to occupational exposures, but the limitations of such estimates should be recognized. The use of existing medical information systems on occupational cancer for hypothesis generation may be improved by comparing the results emerging from different countries. An initiative in this direction is recommended. Clues emerging from such general systems should be submitted to further studies to test specific hypotheses concerning risk factors. Record linkage is necessary for the epidemiological study of occupational cancer. Efforts must be made towards the storage of identifiable records with information on occupation and cancer occurrence.The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest Editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author.