Cancer Bronchial carcinomas

Cancer treatment is a multimodality treatment, i.e., surgery is combined with radiotherapy and antineoplastic chemotherapy. The latter treatment mode is used mainly for cancers which have disseminated. Different forms of cancer differ in their sensitivity to chemotherapy with antineoplastic agents. The most responsive include lymphomas, leukemias, choriocarcinoma and testicular carcinoma, while solid tumors such as colorectal, pancreatic and squamous cell bronchial carcinomas generally show a poor response. The clinical use of antineoplastic agents is characterized by the following principles. 

Thus, oxygen radical production by leukocytes can be responsible for cancer development. However, the levels of leukocyte oxygen radical generation depend on the type of cancer. For example, PMNs and monocytes from peripheral blood of patients with lung cancer produced a diminished amount of superoxide [169], Timoshenko et al. [170] observed the reduction of superoxide production in bronchial carcinoma patients after the incubation of neutrophils with concanavalin A or human lectin, while neutrophils from breast cancer patients exhibited no change in their activity. Chemotherapy of lung and colorectal carcinoma patients also reduced neutrophil superoxide production. Human ALL and AML cells produced, as a rule, the diminished amounts of superoxide in response to PMA or FMLP [171], On the other hand total SOD activity was enhanced in AML cells but diminished in ALL cells, while MnSOD in AML cells was very low. It has been proposed that decreased superoxide production may be responsible for susceptibility to infections in cancer patients. 

Statistical surveys provide an impressive correlation between the number of cigarettes smoked a day and the risk of death from coronary disease or lung cancer. Statistics also show that, on cessation of smoking, the increased risk of death from coronary infarction or other cardiovascular disease declines over 5-10 years almost to the level of non-smokers. Similarly, the risk of developing bronchial carcinoma is reduced. 

In one epidemiological study of 138 workers exposed to vinylidene chloride in the United States, no excess of cancer was found, but follow-up was incomplete, and nearly 40% of the workers had less than 15 years latency since first exposure (lARC, 1986). In a study in the Federal Republic of Germany of 629 workers exposed to vinylidene chloride, seven deaths from cancer (five bronchial carcinomas) were reported this number was not in excess of the expected value. Two cases of bronchial carcinoma were foimd in workers, both of whom were 37 years old, whereas 0.07 were expected for persons aged 35-39 years (Thiess et al., 1979). The limitations of these two studies preclude assessment of the carcinogenicity of the agent to humans. No specific association was found between exposure to vinylidene chloride and an excess of lung cancer observed in a synthetic chemicals plant in the United States. 

The main route of exposure, however, is by inhalation of the fibres. Asbestos causes three types of adverse effects asbestosis, bronchial carcinoma, and mahgnant mesothelioma. The latter two are types of cancer, with mesothelioma associated only with exposure to asbestos. The mechanisms by which asbestos causes cancer are not fuUy understood, although some features are known (see box), such as the size of fibre (only fibres of certain sizes are hkely to cause disease). All forms of asbestos can cause asbestosis and bronchial carcinoma if the exposure level and length of exposure are high enough. 

The way in which asbestos causes cancer is not clear. It may be the constant irritation it causes plus the presence of impurities in the fibres, such as iron salts, which may lead to the production of reaaive oxygen which can damage DNA. The size of the fibres again appears to be important in relation to the cancer (mesothelioma and bronchial carcinoma), with those 5 pm long and 0.3 pm in diameter being the most active. Because the fibres tend to remain in the lung tissue, a short period of high exposure could be sufficient to cause cancer. 

Fig, 37.171 Pronounced liver invasion by metastases of varying sizes partly with cancer umbilicus and neovascularization. Clinical diagnosis bronchial carcinoma... 

Tomingas R, Pott F, Dehnen W. 1976. Polycyclic aromatic hydrocarbons in human bronchial carcinoma. Cancer Lett 1 189-195. 

The chemical is banned. Crocidolite is carcinogenic in humans. Therefore all uses of crocidolite and its products are prohibited. Sufficient evidence of carcinogenicity to humans. Inhalation can cause fibrosis of the lung (asbestosis), bronchial carcinoma, mesothelioma of the pleura and peritoneum, and possibly cancers at other sites. (Reference (EP3) UNEP/FAO - PIC Circulars XIV, XV, XVI, XVII - 12/2001,6/2002, 12/2002,6/2003, )... 

It is interesting to note that in West Germany the increased occurrence of bronchial carcinomas in patients with silicosis cannot be based on statistical records (65). In other words, even if silicosis develops as a result of quartz dust, the silicosis cannot be associated with a cancerous disease. According to Mayer (69), the findings from animal experiments that showed that quartz dust also caused an increase in carcinomas cannot be applied to human beings. 

Although chronic bronchitis is frequently found among miners, the relatively low frequency of bronchial cancer among Ruhr area coalminers makes it improbable that chronic bronchitis had a dominant effect on the development of bronchial carcinoma, and therefore bronchial carcinoma should not be regarded as an occupational disease among anthra-cosilicosis patients (Schimanski and Rosmanith 1974). 

F. Trump, and C. C. Harris. 1991. Human bronchial epithelial cells transformed by the c-raf-1 and c-myc protooncogenes induce multidifferentiated carcinomas in nude mice A model for lung carcinogenesis. Cancer Res 51 3793-3801. 

In a survey of chemical plants (without prior hypothesis) in the German Democratic Republic, nine cancer cases were found in a factory where the main process was dimerization of acetaldehyde and where the main exposures were to acetaldol (3-hydroxybu-tanal), acetaldehyde, butyraldehyde, crotonaldehyde (IARC, 1995) and other higher, condensed aldehydes, as well as to traces of acrolein (lARC, 1985). Of the cancer cases, five were bronchial tumours and two were carcinomas of the oral cavity. All nine patients were smokers. The relative frequencies of these tumours were reported to be higher than those expected in the German Democratic Republic. [The Working Group noted the mixed exposure, the small number of cases and the poorly defined exposed population.]... 

The observation of excess mortality from cancer of the pancreas among US male veterans admitted to hospital for bronchial asthma and discharged on various broncho-dUators has raised the question of a possible connection to the theophylUne (see the monograph on Caffeine). Although not fuUy resolved, chronic use of theophyUine does not appear to be associated with an increased risk of esophageal or gastric carcinoma (9). 

A case-referent study of exposure to radon from the ground and bronchial cancer was carried out on 292 female lung cancer cases and 584 controls who had lived in Stockholm for 30 or more years. Lung cancer cases were diagnosed as oat cell and other types of anaplastic pulmonary carcinomas and the study concluded that radon and daughters were a significant etiologic factor in the cancers noted. 

The detection of telomerase activity or hTERT mRNA in excretion, secretion, brushings, and washings has been evaluated. In pancreatic, secretion samples, which contain freshly exfoliated cells, detection of telomerase activity was encouraging for cancer detection. Telomerase activity was also found to be useful in distinguishing between adenoma and carcinoma in intraductal papillary-mucinous tumors, which can sometimes be difficult to diagnose. In bronchial brushing samples, the clinical sensitivity of cancer detection is below 70% and false-positive results are commonly encountered because of contamination witli lymphocytes, which contain measurable telomerase activity. The measurement of telomerase is also expected to become a useful... 

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