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Neurology, Ophthalmology, Cardiology, Oncology, Obesity, Endocrinology, Vascular surgery - Causes, Symptoms, Diagnosis, Treatment, description of the disease.

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Thursday, 27.07.2017, 01:52
Main » Oncology » Causes of Cancer 
18:15
Causes of Cancer


Causes of Cancer

Scientists predict the incidence of malignant cancer in 2020 could reach 16 million against 10 million in 2000. This growth is due to aging of the population and the increase, as well as the deterioration of living, deteriorating conditions of the human environment. Consequently, the reduction in morbidity can be achieved by preventing cancer, as well as by improving the diagnosis and treatment.


The most effective interventions that reduce cancer incidence, are the fight against smoking, changes in nutrition, reduce ultraviolet radiation, mass preventive examinations (screening), the spread of the recommendations (educational activities). These measures have reduced the incidence of cancer in Europe by 15%.

How to develop cancer and other tumors? The basis of carcinogenesis, including the development of cancer is damage to the structure of DNA. Resists carcinogenesis powerful system repair (restoration) of damage. Consequently, the ability to run tumor growth will depend on the quantity and properties of carcinogen, and the quality of the recovery systems. That is why the reduction in revenue carcinogens makes a significant preventive effect, and the "bad inheritance" requires more careful monitoring of patients.

The mechanism for implementing various types of injuries in different carcinogens. For example, physical factors may have a direct damage (point change in the structure or DNA strand breaks) by transferring the excess energy as well as due to excess production of free radicals that damage the DNA structure. So behave in ultraviolet and X-ray radiation. Chemical carcinogens typically implement their action by forming chemical bonds with DNA, such as PAH-DNA adducts, DNA-benzpyrene, aflatoxin-DNA, aminobiphenyl-DNA, NNN-DNA, NNK-DNA, and many others. Biological factors (often viruses) change the structure of DNA, usually by embedding into it. Sometimes it can lead to carcinogenesis foreign bodies and chronic inflammation. Oddly enough, may contribute to carcinogenesis and medicine, making extensive use as a source of ionizing radiation and some drug treatment options (some types of hormone replacement therapy and cancer therapy).

Carcinogenesis - and often multi-stage reversible process, so the transition from one stage of carcinogenesis in the other (both forward and reverse) and depends on many external and internal factors that can contribute to and, and to counteract this process.

Early markers of carcinogenesis - is the appearance of micronuclei in the cells, chromosomal aberrations, chromatid exchanges, etc. These markers are nonspecific. More specific identification of oncogenes and tumor suppressor genes. For example, damage to the p53 gene is observed in 50% of cancer cases, but the spectrum of mutations in the p53 suppressor gene, is different and depends even on the smoking or non smoking patient. P53 mutations occur in hepatocellular carcinoma, colon cancer, brain tumors, sarcoma, lung cancer, bladder and esophageal carcinomas, adenomas, and so on proliferating Mutations in the RAS oncogene are characteristic of carcinogenesis in the colon for adenomas larger than 1 cm in tumor development is important the fact of damage accumulation. It is proved that the accumulation of damage in oncogenes and suppressor genes, with chronic exposure to carcinogens and the presence of the contributing factors leading to tumor progression and, ultimately, to its malignancy and metastasis.

Heredity may increase the risk of cancer, whether associated with the peculiarities of the metabolism of carcinogens, or with the characteristics of emerging recovery of DNA damage. For example, there is a genetic predisposition to the consolidation of mutations in the retinoblastoma gene, the gene-suppressor p53, the genes for breast cancer and ovarian cancer BRCA1, BRCA2, the genes adenomatous polyposis colon (APC), congenital nonpolyposis colon cancer (HMLH1), neurofibromatosis (NF 1) and others

The reason for 90-95% of malignant disease - environmental factors and lifestyle:
  • Smoking - the reason 30% of the pathology
  • eating habits (high-calorie diet, obesity, carcinogens in food, a small amount of fiber in the diet) - 35% of pathology
  • infectious agents (viruses, chronic foci of infection) - 10%
  • occupational carcinogens - 4-5%;
  • ionizing and ultraviolet radiation - 6-8%;
  • Alcoholism - 2-3%;
  • air pollution - 1-2%
  • reproductive (sex) factors - 4-5%;
  • low physical activity - 4-5% of all malignant neoplasms.

In line with this, cancer prevention today should include:
  • Reduce exposure to carcinogenic substances (smoking cessation, the normalization of power supply, etc.), as well as identifying markers of exposure to carcinogens, vaccination and other measures.
  • Reducing individual risk of cancer by identifying individuals at increased genetic risk.
  • Diagnosis and treatment of precancerous conditions, through the identification and treatment of persons with signs of precancer.

Intervention in the process of carcinogenesis and its possible leveling today. Information about the molecular genetic markers to detect changes in carcinogen and early cancer is constantly updated and growing. There is a possibility of cancer prevention, diagnosis and pre-clinical therapy in the early stages of carcinogenesis, which ultimately contributes to a significant reduction in the risk of malignant cancer pathology, and instills confidence in the fight against cancer pathology in the 21st century.



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