Cancer Risk Factors
Oncology / / May 09, 2016
Age is one of the most important factors associated with the development of malignant tumors.Except for malignant tumors in children incidence increases sharply with age.The question remains whether this is only an expression of the accumulated effects of some exogenous carcinogenic factors or due to the weakening of the "resistance" of the body and its recovery mechanism.
differences in the incidence of cancer is not related to the sex organs, endocrine indicate the dependence of its development, although they can also be attributed to the different habits of both sexes.However, some observations of epidemiologists, such as increased risk of breast cancer in nulliparous women or in women with first birth at a later age, as well as during the late menopause indicate the role of the endocrine status of individuals in the development of cancer.On this point as data on a more frequent occurrence of certain forms of cancer in patients with certain endocrine diseases or metabolic disorders (eg, the relation
The role of hereditary and genetic factors causing growing concern.Examples of transformed hereditary tumor diseases or precancerous syndromes according to the laws of Mendel are rare (eg, retinoblastoma; adenocarcinoma arising from polyps of the large intestine, skin carcinoma in situ xeroderma pigmentosum, acute leukemia and malignant lymphoma of the various precancerous syndromes, etc...).However, the study of the distribution of the family of tumor diseases showed that the incidence of familial cases are also at least a rare form of cancer, especially among close relatives (parents and children).This - specific tumor localization (e.g., breast, colon), or various other locations of the tumor ( "cancer families").
observed significant racial and ethnic differences are indicative of the role of genetic, exogenous or both.However, studies show that immigrants tend to cancer, common in their country of residence, give reason to assume that the exogenous factors are more important than genetic.Genetic determinism cancer may manifest connection with certain blood groups or enzymes.Except in connection with gastric cancer blood group A, no consistent correlations were found.
should take into account some non-family malformations, which can also be caused genetically, as more and more appear evidence that children with certain birth defects are prone to cancer (for example, Down syndrome).Other defects associated with neoplastic diseases, can be attributed to genetic mutations, "spontaneous" or caused by exogenous influences.The observed coincidence between teratogenesis and oncogenesis creates the need to expand epidemiological studies in this field.
Many examples show that only a small proportion of people who are equally exposed to exogenous carcinogens (eg, in heavy smokers), the cancer develops.Apparently, it is equally important to find out why most of the people exposed to exogenous risk factors for cancer, the disease does not develop, and to identify those individuals in whom it develops.Until now, unfortunately, it was found only a few features that make it possible to objectively determine the sensitivity of individuals to cancer (eg skin cancer in light-skinned people).