Cancer-Risk Factors
Cancer is a disease which is a cell proliferation mechanism awry and uninterrupted. It mentions, in Europe and North America, prevalence of lung cancers, 90% attributable to smoking, colorectal cancers, related perhaps in part eating, end breast cancers, with causes still less clear. Africa stands out frequency of liver cancer in endemic areas for Hepatitis B and that of cervical cancer in countries where birth rate is still high and where hygiene is deficient, which has as a consequence a high sexually transmitted diseases (Papilloma and herpes), which may be the origin of these cancers.
Causes of cancer
Cancers are caused by exposure to viruses, to natural or chemical substances, radiation. This has the effect of inducing mutations or inappropriate expression of different genes called oncogenic involved in cell proliferation in their differentiation and regulate these phenomena. Oncogenes are normally under the control of inhibitory genes, antioncogenele, which may be lost or may themselves suffer a mutation in actun agents enumerated above, their function is reduced in this case. But these are deprived antioncogene hereditary, which explains in part the existence of familial predisposition to cancer..
Alcohol
In man, alcohol is a risk factor for mouth cancers, the pharynx, the esophagus and liver (increased risk varies between 2 and 15% after the amounts drunk after authorities reached). Finally, the combined effect of alcohol and tobacco meet higher risk than the amount of risk taken separately (multiplicative effect). A number of studies show that there is an increased risk of breast cancer in women who drink alcoholic beverages, compared with those not drinking these drinks.
Diet
Studies have drawn attention to the role nutrition in the genesis of certain cancers, Food is criminalized as such (fat), The deficiency (fiber Vitamins) or intermediate contamination . The role of fats in carcinogenesis especially for suspected colorectal cancer, but breast cancers, the endometrium and prostate. Studies have revealed an increased risk in parallel with the consumption of fat, but revealed a protective effect of fruit and vegetables, In terms coffee role cancers of the pancreas, it could not be proved. Nitrite, from salt used for food preservation, are accused would increase the risk of stomach cancer. Aflatoxin, contaminating stored food in warm and humid, is incriminated in the primitive liver cancers, in association with virus Hepatitis B.
Irradiation
In 1944, a newspaper revealed that radiology died of leukemia ten times more than other doctors. At the atomic bombing survivors from Hiroshima and Nagasaki in 1945, the first cases of leukemia were observed in 1941, with a peak in 1951-1952. Were observed in other cancers abnormally high number in 15 years after exposure and some longer meet today, the survivors have received more than 1 gray (unit of radiation dose). In this case, there was a significant increase of cancer, which varies by irradiated tissues: mainly affected bone marrow, thyroid, breast, bone. Leukemia occurring on average 8 years after irradiation causal, sarcomas and 20 years after she and other tumors in 30-40 years after irradiation.
Radiation protection legislation has allowed to disappear occupational hazards, particularly to radiologists, the fillers and workers at nuclear plants. In addition, advances radiology medical imaging and new methods have reduced the risks of x-rays for patients.
Diseases
Some rare diseases are accompanied by an increased risk of cancers that specifically affect certain organs . They may give a date of birth malignancy that are either their only manifestation or is a manifestation of the syndrome, a disease or give birth nontumors but with high probability of malignant transformation .
Cancer drugs
Attention to the role of hormones cancer was drawn from cancer of the vagina in girls born to mothers who received diethylstilbestrol (estrogen) in the first 3 months of pregnancy. When estrogens are used as contraception, Which is associated with progestogens, the risk of breast cancer occur is substantially the same user and neutilizatoare. Use of oral contraceptives brings some reservations regarding the duration of use before a first use tasks and use by women affected by benign breast disease. But U.S. investigations conducted on a population of women at menopause and who received estrogen treatment, showed an increase in the order 4-8 times the risk of cancer of the uterine body - this increase is directly related to dose and duration of estrogen therapy. However, using current estroprogestativ seems to have made the risk go away, even to prove that they are protective.
Besides hormones, drugs that revealed an increased risk of cancer are mainly anti cancer and derivatives arsenic.
Family predispositions.
Note in some cancers familial predisposition. Thus, family members including a person affected by cancer of the colon, ovary or breast shows a 2-4 times greater risk than others to be affected by the same cancer. This increased risk is still small and probably can be explained by a mechanism that depends on several genes, resulting in a tendency which should be added the risks of environmental factors.
Solar radiations
How to tan in recent decades is accompanied, in all countries, a strong increase in the incidence of skin tumors, carcinomas and melanomas. Role radiation U.V. (UV), particularly of UVB, the shorter the wavelength and the most harmful in skin tumors was highlighted both by epidemiological observations, and by experimental models. Skin cancers are more common in subjects with light skin.
Carcinogens. In 1975 was established the relationship between exposure to soot sweeper and occurrence of cancer of the scrotum. In 1985, a large number of bladder cancer was reported in dyes industry workers. The latest evaluations of the International Center for Research on Cancer show that, of 707 tested chemicals and industrial processes, processes 7 and 23 substances have been shown to be carcinogenic to humans.
Tobacco.
Spectacular explosion of respiratory cancers at attention, 40 years ago, the role Tobacco. According to numerous epidemiological surveys, tobacco is responsible for approximately 90% of lung cancers. The risk is even more important as people smoke more, for a long time with how to inhale more smoke and more smoke as it starts young. Filter reduces risk, it grows black tobacco. Finally, we must mention an increased risk of bronchopulmonary cancers in people living in an environment with smoke (passive smokers).
Viruses.
Role of retroviruses is now well established in animals, in humans, our knowledge, only Retroviruses H.I.V. (AIDS) and HTLV (Leukemia) seem to have an oncogenic potentiality. Instead, it specifies the role of certain DNA viruses (deoxyribonucleic acid) In the development of human cancers.
The first link between the virus and emphasized that cancer was a virus family Herpesviridae (Epstein-Barr virus) With the African's lymphoma Burkitt (1964) The same virus was two years later, the impugned nazofaringeal cancer. In 1978, was referred to the connection between hepatitis B virus (HBV) and primitive cancer liver when according to geographical distribution was observed between high-risk areas and those with hepatocarcinoma Hepatitis B. The ratio papillomaviruses (HPV) and cervical cancer is the third system-cancer virus. For many years, showed the role of sexually transmitted viral diseases in developing cervical cancer. Accumulate elements to highlight predominant role of HPV
Symptoms
Their own multiplicity and specificity of cancers are difficult to list all symptoms. However, a significant weight loss and more or less rapidly, a lack of appetite, a feeling of intense fatigue, a blood loss in stools or mouth.Finally there are signs different functional pain may be associated with this cancer. Development often silent cancers tend to delay diagnosis and lead to problems doctors see patients not only in an already advanced stage of disease. Sometimes a disease is discovered accidentally, during a medical visit or a examination of blood. The diagnosis is made by clinical examination, by laboratory tests, radiological examinations and by endoscopic by biopsies.
Evolution
Once triggered by activation of oncogenes, which have suffered or mutation, and because of the loss or alteration by mutation of one or more antioncogene, cancers suffer a cancerous growth which makes them increasingly able to bypass obstacles that body and processes they put in their path. These advances also in the body, that stretch the tissue typically held in the home and surrounding tissues, organs can be responsible for compression. Meanwhile, they disseminate distance, by small foci distinct metastases.
Anatomical advancement of cancer should be evaluated by various complementary examinations (scanography, magnetic resonance imaging, scintigraphic). This assessment allows a classification of each cancer, associated with its histological features, allows a choice of treatment best suited
Treatment
Treatment is by surgery, radiotherapy (High energy X-rays, cobalt) chemotherapy (Administration of drugs having a damaging effect and immunology) and / or hormone (Taking hormones). Current research is focused on therapeutic method of cancer cells able to play normal characters . In this area, real successes have been achieved recently in some types of leukemia. Because of the difficulties of detecting and treating disease, cancer has great importance. Awareness seems a decisive factor. Certain gestures as breast self massage should be current. It should also be urged to comply with a certain life and the abolition of hygiene, to the extent possible, the risk behaviors..
Life with cancer
Increasingly patients are living many years with a cancer that can not be eradicated, but whose evolution is stopped or at least, brake enough to be removed any danger in the medium term. This stabilization still incurable disease is often the first step towards future cures. It creates new relationships which patients and physicians learn to perform, so it greatly modify behavior, making them the first to be more confident, and others prove more transparency. This new situation generates new problems for health, integrated in daily life of patients.
Thus, in case of infection, which are often more common in patients with impaired immunity from treatments or disease, patients must be vaccinated prophylactically with appropriate vaccines to be treated when the infection is installed. Feeding patients should not be neglected: they must take their vitamins necessary form of cruel, especially to eat ocean fish, whose lipids have a preventive effect on cancer and even on their expansion. Appetite, often small, can be restored, possibly by taking steroids or anabolic. Physical effort they are not generally contraindicated on the contrary, the patient should lead a normal life as possible.
In terms of physical state that deserves the greatest attention from doctors who prescribe drugs against anxiety, provided contra compliance. Pain if there may always be calm. Doctors sometimes underestimate them, the patient must deal with them and treat them. Finally, the subject as a bearer of cancer to have recourse, whenever desired, and a second piece of advice on proposed or ongoing treatment. Physicians must comply with this request, showing a spirit of cooperation legitimate. |
