What is cancer?
Cancer is an illness that consists of anarchical cellular proliferation. When someone suffers from cancer, a part of his or her cells multiply uncontrollably and uninterrupted. In Europe and North America, the most common types of cancer are lung cancer, tightly related to smoking, and breast cancer, for which causes have not been thoroughly investigated yet. In Africa, the most common type of cancer is liver and cervical cancer.
What types of cancer do we know of?
Here are the types of cancer discovered throughout history (enumerated below). I will treat them in depth in individual articles. In order to find out about a type of cancer from below, you only need to click on its name. If the name does not yet link to another page, that means I am currently working on the respective article:
Oral cavity cancer (also known as mouth cancer);
Gastric cancer (also known as stomach cancer);
Causes of cancer
Cancer is caused by regular exposure to viruses, natural or chemical substances, or radiations. Our body responds to these inadequate exposures with inadequate mutations of a special kind of genes, called oncogenes. These genes are directly involved in proliferating cells and are regularly under the control of anti-oncogenes, which may die or suffer a mutation themselves under the circumstances mentioned above. It is worth mentioning that these anti-oncogenes may hereditary be missing in one’s body, which explains why certain families are prone to cancer.
At men, alcohol is a risk factor for mouth and liver cancer. The combined effect of alcohol and tobacco corresponds to a higher risk of having cancer (this is called multiplicative effect). A number of studies show that there is an increased risk of breast cancer for women that consume alcohol, rather than for women that do not.
Studies have shown that nutrition is related to the genesis of certain kinds of cancer. In this respect, the foodstuffs we must consider are the ones containing a large amount of fat, a large amount of fibres and vitamins and the ones containing Aflatoxin and Nitrite. Fats are supposed to cause cancer in what concerns colorectal, breast and prostate affections. Basically, the more fat you consume, the more likely you are to get these three types of cancer. It is worth mentioning that no effects of coffee on cancer have yet been proved. Nitrite, most commonly found in salt, is supposed to increase the risk of stomach cancer. Aflatoxin, on the other hand, is directly related to liver cancer. Most foodstuff deposited in warm and wet places have Aflatoxin.
A study conducted in 1944 showed that ten times more radiologists dies by leukemia than other medics. Before the survivors of the atomic bombing from Hiroshima and Nagasaki in 1945, the first cases of leukemia were officially observed in 1941. Leukemia cases reached their peak in the years 1951-1952. Abnormal cancer types have continued to show up 15 years later after the bombings and continue to manifest themselves today. Nowadays, radio-protection regulations have made professional risks diminish, particularly in the case of radiologists and workers within atomic installations. Additionally, progresses in radiology and medicine have diminished risks for patients who need to X-Ray part of their bodies.
Some rare diseases are accompanied by an increased risk of cancer, e.g. retinoblastoma and trisomy. This happens because the diseases favor tumours.
Drugs which provoke cancer
Attention on cancer-related drugs has increased lately, with the apparition of vaginal cancer to girls who were born from mothers that have received estrogen during the first three months of pregnancy. When estrogens are used as contraceptives, the risk of breast cancer increases. In this regard, using contraceptives is not recommended for a very long use, before a first pregnancy or if you have already had some medical breast complications. American studies have shown that the risk of having cervical cancer is from 4 to 8 times higher at a woman who have reached menopause and has used contraceptives throughout her life. Beside hormones, drugs which increase cancer probability are immunosuppressants and arsenic derivatives.
Some types of cancer may be facilitated by inherited predispositions. The family members relatives to a person affected by colorectal cancer are from 2 to 4 times more likely to have the same type of cancer than other persons. This mechanism is currently explained by gene-dependency, but most often only becomes noticeable when the environmental factors force it to manifest itself.
In the last few decades, tanning has often been related to skin tumors, carcinomas and melanomas. This is all due to the ultraviolet solar radiations, particularly to U.V.B. ones, which are the shortest-waved and most deadly ones. Skin cancer is most frequent to people with light skin colors.
In 1975, the relation between exposure to smoke and scrotum cancer has been made official. In 1985, an alarming number of bladder cancer has been signaled at workers in the dyestuff industry. The most recent research of The International Research Center has shown that, out of 707 industrial substances and procedures which were tested, 7 procedures and 23 substances have been proved to cause human cancer.
There has literally been a blast in lung cancer within the last 40 years. This has mainly to do with tobacco, which is responsible for approximately 90% of the lung cancers. The risk is proportional to the amount of tobacco smoked and the age one has when he or she begins to smoke. The filter has been proved to lower the risk of cancer, while black tobacco is known for its high cancer risk. Passive smokers and people living in smoky environments are also subject to a greater risk.
The roles of retroviruses are well-known at animals; at humans, however, out of all retroviruses, only H.I.V. (Aids) and H.T.L.V. (Leukemia) seem to bear cancer potential. Nevertheless, the human D.N.A. may also host some viruses that cause cancer.
The first connection between viruses and cancer was based on a basic Herpes virus (Epstein-Barr) and the African lymphoma Burkitt (in 1964). In 1978, the H.B.V. virus, which causes Hepatitis B was found to increase the risk of liver cancer. Not least, cervical cancer may relate to sexual-transmitted diseases (the sources 16, 18 and 33, belonging to the H.P.V. virus).
Symptoms and diagnostics
The multiplicity of cancers and their specific manifestations render the listing of all cancer symptoms impossible. However, a significant loss in weight and in food appetite, an intense fatigue, loss of blood when defecating or spitting, and other types of pain may be associated to the presence of cancer. Quite often, cancer evolves slowly, which means it is often diagnosed too late by doctors, who may only be sure it is cancer when it has reached an advanced stage of its evolution. From time to time, cancer is discovered by chance, by means of a random blood test. In all cases, cancer is diagnosed only after several clinical, laboratory, radiological and endoscopic examinations. Posthumously, cancer can be diagnosed by means of biopsy.
How does cancer evolve?
tags: Cancer, Causes