Cancer

Cancer is presented by a class of illnesses, where cells act aggressively (grow and are divided outside the normal characteristics), metastatic (relocated to other destinations in the organism) and invasive (able to intrude and ruin nearby tissues). These negative features of cancer make it different from positive neoplasm, which is self-confined in the process of growing and are not invasive or metastatic (however, some positive neoplasms are able to transform to negative). People of every age are exposed to cancer, even fetuses, but commonly the possibility to receive it enhances with age. Cancer is the reason of over 13% of the entire amount of deathly cases. Cancer is capable to invade not only humans, but animals and plants. Practically all cases of cancer are the result of abnormalities, appeared in the transformed cells' genetic material. Such abnormalities can be the reason of the effect of carcinogens, for example radiation, chemicals, tobacco smokes, or infectious substances. Cancer is commonly categorized in respect to the tissue, in which its origin lies, and also the traditional cell category they are mostly similar to. Cancer is rather difficult to cure and requires several methods as well as chemotherapy, but there exist also some medicines, as Nolvadex, used in treatment.