Cancer is the name given to a set of more than 100 diseases that have in common the disordered ( malignant ) growth of cells that invade the tissues and organs and can spread ( metastasize ) to other regions of the body.
Dividing rapidly, these cells tend to be very aggressive and uncontrollable, determining the formation of tumors (accumulation of cancer cells) or malignant neoplasms. On the other hand, a benign tumor simply means a localized mass of cells that multiply slowly and resemble their original tissue, rarely constituting a risk to life.
Different types of cancer correspond to the various types of cells in the body. For example, there are several types of skin cancer because the skin is made up of more than one type of cell. If the cancer starts in epithelial tissues such as skin or mucous membranes it is called carcinoma. Whether it begins in connective tissues like bone, muscle or cartilage is called sarcoma.
Other characteristics that differentiate the different types of cancer among themselves are the speed of multiplication of the cells and the ability to invade neighboring or distant tissues and organs ( metastases ).
What causes cancer? The causes of cancer are varied, being external or internal to the organism, both being interrelated. External causes are related to the environment and to the habits or customs proper to a social and cultural environment. Internal causes are, for the most part, genetically predetermined, linked to the body’s ability to defend itself against external aggressions. These causative factors can interact in various ways, increasing the likelihood of malignant transformation in normal cells.
Of all cases, 80% to 90% of cancers are associated with environmental factors. Some of them are well known: cigarette smoking can cause lung cancer, excessive exposure to the sun can cause skin cancer, and some viruses can cause leukemia. Others are under study, as are some components of the food we eat, and many are still completely unknown.
Aging brings changes in cells that increase their susceptibility to malignant transformation. This, coupled with the fact that older people’s cells have been exposed to different risk factors for cancer, explains in part why cancer is more frequent in these individuals. The environmental risk factors for cancer are called carcinogens or carcinogens. These factors act by altering the genetic structure (DNA) of cells.
The onset of cancer depends on the intensity and duration of exposure of the cells to cancer-causing agents. For example, a person’s risk of developing lung cancer is directly proportional to the number of cigarettes smoked per day and the number of years they have been smoking. source: articlesonhealth.net
Risk factors of an environmental nature
Cancer risk factors can be found in the environment or can be inherited. Most cases of cancer (80%) are related to the environment, in which we find a large number of risk factors. The environment is understood as the environment in general (water, earth , nd air), the occupational environment (chemical and related industries), the environment of consumption (food, medicine), the social and cultural environment (style and habits of life).
The changes brought about by the man himself, the ‘habits’ and the ‘lifestyle’ adopted by the people, can determine different types of cancer.