This is the study of the various factors that affect not only the health, but also the incidence of illness in a population. In the study of diseases that not only spread within a population, but also those that do not, the role of an epidemiologist ranges from investigation into outbreaks to study design, collect data and analysis. A further important role is the study of the interaction of diseases in a population.

The application of epidemiological risk factors for a particular disease can act as a pointer in terms of the etiology (which is the study of the origination or cause of a disease) of that disease.

The first case study, under controlled conditions, relating to breast cancer epidemiology was performed by Janet Lane-Claypon in 1926. She published a comparative study which consisted of 500 patients who had actually contracted breast cancer and a further 500 patients, without the disease, who were used as a control sample. Both groups of patients hailed from similar backgrounds and lifestyles.

Just like other forms of cancer, breast cancer is now regarded as having its roots in a combination of factors relating, in the main, to the environment and heredity. The following lists some of the more important contributors:

The incidence of lesions on the DNA (which is a nucleic acid that holds the genetic codes which are necessary in the development and ability to function of all known living organisms), as in the case of genetic mutations (which represent a random change to the sequence of the genetic material of an organism). The presence of estrogen has been shown to be linked to certain mutations that can ultimately lead to the development of breast cancer. Research has shown that other causes of genetic mutations include viral oncogenesis and the presence of ionizing radiation (exposure to radiation can cause damage to living tissue, which can result in cancer, tumours, and genetic damage when subjected to even low doses).

The failure of a system called immune surveillance. This is a theory that has been put forward in which the immune system is capable of removing malignant cells. It even goes further by proposing that such a capability is available throughout the entire life of an individual.

Another factor which encourages the growth of malignant cells is the incidence abnormal growth factor. Its presence is influential in affecting the interaction of stromal cells with epithelial cells. Growth Factor is a substance that occurs naturally, and is capable of activating not only the growth of cells, but also their proliferation and cellular differentiation (which is a process that frequently occurs during the development of a multicellular organism as it changes from a single entity into a complex system of tissues and cell types. Usually it is a protein or a steroid hormone).
Stromal cells refer to connective tissue cells that can be found in an organ. The interaction between stromal cells and tumour cells has been shown to be a major factor in cancer growth and propagation. The epithelium is a tissue composed of cells which coat the cavities and surfaces throughout the body. Consider the following example. Tumours are capable of facilitating the growth of blood vessels, a process called angiogenesis, by secreting a variety of growth factors which further encourage cancer growth.

A final factor involves inherited defects in DNA repair genes. DNA repair refers to a number of processes whereby a cell identifies damaged DNA molecules and then sets about making the necessary adjustments. In the case of human cells, either normal metabolic processes or factors associated with the environment, such as UV light or certain Radiations, are able to cause DNA damage. This process is ongoing as it seeks out and repairs damage to the DNA structure.

Breast Cancer – How To Succeed

Author's Bio: 

Peter Radford writes Articles with Websites on a wide range of subjects. Breast Cancer Articles cover Background, Symptoms, Risk, Prevention, Treatment.

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