The specific cause is unknown. There are however some factors if associated with making a woman stand a higher risk of developing breast cancer:
Getting older puts one at a higher risk of contracting all types of cancers. This is because of degraded Antibody that would fight even the slightest infection. It becomes more worse to immuno compromised individuals.
2. Family history of breast cancer.
The cancer causing genes might be inherited either from the parents as a dominant or recessive genes. This will later affect the individual as he/she grows. Some are born right with the cancer.
3. Intake of high estrogen pills over a long time.
Estrogen is a female endocrine hormone. It has a role in female reproduction and that includes breast development, milk production etc. Too much of this intake alters the own body estrogen. This affects the breasts!
4. High Fat Diet.
Lot of fat may trigger any form of cancer. This fats are loaded with cholesterol. Intake of excess cholesterol is actually carceinogenic
5. Being overweight and obese.
There are high chances that these individuals have high blood pressure and probably diabetes mellitus.
Some forms of recurrent breast lumps need to be monitored regularly.
Not having any of the above risk factors does not mean that one is immune to breast cancer. Conversely, having any of these risk factors will not necessarily lead to the development of breast cancer