It is still unclear how exactly breast cancer or breast cancer develops. However, risk factors for breast cancer are known that can contribute to cancer growth. Many of these breast cancer promoting factors are clearly associated with the female sex hormones. These include early onset of menstruation, childlessness or old age at the first pregnancy (over 30 years) and the late onset of menopause. Conversely, multiple births or births at younger ages, as well as longer breastfeeding periods are considered factors that reduce the risk of breast cancer.
Risk factors and causes of breast cancer
However, ovulation inhibitors such as the pill and hormone replacement therapy (HRT) with estrogens and progesterone during menopause should increase the risk of breast cancer. After discontinuation of the hormones, however, the risk of breast cancer should decline again. However, whether the hormones trigger a tumor or that an already existing tumor only grows faster due to the hormone intake is still controversial.
In addition, a pronounced masthopathy (change in the mammary gland) with cysts and nodules in the breast tissue can promote the development of breast cancer (breast cancer). Other unfavorable factors for breast cancer, which can also be causes, are obesity and physical inactivity, smoking and larger or regular amounts of alcohol. For example, the daily consumption of ten grams of alcohol already increases the risk of breast cancer by ten percent.
In addition, age may also play a role in the development of breast cancer: women over the age of 50 have a significantly higher risk of developing breast cancer as they become more likely to have cell division defects. On the other hand, according to the current state of research, nutrition seems to have no influence on the development of breast cancer.
Influence of genes
Certainly, the genetic influence on the development of breast cancer: Are in the close relationship (especially in the mother or sister) diseases occurred, the risk of developing breast cancer, about two to three times as high as a woman without a diseased close relatives. This is true even if the previously known "breast cancer genes" (BRCA, BARD, AKAP) are not detected.
If a woman already has breast cancer on one breast, the risk of developing the other breast increases. The extent to which the risk increases exactly depends, among other things, on the location and type of the tumor and the type of treatment.