Breast cancer
Breast Cancer: Definition, Causes, Prevalence & Risk Factors
What is breast cancer?
Breast cancer (medically: mammary carcinoma) is the most common tumour in women. In rare cases, the disease also occurs in men. Breast cancer is a very serious condition, but thanks to early detection and treatment, many patients are curable today – often even with gentle methods.
Therapy is tailored individually based on the extent of the disease and the patient's condition. Available treatments, which are often combined, include surgery, specific medication, and radiotherapy.
Recently, so-called "targeted therapies" have been added; these are treatments that precisely attack cancer cells (such as monoclonal antibodies).
How common is breast cancer?
Breast cancer is the most frequent cancer in women in Germany, accounting for approximately 28% of all new cancer cases among females.
The risk of breast cancer increases with age: younger women are rarely affected; it is only from the age of 40, and especially from 50 onwards, that the majority of women become ill. Most patients develop the disease after the menopause.
What are the causes and risk factors of breast cancer?
The exact causes of breast cancer are still largely unknown. However, certain risk factors are recognised – these are influences that promote the onset of breast cancer. How these factors influence each other, as well as their interaction with other factors such as age, has not yet been studied in detail. It should also be noted that some factors can be influenced, while others cannot. The main risk factors are as follows:
Women who are overweight develop breast cancer more frequently than women of a healthy weight. Excess body weight appears to increase the risk primarily after the menopause. People who consume high amounts of animal fats also seem to have a tendency towards a higher risk. The influence of other dietary habits remains uncertain, particularly the question of whether fruit and vegetables have a protective effect or what the effect of natural phytoestrogens (plant hormones found in food) might be.
In contrast, it is proven that alcohol increases the risk of breast cancer. The higher the alcohol consumption, the greater the risk.
Smoking appears to increase the risk. However, smoking across all age groups increases not only the risk of breast cancer but, more significantly, the risk of lung cancer.
Sex hormones such as oestrogen and progesterone can influence the risk of breast cancer. Taking the pill for many years can, for example, slightly increase the risk. At the same time, this form of hormonal contraception statistically offers slightly higher protection against other types of cancer, such as ovarian cancer.
Continuous hormone replacement therapy (HRT) used for years during the menopause (postmenopausal oestrogen therapy) causes the risk of breast cancer to rise. If the hormones are discontinued, the risk returns to the average level within a few years.
A late growth spurt in adolescence and a late onset of the menopause (climacteric followed by the menopause) also increase the risk.
Furthermore, women who have not had children or those who were over 30 at the birth of their first child present a higher risk. Every pregnancy or birth has a protective effect. Breastfeeding also has a protective effect, which increases the longer the breastfeeding continues.
In about 10% of all breast cancer cases, genes play a vital role: an initial clue (though by no means sufficient on its own) of a genetically increased risk may be a cluster of breast and ovarian cancer cases within the family.
What are NOT risk factors for breast cancer?
The media regularly cite alleged risk factors for which NO scientific link to this disease has actually been proven. These include:
- Wearing bras
- Vitamin D deficiency
- Lack of exposure to sunlight
- Infections
- Breast implants
- Terminations of pregnancy
- Deodorants containing aluminium. Regarding this, please also read our advice text: "Can aluminium deodorants make you ill?"
However, research has not yet identified all risk factors for breast cancer.