After menopause

Most common breast cancer often caused by obesity

Weight data, fat measurements and questionnaire information on the social situation, family status and lifestyle such as diet, alcohol consumption etc. were used for the long-term study.

(Bild: stock.adobe.com/Zaiets Roman)

The most common form of breast cancer, hormone-dependent breast cancer, is thought to be particularly often associated with obesity in post-menopausal women. 40 percent of cases can be attributed to this.

Naiara Cubelos-Fernandez from the Institute of Biomedicine at the University of Leon in Spain and her co-authors from numerous other Spanish research institutions recently published their study in the Journal of Epidemiology & Community Health.

In a long-term study in over a dozen Spanish provinces, they investigated how body weight and body fat percentage are associated with breast cancer (mammary carcinoma). Data on weight, fat percentage and questionnaire information on social situation, family status and lifestyle, such as diet and alcohol consumption, were analyzed.

Finally, the data from 1033 test subjects with breast cancer was compared with information from 1143 women without breast cancer. According to the results, the risk of breast cancer in post-menopausal women increases with every extra kilo.

Overweight women were 52 percent more likely to develop postmenopausal breast cancer. With grade I obesity (BMI greater than 30), the risk increased by 68 percent.

Deutsches Ärzteblatt

Taking the body mass index into account, the curve flattened for higher-grade obesity (BMI greater than 40), but this is probably an artifact of the calculation.

Production of oestrogen stops with menopause
The connection between body fat and hormone-dependent breast cancer after the menopause is probably mainly due to the following fact: the production of oestrogen in the ovaries stops with the menopause. The fat cells remain as a production site for oestrogen. More body fat therefore means more of the body's own oestrogen.

In Austria, around 5600 women are diagnosed with breast cancer every year. Around 1600 patients succumb to such a tumor disease every year.