The MARIE Study

MARIE is a large population-based case-controls study conducted between 2002 and 2005 to identify potential risk factors for the development of breast cancer after menopause. "MARIE" is an acronym for Mammary carcinoma risik factor Investigation. Almost all incident patients from the Rhine-Neckar-Karlsruhe and Hamburg regions aged between 50 and 74 years were interviewed personally. As a comparison group, women of the same age without breast cancer from the same cities and counties were randomly selected and interviewed in-person in order to compare them with the patients. All participants were also asked to provide a blood sample for molecular and genetic investigations.

The main objective of MARIE was to identify modifiable risk factors for the development of postmenopausal breast cancer and thus to find approaches to reduce the risk of breast cancer. To do this, we examined the influence of the following factors:

• Menopausal hormone therapy
• Factors related to pregnancy, childbirth and menstruation
• Lifestyle habits such as physical activity, diet, smoking and alcohol consumption
• Pre-existing illness
• Genetic variants

• Full-term pregnancies protect against breast cancer. Especially, if they occur at a younger age.
• Breastfeeding is also a protective factor.
• Taking hormones to relieve menopausal symptoms increases the risk of developing breast cancer. This is particularly true with continuous estrogen-progesterone combination therapy. If used for more than 5 years, the risk of breast cancer is almost twice as high as that of women who are not taking hormones.
• The MARIE Study confirms physical activity as a protective factor.
• There was no increased risk of breast cancer in relation to smoking and passive smoking.

A more detailed description of the results can be found in the study report, and further details are available in the scientific publications.