The MARIEplus study is a prospective cohort of breast cancer patients recruited into the MARIE (Mamma Carcinoma Risk factor InvEstigation) study, a population-based case-control study of breast cancer conducted in two German study regions, Hansestadt Hamburg and Rhine-Neckar-Karlsruhe (RNK) region. Participants were identified through participating clinics and the Hamburg cancer registry between January 1st, 2001 and September 30th, 2005 in Hamburg and between August 1st, 2002 and July 31st, 2005 in the RNK study region. Patients were aged 50-74 years at histologically confirmed primary invasive (stages I to IV) or in situ breast tumor (stage 0). Comprehensive information on demographic, socio-economic, and lifestyle factors was collected at multiple time points: at recruitment by a standardized face-to-face interview and at follow-up median 6 years as well as 11 years later using computer assisted telephone interview.

Vital status was assessed in 2009 and again in 2015 via the population registries and causes of death were obtained from death certificates and coded according to the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10).

Information on the clinical course was abstracted from medical records to verify clinical events either self-reported in follow-up interviews or reported by treating physicians.

The studies were approved by the ethics committee of the University of Heidelberg and the University of Hamburg and conducted in agreement with the Helsinki Declaration. Written informed consent was provided by all participants at baseline and during follow-up.

The primary objectives of this study are

• To assess the association of modifiable lifestyle factors and personal factors, including BMI, diet, physical activity, tobacco and alcohol use, menopausal hormone therapy, socioeconomic status, with breast cancer survival, overall and according to tumor type, after accounting for established prognostic factors.
• To examine the influence of genetic variants on breast cancer relapse and survival
• To assess the association of lifestyle factors and their changes in the course of survivorship on subsequent breast cancer prognosis.
• To assess the individual and combined association of inflammation/metabolic biomarkers as well as changes in their serum levels with subsequent breast cancer prognosis overall and according to tumor type.
• To assess whether and to what extent the associations between breast cancer prognosis and lifestyle factors and/or their changes are mediated by circulating biomarker levels.

Inclusion Criteria:

• Histologically confirmed Primary invasive (ICD-10 C50) (stage I-IV) or in-situ (ICD-10 D05) breast cancer
• 50 to 74 years at diagnosis
• Patients in the city and state of Hamburg in northern Germany and the Rhine-Neckar-Karlsruhe region in southern Germany
• German-speaking
• Physically and mentally ability to participate in a personal interview of about 90 minutes

Exclusion Criteria:

• Previous diagnosis of breast cancer

Patients with histologically confirmed primary invasive or in situ breast tumors aged 50-74 years at diagnosis recruited in the city and state of Hamburg or the Rhine-Neckar-Karlsruhe region