RIBANNA Study

Breast cancer (mammary carcinoma) is a malignant disease of the breast glandular tissue characterized by the uncontrolled proliferation of breast gland cells. Treatment of the disease depends on numerous factors, such as the patient’s overall health, the stage of the disease, the tumor growth rate (Ki-67 index), the presence of detectable hormone receptors on the surface of the cancer cells (estrogen receptor-positive, progesterone receptor-positive), and the increased expression of the HER2 protein on the cells (HER2-positive). For advanced (stages 2B–3B) or metastatic (stage 4) hormone receptor-positive, HER2-negative breast cancer, hormone therapy is recommended as the standard of care. Typically, tamoxifen is used before menopause, and after menopause, an aromatase inhibitor is used either as monotherapy or in combination with, for example, ribociclib. This is an already approved CDK inhibitor designed to stop tumor growth. Another treatment option is chemotherapy.

The objectives of this observational study are to collect and analyze treatment data regarding the combination therapy of ribociclib plus an aromatase inhibitor, hormone therapy (letrozole, anastrozole, fulvestrant), and chemotherapy in routine clinical care. As part of the observational study, the researchers will examine, among other things, the efficacy of the therapy, the occurrence of side effects from the various medications, and the progression-free survival rate. Participation in the study does not entail any additional treatments, and the actual therapy is selected by the treating physicians.

Patients aged 18 years or older with hormone receptor-positive, HER2-negative, advanced or metastatic breast cancer (stages 2B–4) are eligible to participate in this study. The disease must not have been previously treated with systemic therapy in the advanced stage.