Observational Study on Tolerability, Side Effects, and Efficacy of Palbociclib Combined with Anti-Hormonal Therapy in Advanced Breast Cancer

Breast cancer (mammary carcinoma) is a malignant disease of the breast gland 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’s growth rate (Ki-67 index), the presence of detectable hormone receptors (HR) on the surface of the cancer cells (estrogen receptor-positive, progesterone receptor-positive), and the increased presence of HER2 receptors on the cells (HER2-positive). Cancer cells often have hormone receptors, making anti-hormone therapy a core element of treatment. In early-stage breast cancer, the goal is a cure, which is possible in a very large number of cases. If the cancer is advanced or has already spread throughout the body (metastasized), the goal of treatment is to “keep the disease at bay” for as long as possible. As a result, patients are increasingly able to live for many years with a good quality of life. In postmenopausal patients with advanced disease, anti-hormone therapy is considered the standard of care following surgery. For some time now, this has been combined, whenever possible, with a CDK4/6 inhibitor, as this can enhance the effect of anti-hormone therapy. Palbociclib is an already approved CDK4/6 inhibitor. Nevertheless, further data on the efficacy and safety of this therapy are to be collected.

The goal of the PERFORM study is to further investigate palbociclib in combination with anti-hormonal therapy. Over a period of up to 7.5 years, the study will monitor, among other things, disease progression, patients’ quality of life, and the point at which further treatment, such as chemotherapy, becomes necessary. The exact treatment regimen is not specified in this study. Patients should not have previously received therapy for advanced disease and must receive a combination of palbociclib and anti-hormone therapy as first-line treatment. The exact combination of medications depends on the stage of the disease, the treatment goal, and the patient’s individual health status, as well as whether female patients are already postmenopausal. No new medications or therapies are being tested.

Eligible participants include women and men aged 18 and older with hormone receptor-positive, HER2-negative breast cancer at the locally advanced or metastatic stage. Patients must not have previously received systemic treatment for advanced breast cancer and must receive combination therapy with palbociclib as their first line of treatment.