Treatment Pathways and Clinical Characteristics Among Patients with Metastatic Breast Cancer in Germany: A Retrospective Descriptive Analysis with Data from 2020 to 2023

Abstract

Breast cancer is the most common cancer among women worldwide and represents a significant health challenge. It is caused by uncontrolled growth of breast tissue cells and can metastasize to other parts of the body if it is not detected and treated in time. Breast cancer treatment is tailored to the individual and depends on various factors, including type and stage of the tumor, hormone receptor status, and the patient's overall health. For patients with metastatic breast cancer (mBC) the primary treatment modalities include systemic drug therapies such as hormone therapy, chemotherapy, targeted drugs, and immunotherapy. These treatments aim to reduce the tumor size, alleviate symptoms, and prolong survival.

This study will address the gap in our understanding of the real-world treatment patterns and outcomes of mBC in Germany.

The objectives of this study are: • Conduct a descriptive analysis of incident mBC patients, focusing on their demographic and clinical characteristics. • Examine the HER2 status distribution and its impact on treatment decisions. • Classify breast cancer cases according to ICD-10 and ICD-O. • Describe treatment patterns of all incident mBC patients. • Analyze overall survival, progression-free survival, and response rate of mBC patients.

This retrospective study will utilize data from the German Centre for Cancer Registry Data (Zentrum für Krebsregisterdaten, ZfKD) at the Robert Koch Institute (RKI), covering diagnosis years 2020 to 2023. Patients with newly diagnosed mBC within this period will be included. Exclusion criteria will involve incomplete records and non-metastatic cases. Statistical analysis will be conducted using appropriate methods and software to examine treatment outcomes and trends over time, such as descriptive statistics and Kaplan-Meier for overall survival. The choice of statistical techniques will be further specified based on the data availability.

The study aims to provide valuable information for patients and various stakeholders involved in mBC management. This will be achieved by improving the understanding of the treatment pathways as well as demographic and clinical characteristics of mBC patients in Germany.