The aim of the study is to analyze the implementation of the 2018 updated ESMO Guideline in patients with tumor diseases as well as the corre-sponding recommendations of the Onkopedia Guideline and the S3 Guide-line Supportive Therapy in routine clinical practice in Germany.

To this end, a nationwide, representative, retrospective patient documen-tation will be conducted to observe the current practice of anemia man-agement in hospitals and among office-based physicians.

Health care structure analysis and recruitment (phase 1):

In a first step, data on care facilities treating patients in the above indica-tions in Germany will be collected (gastroenterology, gynecology, hema-tology/oncology, and pneumology hospital departments, as well as of-fice-based hematologists/oncologists and gynecology oncologists).

In Phase 1, all centers in Germany potentially treating patients in the above entities will be contacted and data on the care level of the institu-tion and the number of patients treated will be collected using a one-page pen-to-paper form. In addition, the willingness of the care facilities to participate in the documentation of patients will be surveyed (Phase 2).

Analysis of patient records (phase 2)

In order to obtain a reliable, representative sample of patients treated in Germany, the distribution of the cases to be documented in the individual indications among the participating facilities is determined. For this pur-pose, the data collected from the facilities in Phase I on patient numbers and treatment structure will be used:

Participating centers are divided into clusters based on key distinguishing characteristics (facility type, level of care, and number of patients treat-ed). This sample is modulated according to the previous care structure analysis. This approach allows the actual percentages of the different care facilities in an indication area to be proportionally included in the patient documentation sample.

In Phase 2, a multi-page electronic case record form (eCRF) will be com-pleted to collect patient and treatment data relevant to the purpose of the study. All data will be collected retrospectively and anonymously from patient records.

• Patient- and disease-related variables (age, ECOG performance status, staging, relevant comorbidities).
• Drug therapy (chemotherapy, antibodies, immunotherapy, kinase inhibitors: Start/end, substances or regimens).
• Radiotherapy (start/end, irradiated region)
• Laboratory diagnostics (if available) with Hb, Hk, MCV, MCH, re-ticulocytes and/or Ret-Hb, ferritin, transferrin and/or transferrin saturation (TSAT), holo-trans-cobalamin (vitamin B12), folic acid, zinc protoporphyrin, creatinine clearance (GFR), EPO level
• Data on anemia therapy (transfusion of RBC; iron therapy p.o. or i.v.; ESA). To ensure data quality, the scientific project lead will train two employees of the commissioned institute in content-related issues of the study. This knowledge will be incorporated into the programming of the user inter-face and the patient databases so that the program will check for com-pleteness and, as far as possible, plausibility based on defined require-ments and framework conditions. These checks accompany the process of data entry into the eCRF and enable immediate validation of the data.

Inclusion Criteria:

Patients

• with antineoplastic therapy (chemotherapy or "new substances"), radiochemotherapy or radiotherapy in the period 1/1/2021 - 06/30/2021
• with anemia with hemoglobin levels decreases below 10g/dl (6.2 mmol/l) at least once during the period 1/1/2021 - 06/30/2021
• with at least 4 weeks of follow up period after anemia diagnosis.

Exclusion Criteria:

• Follow up time less than 4 weeks,
• lack of patient contact after anemia diagnosis

Patients with solid tumors or malignant lymphoma

Data is collected retrospectively and completely anonymously from patient records, no identifying characteris-tics (e.g. birth date, initial letters, pseudonym) will be collected.

It is hoped that these data will assist in creating new possibilities and ways to improve the quality of treatment through further training and enhancement of the availability and transparency of the guidelines.