<p>Clinical oncological research forms an essential foundation for progress in cancer treatment. Sponsors and contract research organizations (CRO) make a substantial contribution to the planning, organization and performance of clinical studies, whereby the AIO-Studien gGmbH takes the responsibility in particular for studies initiated by principal investigators and oncological register projects. The General Data Protection Regulation (DSGVO) protects personal healthcare data and grants comprehensive rights to those affected but represents a challenge to the practical implementation in research. The appropriation of data usage and the complexity of informed consent, in particular, lead to uncertainty and make the use of secondary data for further questions more difficult. Furthermore, heterogeneous data protection requirements at the federal and institutional levels cause a substantial contractual fragmentation, which increases the time investment and expenditure. The international data traffic is additionally burdened by legal uncertainty, such as the “Schrems-II” verdict, which impairs cooperative research. Despite the important aims of data protection, the current regulations often result in a field of tension between data protection and scientific research, which inhibits progress. Standardized understandable information material, centralized data protection assessment, nationwide harmonization of contracts as well as technological and political measures for optimization of data protection in the research environment are recommended. A pragmatic dialogue between all parties is considered necessary to harmonize data protection and research efficiency.</p>