Title {1}	TANGO - Effect of Tango Argentino on cancer-associated fatigue in breast cancer patients: Study Protocol for a Randomized Controlled Trial
Trial registration {2a and 2b}.	Trial registration number DRKS00021601. Retrospectively registered on 21 August 2020.
Protocol version {3}	The current protocol version is version 2.0, dated from 23 March 2020.
Funding {4}	The primary sponsor is the Forschungsinstitut Havelhöhe (FIH) gGmbH am Gemeinschaftskrankenhaus Havelhöhe.
Author details {5a}	SLO, MH, FS, AT: Research Institute Havelhöhe gGmbH at Hospital Gemeinschaftskrankenhaus Havelhöhe, Berlin, Germany; TR, HM, AT: Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Social Medicine, Epidemiology and Health Economics, Berlin, Germany; SB, JG: Hospital Gemeinschaftskrankenhaus Havelhöhe Breast Cancer Centre, Berlin, Germany; MH: Medical Clinic for Gastroenterology, Infectiology and Rheumatology CBF, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, MH, FS: Hospital Gemeinschaftskrankenhaus Havelhöhe, Interdisciplinary Oncology and Palliative Care, Berlin
Name and contact information for the trial sponsor {5b}	Research Institute Havelhöhe gGmbH at Hospital Gemeinschaftskrankenhaus Havelhöhe, Berlin, Germany Trial’s principal investigator: Friedemann Schad, fschad@havelhoehe.de; scientific coordinator: Anja Thronicke, anja.thronicke@havelhoehe.de
Role of sponsor {5c}	The sponsor is non-commercial. The sponsor ensures quality management, qualified and trained personnel, study protocol compliance, submission of relevant study documents to the ethics committee and regulatory authorities. He supports the study with trial unit facilities and study nurses.