SummaryGeriatric assessments, nutritional counseling and monitoring of muscle health before and during therapy are of high clinical significance in the management of elderly cancer patients. Criteria, data and cut-offs characterizing cancer-related geriatric sarcopenia are sparse and no consensus about definitions exists to date. We hence highlight a need for clinical trials focusing on sarcopenia in elderly cancer patients, based on its high prevalence and potential negative consequences on therapy outcomes, mortality, quality of life and physical mobility.