[Weight loss in cancer patients].

Cancer patients are regularly affected by malnutrition which often leads to a worsened quality of life and activity in daily living, more side effects and complications during anticancer treatment and shorter survival times. The early diagnosis and treatment of malnutrition are therefore relevant components of oncological treatment. The assessment of the nutritional status and determination of the body-mass-index should be done in every patient with cancer. The clinical examination delivers important findings and indications for malnutrition. Bioimpedance analysis can deliver additional objective information. The treatment of malnutrition should start early and follows a step-wise escalation reaching from nutritional counseling to enteral nutritional support to parenteral nutrition.