Malnutrition occurs frequently in patients with cancer during and after radiotherapy to the gastrointestinal (GI) area and can lead to negative outcomes. N-3 fatty acids from fish, especially eicosapentaenoic acid (EPA) may possess anticachectic properties. The aim of this study is to investigate the effect of two nutritional interventions; dietary counselling and an oral nutritional supplement (ONS) containing 2.2 g of the n-3 fatty acid EPA (Forticare®) or standard care, including dietary counselling and protein supplementation when needed.

Methods: Outpatients commencing radiotherapy to the GI area due to dissiminated cancer are randomized to receive dietary counselling and daily fish-oil supplementation over a 5-7 week period, or standard care. Outcome parameters are measured at baseline (onset of radiotherapy), week 5, and 12 weeks after commencing radiotherapy, with one additional measurement of body weight at week 2. Quality of life (QoL) is measured using the EORTC QLQ-C30 questionnaire. Radiotherapy-related side effects are assessed using a questionnaire developed specifically for this study. Data from a historical control group collected in a previous observational study is included in this study to compare incidence of weight loss.

Inclusion Criteria:

• referred to radiotherapy for dissminated, abdominal cancer
• > 18 years of age
• able to understand and comply with the intervention
• willingness to participate after oral and written conscent

Exclusion Criteria:

• conditions precluding evaluations of end-points
• dementia
• operations planned in the observation period