Impossibility to accomplish the sample size in assigned time.

The purpose of this study is to determine if a nutritional supplement enriched in omega-3 fatty acids is effective in improving the tolerance to chemotherapy treatment and improves quality of life.

Colorectal cancer is one of the main causes of mortality in western countries. It is considered that in case of colorectal carcinoma, the frequency of weight loss at the moment of diagnosis is 54%. Undernourishment affects negatively the course of the illness and it confers a worse prognostic, increasing the morbidity and the mortality, while it entails an impairment in the quality of life of the patient.

There is a narrow relationship in the oncologic pathology between undernourishment and the pathology itself, drawing a common syndrome called cancerous cachexia. It is usual that patients subjected to chemotherapy present nutritional alterations due to the treatments' side effects.

With this study we want to assess the efficacy of a nutritional intervention with supplementation enriched in EPA to improve the tolerance to the antineoplastic treatment. As an index of tolerability to the chemotherapy treatment, it will be used the variation of changes in quality of life evaluated through the questionnaire EORTC QLQ-C30, using the parameters of global quality of life and physical function.

Inclusion Criteria:

• Patients diagnosed of metastatic colon adenocarcinoma that are going to receive first line chemotherapy treatment in the oncology day hospital.
• Age over 18 years old.

Exclusion Criteria:

• Patients diagnosed of colon cancer are receiving second line chemotherapy.
• Antecedents of other malignant tumors with the exception of basocellular epithelioma.
• Chronic renal failure (Creatinine > 1.7).
• Previous diabetes mellitus.
• Obesity (IMC > 30)
• Medical conditions that imply hepatic encephalopathy, or ascites.
• Severe malnutrition according to the classification of the Subjective Global Assessment (SGA) or a BMI < 16.5.
• Major psychiatric disorder.
• Patients receiving enteral or parenteral nutrition.
• Contraindications for the indication of the nutritional supplement: Galactosemia.
• Seafood or seafood byproducts allergy.
• Patients taking drugs that affect the metabolism (anabolic steroids, orexigenic agents...).
• Absence of the informed consent form signed by the patient.
• Any patient who has disability to comply with the treatment or who has inability according to the researcher.