LEGO is single center double-blind randomized trial aimed at testing the efficacy of an essential ammino acid (EAA) supplementation in improving the absolute count of peripheral lymphocytes and the tolerance to chemotherapy in patients with advanced gastrointestinal malignancies not candidates to immune check-point inhibitors containing regimens.

The aim of the study is to verify that, in lymphopenic patients, AAE supplementation leads to an increase in lymphocytes circulating in the blood. In particular, at the end of treatment, in patients with lymphocytes < 29.7% of the total number of white blood cells, we want to observe the disappearance of lymphopenia.

Inclusion Criteria:

• diagnosis of epithelial neoplasia of the gastrointestinal tract in advanced stage with indication for first-line chemotherapy for palliative purposes and with circulating lymphocytes < 29.7% of the number total white blood cells in the blood.
• ECOG PS ≤ 2
• start of first-line palliative chemotherapy agreement with AIOM guidelines.
• adequate nutritional counseling carried out before starting of the treatment
• willing to participate by providing written informed consent

Exclusion Criteria:

• age < 18 years
• current or indicated artificial nutrition
• gluten intolerance
• prediction of use of granulocyte growth factors
• confirmed diagnosis of COPD, chronic heart failure, insufficiency chronic kidney disease, chronic liver failure, collagen disease, diseases endocrine, insulin-dependent diabetes, malignancy in other locations. All these conditions are associated with documented alterations in the plasma profile of amino acids and potentially of subsets of circulating T lymphocytes.