Galenos 2 Immunonutrition in Head and Neck, Lung, and Rectal Cancer Patients

Inclusion Criteria: * Written informed consent to study procedures * Male or female, age greater than 18 years * Histological or cytological documentation of head and neck squamous cell carcinoma, locally advanced rectal cancer, or lung cancer candidate for immunotherapy, chemotherapy, and/or radiotherapy according to standard clinical practice * ECOG Performance Status score less than 2 * Adequate kidney, liver, and bone marrow function * Ability to understand, sign informed consent, and comply with study procedures Exclusion Criteria: * Incomplete recovery from surgery before starting antineoplastic treatment * Other progressing malignancy or malignancy requiring active treatment within the last 3 years, except localized basal cell carcinoma, localized squamous cell carcinoma of the skin, or cervical carcinoma in situ * Active infection requiring systemic antibiotic therapy * Serious or unstable medical conditions, psychiatric disorders, or substance abuse interfering with study compliance * Receipt of any live vaccine within 30 days before study treatment * Active cardiac pacing/pacing implants/neurostimulators/hearing system not compatible with bioimpedance analysis * Edema and/or ascites not compatible with body weight evaluation and bioimpedance analysis * Enteral or parenteral nutritional support at baseline