The study was aimed to evaluate the impact of perioperative nutritional support with high-protein mixtures on the risk of postoperative complications, postoperative recovery of respiratory functions in patients with lung cancer, nutritional status and quality of life of patients. Possible adverse events were also studied and described.

The study enrolled 114 patients with primary non-small cell lung cancer and nutritional deficiencies or at risk of developing them, admitted for surgical treatment and meeting other inclusion/exclusion criteria. Patients were randomly divided into two groups: the study group of 57 people and the control group of 57 people.

Patients in the study group, in addition to the usual diet, received nutritional support. During the hospital stay, additional nutritional support was added to the patient's standard hospital diet. On an outpatient basis, patients received the required amount at their disposal and will take it as a supplement to his usual and habitual diet.

Patients in the control group followed the standard hospital diet, and at discharge - the usual habitual diet.

The study was conducted using Enrollme.ru electronic platform. In total, the study comprised screening and 5 visits.

Inclusion Criteria:

• Presence of morphological verification of non-small cell lung cancer (NSCLC) without distant metastases;
• Appointment of surgical treatment for primary lung cancer with anatomical resection of the lung (lobectomy, bilobectomy or pneumonectomy);
• Nutritional deficiency or risk of its development (≥3 points on the Nutrition Risk Screening 2002 (NRS-2002) scale);
• No history of nutritional support;
• ECOG (Eastern Cooperative Oncology Group Performance Status Scale) score 0 - 2;
• Life expectancy over 3 months;
• Absence of serious diseases of the gastrointestinal tract, disorders of the liver, kidneys, systemic blood diseases and metabolic disorders at the time of inclusion in the study;
• Absence of severe uncontrolled concomitant chronic diseases and acute diseases (including infectious ones);
• Availability of signed informed consent for inclusion in the study and processing of personal data

Exclusion Criteria:

• Terminal state of the patient, ECOG (Eastern Cooperative Oncology Group Performance Status Scale) 3-4;
• State of refractory cachexia;
• Bleeding, serious injury or blood transfusions in the previous 6 months;
• Decay / abscess in the area of the tumor lesion;
• Presence at the same time of a tumor process of another localization, metastatic lesion of the lungs;
• The presence of concomitant diseases in the stage of decompensation;
• Pregnancy or lactation;
• Allergy to or intolerance to any of the components of Nutridrink Compact Protein, galactosemia, allergy to cow's milk proteins;
• The presence of contraindications to the use of enteral nutrition
• Participation in another study currently or in the past 30 days;
• Any other medical or non-medical reason that, in the physician's opinion, may prevent the patient from participating in the study

Primary lung cancer patients were enrolled in the study with or at risk of nutritional malnutrition admitted for surgery and meeting the inclusion/non-inclusion