Omega-3 Supplementation and Immunotherapy in Gastric Cancer: A Phase II Trial

Inclusion criteria

• Age: Participants must be aged 18 years or older.
• Diagnosis: Confirmed diagnosis of locally advanced gastric or gastroesophageal junction adenocarcinoma, classified as clinical stage II or III according to the American Joint Committee on Cancer (AJCC) staging system.
• Performance Status: Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2, indicating that patients are fully active or restricted in physically strenuous activity but are capable of self-care.
• Histological Verification: Tissue confirmation of diagnosis must be obtained via biopsy, with adequate archival tumor tissue available for biomarker analysis if required.
• Organ Function: Adequate organ function as evidenced by laboratory tests:

Absolute neutrophil count (ANC) ≥ 1,500/mm³ Platelet count ≥ 100,000/mm³ Hemoglobin ≥ 9 g/dL Serum creatinine ≤ 1.5 times the upper limit of normal (ULN) Total bilirubin ≤ 1.5 times the ULN (unless due to Gilbert's syndrome) Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 times the ULN (≤ 5 times the ULN if liver metastases are present)

• Informed Consent: Ability and willingness to provide written informed consent prior to any study-related procedures.

Exclusion criteria

• Previous Therapy: Prior treatment with chemotherapy, radiation therapy, or immunotherapy for the current cancer diagnosis.
• Concurrent Malignancies: Presence of another active malignancy within the past 5 years (except for non-melanoma skin cancer or cervical carcinoma in situ).
• Active Infection: Presence of any uncontrolled infection requiring systemic therapy or serious co-morbid conditions that would compromise program compliance or interfere with study results.
• Allergies: Known hypersensitivity or contraindications to Omega-3 fatty acid supplementation or components of the immunotherapy regimen.
• Pregnancy/Breastfeeding: Women who are pregnant or breastfeeding; fertile men and women not employing effective contraception during the study period.

Psychiatric Condition: Any psychiatric condition or substance abuse that would interfere with compliance or affect the participant's safety.