Investigators intend to utilize clinical data from the Department of Oncology at Jiangsu Provincial People's Hospital to analyze changes in body composition in digestive system tumor patients before and after receiving anti-tumor drug treatment. Investigators aim to uncover the association between baseline body composition and overall/progression-free survival in patients with digestive system tumors. Additionally, Investigators plan to investigate the relationship between changes in body composition during anti-tumor drug treatment (chemotherapy and immunotherapy) and the prognosis of tumor patients.

Inclusion Criteria:

• Male or female patients aged between 18 and 85 years old.

• Patients with histologically confirmed digestive tract cancers, such as esophageal cancer, gastric cancer, small intestinal cancer, colorectal cancer, as well as pancreatic cancer, liver cancer, gallbladder cancer, etc.

• Patients admitted for anti-tumor-related drug treatment.

• Expected survival period of more than three months.

• ECOG PS score: < 4.

• No severe psychological disorders, physical disabilities, dementia, Alzheimer's disease, pulmonary tuberculosis, HIV/AIDS, or other infectious diseases.

• Patients must have sufficient organ and bone marrow function, meeting the following criteria:

  1. Hematological criteria:

     Hemoglobin (Hb) ≥ 90 g/L (without blood transfusion in the past 28 days). Absolute neutrophil count (ANC) ≥ 1.5×109/L. Peripheral blood monocytes > 1500mm3. Platelet count (PLT) ≥ 100×109/L.

  2. Biochemical criteria:

     Total bilirubin (TBIL) ≤ 1.5 × the upper limit of normal (ULN). ALT and AST ≤ 2.5×ULN; if there is liver metastasis, ALT and AST ≤ 5×ULN. Creatinine (Cr) ≤ 1.5×ULN or creatinine clearance rate (CCr) ≥ 60 ml/min (Cockcroft-Gault formula).

  3. Coagulation function is sufficient, defined as international normalized ratio (INR) or prothrombin time (PT) ≤ 1.5 × ULN.

• Women of childbearing potential must have a negative pregnancy test (serum or urine) within seven days before enrollment and must voluntarily use appropriate contraception methods during the observation period and within six months after the last dose.

• Signed informed consent.

Exclusion Criteria:

• Female patients who are pregnant or breastfeeding.
• Patients with accompanying diseases, as judged by the investigator, pose a serious risk to patient safety or may affect the patient's ability to complete the study.
• Patients with poor compliance who refuse to undergo body composition measurements.
• Patients who experience a severe adverse event judged by the investigator as no longer suitable for continued participation in the study or those who become unexpectedly pregnant.
• Patients who are unwilling to continue in the clinical trial and insist on withdrawal.
• The investigator deems it necessary to terminate the study.
• Patients who were mistakenly included but did not meet the criteria.

This prospective study includes digestive system tumor patients treated in the elderly comprehensive ward of Jiangsu Provincial People's Hospital from April 2023 to September 2024. Baseline surveys were conducted between April and May 2023 and between September and October 2024.