Colorectal cancer is highly prevalent in France, ranking second among women and third among men. Its primary metastatic sites include the liver, lungs, and peritoneum. For peritoneal metastases, when the disease is moderately extensive, cytoreductive surgery is recommended in an expert centre. Following this procedure, the surgeon uses the CC-Score (Completeness of Cytoreduction after Surgery Score) to assess the completeness of surgical resection by evaluating the largest remaining tumor residue. This subjective score is currently the main prognostic factor for oncological outcomes post-surgery. However, there is no objective score based on biological criteria to evaluate the radicality of resection, despite the hypothesis that the micrometastatic component of the disease could be biologically assessed using appropriate circulating markers.

New biomarkers are emerging and appear relevant for determining the presence of tumor residual disease. Notable among these are circulating tumor DNA, which can detect mutated DNA released by tumor cells into the patient's blood through high-throughput sequencing, and new markers related to epigenetic modifications in cancer cells. These markers target specific nucleosomes or the transcription factor CTCF and show promise in detecting residual disease.

To effectively use these markers for constructing a biological score to detect residual disease in peritoneal carcinomatosis, it is essential to understand their perioperative kinetics. This is crucial because cellular debris release is expected post-surgery, necessitating the determination of the most relevant time point for measurement. Additionally, these markers appear to be correlated with blood inflammation levels, requiring a description of this correlation to account for this potential confounding factor. Finally, the sensitivity and specificity of these markers must be determined by studying their perioperative kinetics in patient groups undergoing surgeries other than cytoreductions for peritoneal carcinomatosis.

Inclusion Criteria:

• Common criteria:

  • Male/female over 18 years of age.
  • Weight ≥ 55 kg at inclusion.
  • Signature of a free and informed consent form.

• Specific criteria:

Group 1:

• Peritoneal metastases colorectal cancer histologically proven
• Synchronous or metachronous peritoneal metastases.
• Patients eligible for initial cytoreduction surgery.
• Non mucinous tumor (mucinous cells contingent <30%).

Group 2:

Colorectal cancer

Group 3:

Non-oncological chronic inflammatory diseases

Group 4:

Non-oncological chronic inflammatory diseases : parietal repairs, elective sigmoidectomy for diverticulosis

Group 5:

Abdominal sepsis conditions: peritonitis due to digestive perforation in non-oncological pathology, non-perforated appendicitis, cholecystitis.

Non inclusion Criteria:

• Patient with an active cancer (excluding colorectal cancer).
• Person with a progressive autoimmune disease.