Intraperitoneal cytokine level in patients with peritoneal surface malignancies. A study of the RENAPE (French Network for Rare Peritoneal Malignancies).

BACKGROUND: Prognosis of peritoneal surface malignancies is influenced by the adequacy of surgical and chemotherapeutic treatment and by tumor spread at the time of diagnosis. By promoting morphological changes in the mesothelium, inflammatory cytokines reflect tumor biology and could be evaluated as biomarkers. Our objective was to evaluate intraperitoneal levels of IL-6, IL-8, IL-10, TNF-alpha, and sICAM in patients with pseudomyxoma peritonei and peritoneal mesothelioma.

METHODS: Serum and peritoneal fluid samples were prospectively collected in patients managed for peritoneal surface malignancies including pseudomyxoma peritonei (PMP), mesotheliomas, and other rare primitive peritoneal cancers (cancer group) and patients who underwent intraperitoneal laparoscopic surgical procedures for benign diseases (noncancer group). Samples were analyzed for IL-6, IL-8, IL-10, TNF-alpha, and sICAM concentrations. Correlations were assessed with tumor spread related clinical scores.

RESULTS: In both patient groups, intraperitoneal cytokine levels were higher than serum levels. Cancer patients had significantly higher intraperitoneal cytokine levels than noncancer patients. Peritoneal levels tended to increase in cancer patients with free tumor cells in peritoneal fluid. They were significantly higher in patients with tumor implants ≥2 cm and/or patients with peritoneal carcinomatosis index (PCI) >19. Furthermore, patients with malignant pseudomyxoma peritonei (grades II and III) had higher levels than patients with nonmalignant disease (grade I).

CONCLUSIONS: Assessment of intraperitoneal IL-6, IL-8, IL-10, TNF-alpha, and sICAM levels can be performed in patients with peritoneal surface malignancies. They can be considered as both diagnostic and prognostic biomarkers that could be used as useful adjuncts for therapeutic decision making.