Histologic evaluation of preventive measures for scald injury on the peritoneo-serosal surface due to intraoperative hyperthermic chemoperfusion for patients with gastric cancer and peritoneal metastasis

Effects of Hyperthermia and Hyperthermic Intraperitoneal Chemoperfusion on the Peritoneal and Tumor Immune Contexture

Hyperthermia combined with intraperitoneal (IP) drug delivery is increasingly used in the treatment of peritoneal metastases (PM). Hyperthermia enhances tumor perfusion and increases drug penetration after IP delivery. The peritoneum is increasingly recognized as an immune-privileged organ with its own distinct immune microenvironment. Here, we review the immune landscape of the healthy peritoneal cavity and immune contexture of peritoneal metastases. Next, we review the potential benefits and unwanted tumor-promoting effects of hyperthermia and the associated heat shock response on the tumor immune microenvironment. We highlight the potential modulating effect of hyperthermia on the biomechanical properties of tumor tissue and the consequences for immune cell infiltration. Data from translational and clinical studies are reviewed. We conclude that (mild) hyperthermia and HIPEC have the potential to enhance antitumor immunity, but detailed further studies are required to distinguish beneficial from tumor-promoting effects.

Local injection of M-CH combined with i.p. hyperthermic hypo-osmolar infusion is an effective therapy in advanced gastric cancer

Treatment failure of surgically treated gastric cancer is attributed to the spread of gastric cancer cells into the abdominal cavity and lymphatic or hematogenic canals. In the present study, local injection of mitomycin C bound to activated carbon (M-CH) combined with i.p. hyperthermic hypo-osmolar infusion (IPHHOI) was intraoperatively administered to prevent lymph node recurrence and peritoneal recurrence of gastric cancer. Between April 1998 and August 1999, 79 patients with advanced gastric cancer were allocated randomly to two groups. Forty patients underwent M-CH plus IPHHOI combined with surgery (M-CH1+IPHHOI group) and the remaining 39 underwent surgery alone (control group). Lymph node and peritoneal recurrence were significantly decreased in the M-CH1+IPHHOI group compared to that in the control group (p<0.05). The 1- and 2-year survival rates for the M-CH1+IPHHOI group were 91.2 and 72.1%, and those for the control group were 78.9 and 45.5%. The M-CH1IPHHOI group reaped a significant survival benefit (p=0.0352) compared to the control group. Although this study was conducted randomly for a small number of patients and short time, compared with the control group, the M-CH1+IPHHOI group had a beneficial effect in preventing lymph node recurrence and peritoneal recurrence after curative gastrectomy for advanced gastric cancer.