HIPEC works by delivering heated chemotherapy directly to the peritoneal cavity, where the cancerous cells are located. The heat enhances the effect of the chemotherapy by: • Improving drug absorption: The heat increases the permeability of cancer cells, allowing chemotherapy to penetrate deeper into the tissue. • Direct targeting: By circulating chemotherapy directly in the abdominal cavity, the treatment targets the cancer more effectively while minimizing side effects to other parts of the body. • Enhanced chemotherapy action: Heat makes the chemotherapy drugs more potent, which may help kill cancer cells that were not removed by surgery.

HIPEC is used primarily for cancers that have spread to the peritoneum or abdominal cavity, especially when the cancer is confined to the abdomen but cannot be treated by traditional chemotherapy alone. It is often used in combination with surgery to remove visible tumors. The goal of HIPEC is to: • Treat peritoneal metastases: HIPEC is effective for cancers that have spread to the peritoneal lining but have not spread to distant organs. • Improve survival: For selected patients with cancers like colorectal, ovarian, or gastric cancer, HIPEC has been shown to improve survival rates compared to traditional chemotherapy alone. • Reduce recurrence: By targeting residual microscopic cancer cells left behind after surgery, HIPEC reduces the risk of cancer returning in the peritoneal cavity.

HIPEC offers several benefits, including: • Targeted treatment: Direct delivery of chemotherapy to the affected area allows for higher concentrations of the drug where it is most needed. • Enhanced effectiveness: The combination of surgery and heated chemotherapy improves the effectiveness of the treatment compared to systemic chemotherapy alone. • Reduced side effects: Because the chemotherapy is localized, it reduces the exposure to healthy tissues, potentially lowering the overall side effects of the treatment. • Improved survival: For some cancers, particularly those with peritoneal spread, HIPEC has been associated with longer survival rates.

HIPEC is most commonly used to treat cancers that have spread to the peritoneum (the lining of the abdominal cavity). These cancers include: • Colon cancer: In cases where cancer has spread to the peritoneum. • Ovarian cancer: For advanced ovarian cancer with peritoneal spread. • Gastric (stomach) cancer: When cancer spreads to the peritoneum or nearby organs. • Appendix cancer (Pseudomyxoma peritonei): A rare form of cancer that spreads in the abdomen. • Mesothelioma: A rare cancer of the lining of the abdomen or chest that can be treated with HIPEC in combination with surgery.

The HIPEC procedure is performed in two stages: 1. Surgical tumor removal: The first step is a surgery to remove as much of the visible tumor as possible. This may involve removing parts of affected organs, such as the colon, ovaries, or stomach. 2. Intraperitoneal chemotherapy: After tumor removal, the heated chemotherapy drugs are introduced into the peritoneal cavity. A special machine circulates the chemotherapy solution through the abdomen for about 60-90 minutes to allow it to target any remaining cancer cells. The procedure is done under general anaesthesia and usually takes several hours, depending on the extent of the surgery and chemotherapy.

Like any major surgery, HIPEC carries risks. Some potential risks and complications include: • Infection: Surgery on the abdominal cavity can lead to infections. • Bleeding: Significant bleeding can occur during surgery, especially when removing tumors from critical organs. • Damage to organs: Surrounding organs (such as the intestines, liver, or kidneys) may be injured during the surgery. • Chemotherapy side effects: Although chemotherapy is delivered directly to the abdomen, it can still cause side effects such as nausea, vomiting, and fatigue. • Bowel obstruction: The surgery may cause temporary or long-term changes in bowel function. • Fluid imbalance: The circulation of chemotherapy fluid can cause changes in fluid balance in the body. • Delayed recovery: As a complex procedure, recovery can take time, and some patients may need additional support during their recovery period.

Recovery from HIPEC surgery is typically longer and more involved than recovery from standard surgery. Key points in the recovery process include: • Hospital stay: Most patients will remain in the hospital for 1-2 weeks after the procedure, depending on the extent of the surgery and recovery. • Pain management: There may be significant discomfort following the surgery, but pain can usually be managed with medication. • Nutritional support: Because the abdominal organs may be affected by the surgery, some patients may require nutritional support, such as tube feeding, for a short time. • Monitoring for complications: Patients will be closely monitored for complications such as infection, bleeding, or bowel obstructions. • Gradual return to normal activities: Full recovery may take several months. Patients should avoid strenuous activity during this time and follow up with their oncologist regularly for checkups.

In most cases, HIPEC is part of a broader cancer treatment plan that may include: • Systemic chemotherapy: After HIPEC, patients may receive chemotherapy to target cancer cells that could have spread beyond the peritoneum. • Radiation therapy: Depending on the type and location of the cancer, radiation may be used to target any remaining cancer cells. • Follow-up care: Regular imaging and blood tests are necessary to monitor for recurrence of the cancer.

The success rates of HIPEC depend on several factors, including the type and stage of cancer, the patient’s overall health, and how well the surgery and chemotherapy are tolerated. For cancers like colon cancer with peritoneal metastasis, ovarian cancer, and appendix cancer, HIPEC has shown to improve survival rates and decrease the chances of cancer recurrence when compared to traditional treatments alone. Success rates are highest when the surgery can remove most or all of the visible cancer. Studies suggest that for patients with peritoneal carcinomatosis (cancer that has spread to the lining of the abdomen), HIPEC may extend survival by several years in some cases, compared to conventional chemotherapy.

HIPEC may not be suitable for patients with: 1. Extensive cancer spread: If the cancer has spread beyond the peritoneum to distant organs (like the liver, lungs, or bones), HIPEC may not be effective. 2. Unresectable tumors: If tumors cannot be surgically removed or reduced enough to allow for effective chemotherapy delivery, HIPEC may not be appropriate. 3. Poor overall health: Patients who are in poor health or have significant comorbidities may not be suitable candidates for a complex procedure like HIPEC. 4. Uncontrolled infection or active disease: If there is a severe infection or other active diseases, it may be risky to undergo HIPEC surgery.