Cytoreductive surgery (CRS) consists of peritonectomy procedures and multivisceral resections (exploration and debulking), depending on the extent of intra-abdominal tumor dissemination. (1) However, it is possible that following the removal of all visible tumors, there are microscopic cancer cells remaining in the surgical area. The surgical procedure may be followed intraoperatively by the infusion of hyperthermic chemotherapy or chemoperfusion, most commonly mitomycin C. Hyperthermia may be done as an adjunct to CRS. Inflow and outflow catheters are placed in the abdominal cavity, along with temperature probes to monitor the temperature. The skin is then temporarily closed during the chemotherapy perfusion, which typically runs for 1 to 2 hours. This procedure is referred to as hyperthermic intraperitoneal chemotherapy (HIPEC). Other methods of intraperitoneal chemotherapy include early postoperative intraperitoneal chemotherapy (EPIC).
HIPEC as an adjunct to surgical cytoreduction is designed to remove the invisible tumor deposits with intraperitoneal chemotherapy to address the remaining microscopic disease. By delivering chemotherapy intraperitoneally, drug exposure to the peritoneal surface is increased some 20-fold compared to systemic exposure. In addition, prior animal and in vitro studies have suggested that the cytotoxicity of mitomycin C is enhanced at temperatures greater than 39 degrees Celsius.
Peritoneal carcinomatosis from non-ovarian malignancies has long been regarded as a terminal disease with limited survival. In an attempt to prolong survival, aggressive locoregional therapy, such as combining CRS with HIPEC, has been used.
The following are peritoneal carcinomatosis addressed by using CRS with HIPEC:
Pseudomyxoma peritonei is a clinicopathologic entity characterized by the production of mucinous ascites and mostly originates from epithelial neoplasms of the appendix. As the tumor grows, the narrow lumen of the appendix becomes obstructed and subsequently leads to appendiceal perforation. The neoplastic cells progressively colonize the peritoneal cavity and copious mucin production builds up in the peritoneal cavity. Appendix tumors causing pseudomyxoma peritonei range from a benign pathologic appearance (disseminated peritoneal adenomucinosis) to malignant pathologic findings (peritoneal mucinous carcinomatosis), with some intermediate pathologic grades. Clinically, this syndrome ranges from early pseudomyxoma peritonei, fortuitously discovered on imaging or during a laparotomy performed for another reason, to advanced cases with a distended abdomen, bowel obstruction, and starvation. The conventional treatment of pseudomyxoma peritonei is surgical debulking repeated as necessary to alleviate pressure effects. However, repeated debulking surgeries become ever more difficult due to progressively thickened intra-abdominal adhesions, and this treatment is palliative, leaving visible or occult disease in the peritoneal cavity. (2)
Malignant mesothelioma is a relatively uncommon malignancy that may arise from the mesothelial cells lining the pleura, peritoneum, pericardium, and tunica vaginalis testis. In the U.S., 200-400 new cases of diffuse malignant peritoneal mesothelioma (DMPM) are registered every year, accounting for 10-30% of all-type mesothelioma. (3) DMPM has traditionally been considered as a rapidly lethal malignancy with limited and ineffective therapeutic options. (3) The disease is usually diagnosed at an advanced stage and is characterized by multiple variably sized nodules throughout the abdominal cavity. As the disease progresses, the nodules become confluent to form plaques, masses, or uniformly cover peritoneal surfaces. In most patients, death eventually occurs as a result of locoregional progression within the abdominal cavity. In historical case series, treatment by palliative surgery, systemic/intraperitoneal chemotherapy, and abdominal irradiation results in a median survival of approximately 12 months. (3)
Colorectal Cancer and Peritoneal Carcinomatosis
Peritoneal dissemination develops in approximately 10–15% of patients with colon cancer, and despite the use of increasingly effective regimens of chemotherapy and biologic agents in the treatment of advanced disease, peritoneal metastases are associated with a median survival of 6 to 7 months.